Gene Summary

Gene:KRAS; KRAS proto-oncogene, GTPase
Aliases: NS, NS3, CFC2, RALD, KRAS1, KRAS2, RASK2, KI-RAS, C-K-RAS, K-RAS2A, K-RAS2B, K-RAS4A, K-RAS4B, c-Ki-ras2
Summary:This gene, a Kirsten ras oncogene homolog from the mammalian ras gene family, encodes a protein that is a member of the small GTPase superfamily. A single amino acid substitution is responsible for an activating mutation. The transforming protein that results is implicated in various malignancies, including lung adenocarcinoma, mucinous adenoma, ductal carcinoma of the pancreas and colorectal carcinoma. Alternative splicing leads to variants encoding two isoforms that differ in the C-terminal region. [provided by RefSeq, Jul 2008]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:GTPase KRas
Source:NCBIAccessed: 10 March, 2017


What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 10 March 2017 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

Tag cloud generated 10 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (12)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Entity Topic PubMed Papers
Colorectal CancerKRAS and Colorectal Cancer View Publications2138
Lung CancerKRAS and Lung Cancer View Publications1345
Lung Cancer, Non-Small CellKRAS and Non-Small Cell Lung Cancer View Publications712
Pancreatic CancerKRAS and Pancreatic Cancer View Publications548
Thyroid CancerKRAS and Thyroid Cancer View Publications124
Stomach CancerKRAS and Stomach Cancer View Publications117
Skin CancerKRAS and Skin Cancer View Publications106
Urinary System CancersKRAS and Urinary System Cancers View Publications81
Noonan SyndromeKRAS mutation in Noonan Syndrome
Noonan Syndrome is an autosamal dominant multi-system disorder, characterised by facial anomalies, short stature, developmental delay, cardiac abnormalities and other symptoms. The syndrome pre-disposes to myeloproliferative disorders ( mainly chronic myeolomonocytic leukemia / juvenile myelomonocytic leukemia and acute lymphoblastic leukemia), with reports of neuroblastoma, rhabdomyosarcoma and a wide range of other tumors.
View Publications14
-KRAS and Noonan Syndrome View Publications13
Ovarian CancerKRAS and Ovarian Cancer View Publications205
Rectal CancerKRAS and Rectal Cancer View Publications99

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: KRAS (cancer-related)

Jauhri M, Bhatnagar A, Gupta S, et al.
Prevalence and coexistence of KRAS, BRAF, PIK3CA, NRAS, TP53, and APC mutations in Indian colorectal cancer patients: Next-generation sequencing-based cohort study.
Tumour Biol. 2017; 39(2):1010428317692265 [PubMed] Related Publications
Colorectal cancer incidences are on a rise in India. In this study, we have analyzed the mutation frequencies of six potential biomarkers, their coexistence, association with clinicopathological characteristics, and tumor location in Indian colorectal cancer patients. Next-generation sequencing was performed to identify mutations in the six potential biomarker genes using formalin-fixed paraffin-embedded tissue blocks of 112 colorectal cancer patients. The mutation frequency observed in KRAS, BRAF, PIK3CA, NRAS, TP53, and APC was 35.7%, 7.1%, 16.1%, 6.3%, 39.3%, and 29.5%, respectively. The significant associations of mutations were KRAS with age less than 60 years (p = 0.041), PIK3CA with males (p = 0.032), tumor stage I-II (p = 0.013), lack of metastasis in lymph nodes (p = 0.040), NRAS with rectum (p = 0.002), and APC with T2 stage of tumor growth (p = 0.013). No single patient harbored mutations in these six genes or any five genes simultaneously. Significance was noted in coexistence of KRAS with APC (p = 0.024) and mutual exclusion of KRAS with BRAF (p = 0.029). PIK3CA exon 9 was observed to be more frequently associated with KRAS mutations than PIK3CA exon 20 (p = 0.072). NRAS mutations were mutually exclusive with BRAF and PIK3CA mutations. As per our knowledge, this is the first next-generation sequencing-based biomarker study in Indian colorectal cancer patients. Frequent coexistence of gene mutations in pairs and triplets suggests that synergistic effect of overlapping mutations might further trigger the disease. In addition, infrequent coexistence of multiple gene mutations hints toward different signaling pathways for colorectal cancer tumorigenesis.

Zekri J, Al-Shehri A, Mahrous M, et al.
Mutations in codons 12 and 13 of K-ras exon 2 in colorectal tumors of Saudi Arabian patients: frequency, clincopathological associations, and clinical outcomes.
Genet Mol Res. 2017; 16(1) [PubMed] Related Publications
Mutations in codons 12/13 of K-ras exon 2 are associated with reduced benefit from anti-epidermal growth factor receptor antibody treatment for metastatic colorectal cancer (CRC). Here, we evaluated the frequency of K-ras mutations and their relationship with clinicopathological features and treatment outcomes in Saudi Arabian patients with CRC. The genetic status of K-ras was determined in 300 patients diagnosed with CRC. Clinical information was collected retrospectively. K-ras was wild-type in 58% and mutated in 42% of the tumors. Most mutations were at codon 12 (89%) and were associated with metastasis [odds ratio (OR) = 1.38 (95%CI = 1.14-1.67] and occurrence of >40 µg/L carcinoembryonic antigen (CEA) [OR = 1.33 (1.1-1.74)] during diagnosis. Patients in stages I-III of the disease with wild-type K-ras tumors had a median relapse free survival (RFS) of 29 months in contrast to 22 months for those with the mutated K-ras tumor (P = 0.0357). In multivariate analysis, only the stage of the disease significantly predicted RFS (P = 0.001). Patients in stage IV of CRC with the wild-type K-ras tumor did not reach the median overall survival (OS), whereas patients with the mutated K-ras tumor survived for 23.5 months (P = 0.044). CEA level >40 µg/L (P = 0.004) and status of K-ras (P = 0.044) were independent predictors of OS. This is the largest study investigating K-ras mutations in patients with CRC in the Middle East. Mutations were associated with advanced stage of CRC, higher serum CEA, shorter RFS and OS.

Galanopoulos M, Papanikolaou IS, Zografos E, et al.
Comparative Study of Mutations in Single Nucleotide Polymorphism Loci of KRAS and BRAF Genes in Patients Who Underwent Screening Colonoscopy, With and Without Premalignant Intestinal Polyps.
Anticancer Res. 2017; 37(2):651-657 [PubMed] Related Publications
AIM: Our aim was to perform a comparison study of the mutation rate of V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), and v-Raf murine sarcoma viral oncogene homolog-B (BRAF) genes between blood-based cell-free DNA (cfDNA), and tissue sample biopsies in individuals undergoing screening colonoscopy.
MATERIALS AND METHODS: All specimens were collected from January 2015 to January 2016. A total of 92 blood samples and colonic biopsy specimens were collected from healthy individuals with no polyps undergoing screening colonoscopy (group A, n=35), patients with colorectal cancer (group B, n=27), and patients with neoplastic intestinal polyps (group C, n=30). Peripheral blood was collected from each patient and a focal tissue biopsy was conducted.
RESULTS: We only found a limited statistically significant difference (p=0.046) in the mutation analysis for codon 12 of the KRAS gene when we compared tissue biopsies from patients in group B to those from group C. In the blood samples, only the rate of mutation in codon 12 of the KRAS gene in samples of group B was significantly higher than that in group A (p=0.013).
CONCLUSION: Blood cfDNA may be a promising tool in CRC screening as it may discriminate patients with CRC compared to healthy individuals and those with colonic polyps, even though it does not appear useful in predicting the presence of colonic polyps.

Hsieh R, Nico MM, Camillo CM, et al.
Mutational Status of NRAS and BRAF Genes and Protein Expression Analysis in a Series of Primary Oral Mucosal Melanoma.
Am J Dermatopathol. 2017; 39(2):104-110 [PubMed] Related Publications
Primary oral mucosal melanoma is an extremely rare and aggressive tumor arising from melanocytes located in the mucosal epithelium of the oral cavity. Although malignant melanoma of oral mucosa shares some clinical features with its cutaneous counterpart, it has been associated with a worst prognosis; its etiopathogenesis are still only partially unraveled as there is no influence of UV radiation. It is known that the mitogen-activated protein kinase pathway mediates cellular responses to growth signals and its activation is an important phenomenon in melanoma. The aim of this study was to evaluate NRAS and BRAF genes, both components of mitogen-activated protein kinase molecular pathway, and compare with their protein expression. Point mutations of NRAS (codons 12, 13, and 61) and BRAF (codon 600) were screened by pyrosequencing method, and its results were associated to the protein expression of RAS and BRAF performed by immunohistochemistry. The authors observed mutation in BRAF 600 (3/14), NRAS codons 12 and 13 (2/14), and NRAS codon 61 (2/8). One case showed positive RAS protein expression, but no mutation was observed. Twelve in 14 cases showed positive BRAF protein expression: 3 cases showed BRAF mutation; 2 cases showed NRAS codon 61 mutation; 2 cases showed NRAS codons 12 and 13 mutation but not simultaneously. Although NRAS and BRAF mutation frequency and RAS protein expression are low, BRAF protein expression was intense; probably, NRAS and BRAF mutations are independent events and alternative molecular mechanisms in the primary oral mucosal melanoma tumorigenesis.

Hecht SS
Oral Cell DNA Adducts as Potential Biomarkers for Lung Cancer Susceptibility in Cigarette Smokers.
Chem Res Toxicol. 2017; 30(1):367-375 [PubMed] Free Access to Full Article Related Publications
This perspective considers the use of oral cell DNA adducts, together with exposure and genetic information, to potentially identify those cigarette smokers at highest risk for lung cancer, so that appropriate preventive measures could be initiated at a relatively young age before too much damage has been done. There are now well established and validated analytical methods for the quantitation of urinary and serum metabolites of tobacco smoke toxicants and carcinogens. These metabolites provide a profile of exposure and in some cases lung cancer risk, but they do not yield information on the critical DNA damage parameter that leads to mutations in cancer growth control genes such as KRAS and TP53. Studies demonstrate a correlation between changes in the oral cavity and lung in cigarette smokers, due to the field effect of tobacco smoke. Oral cell DNA is readily obtained in contrast to DNA samples from the lung. Studies in which oral cell DNA and salivary DNA have been analyzed for specific DNA adducts are reviewed; some of the adducts identified have also been previously reported in lung DNA from smokers. The multiple challenges of developing a panel of oral cell DNA adducts that could be routinely quantified by mass spectrometry are discussed.

Mikhailenko DS, Efremov GD, Safronova NY, et al.
Detection of Rare Mutations by Routine Analysis of KRAS, NRAS, and BRAF Oncogenes.
Bull Exp Biol Med. 2017; 162(3):375-378 [PubMed] Related Publications
Molecular genetic analysis of KRAS, NRAS, and BRAF genes was carried out in order to develop an optimal algorithm for detection of minor mutations. We analyzed 35 melanoma and 33 colorectal cancer specimens. Frequent G12D/V/A/C/S mutations were detected in KRAS. The most frequent BRAF mutation in melanoma was V600E, the percentage of rare mutations is significant for DNA diagnosis (24%). Identification of rare BRAF mutations 1790C→G (L597R), 1798_1799delinsAA (V600K), 1798_1799delinsAG (V600R), and 1799_1800delinsAA (V600E) and NRAS mutation 38G→T (G13V) was possible only by Sanger sequencing. The combination of real-time PCR and sequencing can improve analysis sensitivity and ensure concordance of the tested loci with the international recommendations.

Cicenas J, Tamosaitis L, Kvederaviciute K, et al.
KRAS, NRAS and BRAF mutations in colorectal cancer and melanoma.
Med Oncol. 2017; 34(2):26 [PubMed] Related Publications
Cancers are the group of diseases, which arise because of the uncontrolled behavior of some of the genes in our cells. There are possibilities of gene amplifications, overexpressions, deletions and other anomalies which might lead to the development and spread of cancer. One of the most dangerous ways to the cancers is the mutations of the genes. The mutated genes can start unstoppable proliferation of cells, their uncontrolled motility, protection from apoptosis, the DNA mutation enhancement as well as other anomalies, leading to the cancer. This review focuses on the genes, which are frequently mutated in various cancers and are known to be important in the advance and progression of colorectal cancer and melanoma, namely KRAS, NRAS and BRAF.

Laczmanska I, Skiba P, Karpinski P, et al.
Customized Array Comparative Genomic Hybridization Analysis of 25 Phosphatase-encoding Genes in Colorectal Cancer Tissues.
Cancer Genomics Proteomics. 2017; 14(1):69-74 [PubMed] Free Access to Full Article Related Publications
BACKGROUND/AIM: Molecular mechanisms of alterations in protein tyrosine phosphatases (PTPs) genes in cancer have been previously described and include chromosomal aberrations, gene mutations, and epigenetic silencing. However, little is known about small intragenic gains and losses that may lead to either changes in expression or enzyme activity and even loss of protein function.
MATERIALS AND METHODS: The aim of this study was to investigate 25 phosphatase genes using customized array comparative genomic hybridization in 16 sporadic colorectal cancer tissues.
RESULTS: The analysis revealed two unique small alterations: of 2 kb in PTPN14 intron 1 and of 1 kb in PTPRJ intron 1. We also found gains and losses of whole PTPs gene sequences covered by large chromosome aberrations.
CONCLUSION: In our preliminary studies using high-resolution custom microarray we confirmed that PTPs are frequently subjected to whole-gene rearrangements in colorectal cancer, and we revealed that non-polymorphic intragenic changes are rare.

Sim EU, Chan SL, Ng KL, et al.
Human Ribosomal Proteins RPeL27, RPeL43, and RPeL41 Are Upregulated in Nasopharyngeal Carcinoma Cell Lines.
Dis Markers. 2016; 2016:5179594 [PubMed] Free Access to Full Article Related Publications
Apart from their canonical role in ribosome biogenesis, there is increasing evidence of ribosomal protein genes' involvement in various cancers. A previous study by us revealed significant differential expression of three ribosomal protein genes (RPeL27, RPeL41, and RPeL43) between cell lines derived from tumor and normal nasopharyngeal epithelium. However, the results therein were based on a semiquantitative assay, thus preliminary in nature. Herein, we provide findings of a deeper analysis of these three genes in the context to nasopharyngeal carcinoma (NPC) tumorigenesis. Their expression patterns were analyzed in a more quantitative manner at transcript level. Their protein expression levels were also investigated. We showed results that are contrary to previous report. Rather than downregulation, these genes were significantly overexpressed in NPC cell lines compared to normal control at both transcript and protein levels. Nevertheless, their association with NPC has been established. Immunoprecipitation pulldown assays indicate the plausible interaction of either RPeL27 or RPeL43 with POTEE/TUBA1A and ACTB/ACTBL2 complexes. In addition, RPeL43 is shown to bind with MRAS and EIF2S1 proteins in a NPC cell line (HK1). Our findings support RPeL27, RPeL41, and RPeL43 as potential markers of NPC and provide insights into the interaction targets of RPeL27 and RPeL43 proteins.

Rodriguez-Salas N, Dominguez G, Barderas R, et al.
Clinical relevance of colorectal cancer molecular subtypes.
Crit Rev Oncol Hematol. 2017; 109:9-19 [PubMed] Related Publications
Colorectal cancer (CRC) is characterized by alteration of critical pathways such TP53 inactivation, BRAF, PI3CA mutations, APC inactivation, KRAS, TGF-β, CTNNB mutations, disregulation of Epithelial to mesnechymal transition (EMT) genes, WNT signaling activation, MYC amplification, and others. Differences in these molecular events results in differences in phenotypic characteristics of CRC, that have been studied and classified by different models of molecular subtypes. It could have potential applications to prognosis, but also to therapeutical approaches of the CRC patients. We review and summarized the different molecular classifications and try to clarify their clinical and therapeutical relevance.

Xu H, Wu D, Li CQ, et al.
Label-free colorimetric detection of cancer related gene based on two-step amplification of molecular machine.
Biosens Bioelectron. 2017; 90:314-320 [PubMed] Related Publications
Highly sensitive detection of K-ras gene is of great significance in biomedical research and clinical diagnosis. Here, we developed a colorimetric biosensing system for the detection of proto-oncogene K-ras based on enhanced amplification effect of DNA molecular machine, where dual isothermal circular strand-displacement amplification (D-SDA) occurs on two arms in one-to-one correspondence. Specifically, we designed a primer-locked hairpin probe (HP) and a primer-contained linear polymerization template (PPT). In the presence of target gene, HP can hybridize with PPT, forming a DNA molecular machine with dual functional arms (called DFA-machine). Each of the two probes in this machine is able to be extended by polymerase on its counterpart species. Moreover, with the help of nicking endonuclease, the dual isothermal polymerization is converted into dual circular strand-displacement amplification, generating a large amount of anti-hemin aptamer-contained products. After binding to hemins, the aptamer/hemin duplex, horseradish peroxidase (HRP)-mimicking DNAzyme, was formed and catalyzed the oxidation of colorless ABTS by H2O2, producing a visible green color. The proposed colorimetric assay exhibits a wide linear range from 0.01 to 150nM with a low detection limit of 10pM. More interestingly, the mutations existing in target gene are easily observed by the naked eye. It should be noted that this colorimetric system was proved by the analysis of K-ras gene of SW620 cell lines. The simple and powerful DFA-machine is expected to provide promising potential in the sensitive detection of biomarkers for cancer diagnosis, prognosis and therapy.

Amann VC, Ramelyte E, Thurneysen S, et al.
Developments in targeted therapy in melanoma.
Eur J Surg Oncol. 2017; 43(3):581-593 [PubMed] Related Publications
Melanomas are disease entities driven in part by the mitogen activated protein kinase (MAPK) pathway. The TCGA network recently defined four genetic subtypes based on the most prevalent significantly mutated genes, including mutant BRAF, mutant RAS (N/H/K), mutant NF1, and Triple wild-type melanoma (harboring none of the aforementioned mutations, but instead includes KIT, GNA and GNAQ mutations). The successful development of kinase inhibitors marked a milestone in the treatment of metastatic melanoma. Combination treatment with a BRAF- and MEK-inhibitor is the current standard of care for inoperable stage IIIC/IV BRAF-mutated melanoma. Recent data demonstrate excellent long-term outcome, especially in patients with normal baseline LDH levels, and confirm that there is a subset of BRAF inhibitor-naive patients who experience durable responses without progression on combination treatment. In the future, adding a third compound based on individual genetic alterations might further improve the outcome of targeted therapy.

Pectasides D, Kotoula V, Papaxoinis G, et al.
Expression Patterns of Growth and Survival Genes with Prognostic Implications in Advanced Pancreatic Cancer.
Anticancer Res. 2016; 36(12):6347-6356 [PubMed] Related Publications
AIM: The aim of this study was to evaluate the mRNA expression pattern of growth- and survival-related genes and assess their prognostic significance in patients with advanced pancreatic cancer.
PATIENTS AND METHODS: In total, 98 patients were included in this retrospective translational research study and were evaluated for Kirsten rat sarcoma viral oncogene homolog (KRAS) mutational status, and v-akt murine thymoma viral oncogene homolog 1 (AKT1), AKT serine/threonine kinase 2 (AKT2), AKT serine/threonine kinase 3 (AKT3), cyclin D1 (CCND1), epidermal growth factor receptor (EGFR), mitogen-activated protein kinase 1 (MAPK1), hepatocellular growth factor receptor (MET), avian myelomatosis viral oncogene homolog (MYC), nuclear factor kappa B subunit 1 (NFKb1), phosphatase and tensin homolog (PTEN) and mechanistic target of rapamycin (FRAP1) genes mRNA expression. Among these patients, 73 received first-line gemcitabine combined with erlotinib (N=57) or gefitinib (N=16).
RESULTS: KRAS mutation did not correlate with mRNA gene expression. Unsupervised hierarchical clustering according to mRNA gene expression successfully distinguished four prognostically distinct groups of tumors. Overexpression of all genes was associated with best prognosis, while suppression or heterogeneous expression patterns of the examined genes were associated with expression patterns of growth- and survival-related genes, classifying pancreatic tumors into distinct groups with possibly different outcomes.

Aldiab A, Al Khayal KA, Al Obaid OA, et al.
Clinicopathological Features and Predictive Factors for Colorectal Cancer Outcome in the Kingdom of Saudi Arabia.
Oncology. 2017; 92(2):75-86 [PubMed] Related Publications
BACKGROUND/AIMS: Colorectal cancer (CRC) is the most frequent cancer and a leading cause of cancer death in the Kingdom of Saudi Arabia (KSA). To date, no nationwide screening programs have been adopted. This prospective, longitudinal study investigated factors influencing the outcome of CRC in Saudi patients.
METHODS: Patients completed a CRC awareness questionnaire. Colonoscopy, CT/MRI, histopathology of tumor biopsies, and KRAS and BRAF testing were performed. Patients were treated according to their stage. All patients were followed until the end of the study and 3- and 5-year survival was assessed.
RESULTS: Sixty percent of study patients with sporadic CRC presented with significantly advanced disease (stages III and IV) with or without metastases at entry. Patients showed low levels of awareness of the risk factors and signs of CRC. Patients presented at a median age of 50 years. Family history of CRC and ulcerative colitis were positive in 11 and 6% of patients, respectively. Stage III/IV tumors with distant metastases at enrollment, right-sided tumors, mucinous tumors, lymphovascular invasion, and KRAS (51%) or BRAF (28%) mutations predicted poor prognosis and survival.
CONCLUSION: CRC in KSA is usually diagnosed at advanced stages with metastases and KRAS/BRAF, and is associated with poor prognosis and short survival. Nationwide awareness campaigns and screening programs for CRC are critical for prevention, early detection and adequate management of CRC.

Li Y, Peng Y, Jiang X, et al.
Whole exome sequencing of thymic neuroendocrine tumor with ectopic ACTH syndrome.
Eur J Endocrinol. 2017; 176(2):187-194 [PubMed] Related Publications
OBJECTIVE: Thymic neuroendocrine tumor is the second-most prevalent cause of ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS), which is a rare disease characterized by ectopic ACTH oversecretion from nonpituitary tumors. However, the genetic abnormalities of thymic neuroendocrine tumors with EAS remain largely unknown. We aim to elucidate the genetic abnormalities and identify the somatic mutations of potential tumor-related genes of thymic neuroendocrine tumors with EAS by whole exome sequencing.
DESIGN AND METHODS: Nine patients with thymic neuroendocrine tumors with EAS who were diagnosed at Shanghai Clinical Center for Endocrine and Metabolic Diseases in Ruijin Hospital between 2002 and 2014 were enrolled. We performed whole exome sequencing on the DNA obtained from thymic neuroendocrine tumors and matched peripheral blood using the Hiseq2000 platform.
RESULTS: We identified a total of 137 somatic mutations (median of 15.2 per tumor; range, 1-24) with 129 single-nucleotide mutations (SNVs). The predominant substitution in these mutations was C:G > T:A transition. Approximately 80% of detected mutations resulted in amino acid changes. However, we failed to discover any recurrent mutations in these nine patients. By functional predictions, HRAS, PAK1 and MEN1, previously reported in neuroendocrine tumors, were identified as candidate tumor-related genes associated with thymic neuroendocrine tumors.
CONCLUSIONS: Using whole exome sequencing, we identified genetic abnormalities in thymic neuroendocrine tumors with EAS. Thereby, this study acts as a further supplement of the genetic features of neuroendocrine tumors. Somatic mutations of three potential tumor-related genes (HRAS, PAK1 and MEN1) might contribute to the tumorigenesis of thymic neuroendocrine tumors with EAS.

Kameyama H, Shimada Y, Ichikawa H, et al.
[New Classification for Advanced Colorectal Cancer Using CancerPlex®Genomic Tests].
Gan To Kagaku Ryoho. 2016; 43(11):1361-1365 [PubMed] Related Publications
Recently, targeted drugs have been developed for the treatment of colorectal cancer(CRC). Among targets, it is well known that KRAS mutations are associated with resistance to epidermal growth factor receptor(EGFR)monoclonal antibodies. However, response rates using anti-EGFR monotherapy for CRC were less than 20-30% in previous clinical studies. Thus, because the RAS/MAP2K/MAPK and PI3K/AKT pathways are associated with CRC resistance to chemotherapy, we analyzed gene mutations in Stage IV CRC patients using a genomic test(CancerPlex®). Medical records were reviewed for 112 patients who received treatment for CRC between 2007 and 2015 in Niigata University Medical and Dental Hospital or Niigata Cancer Center Hospital. There were 66 male and 46 female patients, and their median age was 62.5(range, 30-86) years. Cluster analyses were performed in 110 non-hypermutated Japanese CRC patients using Euclidean distance and Ward's clustering method, and 6 typical groups were identified. Among these, patients with all wild-type actionable genes benefited from anti-EGFR therapies. The expense of targeted drugs warrants consideration of cost-effectiveness during treatment decision-making for advanced CRC patients. To this end, based on the genetic information on CRC, it is possible to develop precision medicine using CancerPlex®.

Hayashi H, Nishihara H
[A Novel Treatment Strategy for Pancreatic Cancer Based on Gene Profiles].
Gan To Kagaku Ryoho. 2016; 43(11):1326-1331 [PubMed] Related Publications
Pancreatic cancer has one of the highest rates of mortality among malignancies and the development of promising future therapies is strongly required. Recently, the utility of gene aberrations as biomarkers for determining therapeutic strategies has been demonstrated in several types of cancer. The detection of druggable mutations that aid in the selection of effective molecular targeting drugs is feasible in clinical settings for certain cancers. On the other hand, personalized therapy for pancreatic cancer guided by genomic biomarkers has not yet been realized and suitable molecular targets for the disease have been unclear until now. KRAS, CDKN2A, TP53, and SMAD4 have been recognized as major driver genes in pancreatic carcinogenesis. However, it is considered difficult to develop treatment strategies to target genetic aberrations of these four genes. In recent years, genome sequencing has progressively revealed the molecular biological characteristics of pancreatic cancer, including the discovery of novel potential therapeutic targets and low-frequency druggable genetic aberrations. Gene profilebased novel treatment strategies and subsequent attempts to realize precision medicine for pancreatic cancer are steadily ongoing in an effort to achieve improved treatment outcomes.

Kacerovska D, Drlik L, Slezakova L, et al.
Cutaneous Sebaceous Lesions in a Patient With MUTYH-Associated Polyposis Mimicking Muir-Torre Syndrome.
Am J Dermatopathol. 2016; 38(12):915-923 [PubMed] Related Publications
A 76-year-old white male with a history of adenocarcinoma of the rectosigmoideum and multiple colonic polyps removed at the age of 38 and 39 years by an abdominoperitoneal amputation and total colectomy, respectively, presented with multiple whitish and yellowish papules on the face and a verrucous lesion on the trunk. The lesions were surgically removed during the next 3 years and a total of 13 lesions were investigated histologically. The diagnoses included 11 sebaceous adenomas, 1 low-grade sebaceous carcinoma, and 1 squamous cell carcinoma. In some sebaceous lesions, squamous metaplasia, intratumoral heterogeneity, mucinous changes, and peritumoral lymphocytes as sometimes seen in sebaceous lesions in Muir-Torre syndrome were noted. Mutation analysis of the peripheral blood revealed a germline mutation c.692G>A,p.(Arg231His) in exon 9 and c.1145G>A, p.(Gly382Asp) in exon 13 of the MUTYH gene. A KRAS mutation G12C (c.34G>T, p.Gly12Cys) was detected in 1 sebaceous adenoma and a NRAS mutation Q61K (c.181C>A, p.Gln61Lys) was found in 2 other sebaceous adenomas. No germline mutations in MLH1, MSH2, MSH6 and PMS2 genes, no microsatellite instability, no aberrant methylation of MLH1 promoter, and no somatic mutations in MSH2 and MSH6 were found. An identical MUTYH germline mutation was found in the patient's daughter. Despite striking clinicopathological similarities with Muir-Torre syndrome, the molecular biologic testing confirmed the final diagnosis of MUTYH-associated polyposis.

Tatarian T, Winter JM
Genetics of Pancreatic Cancer and Its Implications on Therapy.
Surg Clin North Am. 2016; 96(6):1207-1221 [PubMed] Related Publications
Over the past decade, emerging technologies have provided new insights into the genomic landscape of pancreatic ductal adenocarcinoma (PDA). In addition to the commonly recognized genetic drivers of pancreatic carcinogenesis (KRAS, CDKN2A, TP53, SMAD4), new genes and pathways have been implicated. However, these efforts have not identified any new high-frequency actionable mutations, limiting the success of mutation-targeted therapy in PDA. This article provides a report on the current landscape of pancreas cancer genetics and targeted therapeutics.

Sartore-Bianchi A, Siena S, Tonini G, et al.
Overcoming dynamic molecular heterogeneity in metastatic colorectal cancer: Multikinase inhibition with regorafenib and the case of rechallenge with anti-EGFR.
Cancer Treat Rev. 2016; 51:54-62 [PubMed] Related Publications
In metastatic colorectal cancer (mCRC), fluorouracil-based combination therapy with oxaliplatin or irinotecan is the mainstay of first-line treatment. Patient survival has been significantly improved with the introduction of monoclonal antibodies against VEGF (bevacizumab), VEGFR2 (ramucirumab) or EGFR (cetuximab or panitumumab) in first- and second-line therapies. However, all patients treated with chemotherapy and targeted therapies will eventually relapse, and recently the emergence of alterations in EGFR, RAS, BRAF, ERB-B2, MET and possibly in other genes has been shown to jeopardize response to EGFR blockade. In chemorefractory patients, multikinase inhibition with regorafenib has proved to be effective and rechallenge with chemotherapy or anti-EGFR agents is empirically pursued. This review will critically discuss how the evolving knowledge of mechanisms of resistance driven by intratumoural dynamic molecular heterogeneity can impact on rational choice of treatments in this setting.

Ejima-Yamada K, Oshiro Y, Okamura S, et al.
Epstein-Barr virus infection and gene promoter hypermethylation in rheumatoid arthritis patients with methotrexate-associated B cell lymphoproliferative disorders.
Virchows Arch. 2017; 470(2):205-215 [PubMed] Related Publications
We analyzed CpG-island hypermethylation status in 12 genes of paraffin-embedded tissues from 38 rheumatoid arthritis (RA) patients with methotrexate (MTX)-associated large B cell lymphoproliferative disorder (BLPD), 11 RA patients with non-MTX-associated BLPD (non-MTX-BLPD), 22 controls with diffuse large B cell lymphoma (DLBCL), and 10 controls with Epstein-Barr virus (EBV)(+) DLBCL. Among them, tumor cells from EBV(+) MTX-BLPD patients and control EBV(+) DLBCL patients had significantly lower median incidence of CpG island methylator phenotype (CIMP) than those from non-MTX-BLPD and control DLBCL groups (2.3 and 1.7 vs. 4.3 and 4.4; P < 0.01 for each). In the MTX-BLPD group, EBV(+) patients showed lower median CIMP than EBV(-) patients (2.3 vs. 3.2); they also had significantly lower hypermethylation incidence in four apoptosis-related genes, especially death-associated protein kinase (14 vs. 55 %), higher incidence of massive tumor necrosis (86 vs. 27 %), and lower BCL2 protein expression (19 vs. 86 %) than did the control DLBCL group (P < 0.01 for all). In all clinical stages, EBV(+) MTX-BLPD patients had better prognoses than the EBV(-) MTX-BLPD (P = 0.011), non-MTX-BLPD (P = 0.002), and control DLBCL groups (P = 0.015). MTX-BLPD patients without hypermethylated RAS-associated domain family-1A (RASSF1A) or O (6) -methyl guanine-DNA methyltransferase (MGMT) had significantly better prognosis than those with hypermethylation of those genes (P = 0.033). We conclude that in RA patients with MTX-BLPD, EBV infection is associated with a lower incidence of CIMP, apoptosis-related gene hypermethylation, and BCL2 expression, which can induce tumor regression by MTX withdrawal and lead to better prognoses.

Both J, Wu T, Ten Asbroek AL, et al.
Oncogenic Properties of Candidate Oncogenes in Chromosome Region 17p11.2p12 in Human Osteosarcoma.
Cytogenet Genome Res. 2016; 150(1):52-59 [PubMed] Related Publications
Osteosarcomas are primary tumors of bone that most often develop in adolescents. They are characterized by complex genomic changes including amplifications, deletions, and translocations. The chromosome region 17p11.2p12 is frequently amplified in human high grade osteosarcomas (25% of cases), suggesting the presence of one or more oncogenes. In previous studies, we identified 9 candidate oncogenes in this region (GID4, ARGHAP44, LRRC75A-AS1, TOP3A, COPS3, SHMT1, PRPSAP2, PMP22, and RASD1). The aim of the present study was to determine their oncogenic properties. Therefore, we generated osteosarcoma cell lines overexpressing these genes, except for LRRC75A-AS1 and PRPSAP2, and subjected these to functional oncogenic assays. We found that TOP3A, SHMT1, and RASD1 overexpression provided increased proliferation and that ARGHAP44, COPS3, and PMP22 overexpression had a stimulatory effect on migration and invasion of the cells. COPS3 and PMP22 overexpression additionally improved the ability of the cells to form new colonies. No oncogenic effect could be demonstrated for GID4 overexpression. We conclude that the concerted amplification-mediated overexpression of these genes in 17p11.2p12 may contribute to the oncogenic process in malignant osteosarcoma.

Kazmi HR, Chandra A, Kumar S, et al.
A let-7 microRNA binding site polymorphism in the KRAS 3'UTR is associated with increased risk and reduced survival for gallbladder cancer in North Indian population.
J Cancer Res Clin Oncol. 2016; 142(12):2577-2583 [PubMed] Related Publications
PURPOSE: Gallbladder cancer is a lethal malignancy of hepato-biliary system with high incidence in North India, especially along gangetic plain. The let-7 microRNAs play a key role in regulating KRAS expression and a polymorphism in 3' untranslated region (rs61764370, T/G) of KRAS leads to its higher expression. This polymorphism is known to be associated with increased risk and prognosis of various cancers but its association with gallbladder cancer has not been evaluated. To address this research question, we evaluated whether rs61764370 variant is associated with gallbladder cancer susceptibility and clinical outcomes.
METHODS: In present case-control study, we enrolled 541 patients with gallbladder malignancy and 307 controls. Genomic DNA was obtained from peripheral blood and genotyping was performed using Taqman allelic discrimination assay.
RESULTS: Heterozygous (TG) individuals are at a significant higher risk for GBC as compared with wild genotype (TT) (p = 0.007, odds ratio = 2.56, 95 % CI 1.27-5.18). At allelic level, allele G has significant higher risk for GBC as compared with T allele (p = 0.008, odds ratio = 2.5, 95 % CI 1.25-5.01). Survival analysis reveals decrease in overall survival for heterozygous genotype (p < 0.0001, hazard ratio = 3.42, 95 % CI 1.21-4.20). Also, significant decrease in overall survival was observed for patient carrying allele G (p < 0.0001, HR = 2.89, 95 % CI 1.21-4.20) as compared with allele C.
CONCLUSIONS: We conclude that KRAS rs61764370 polymorphism is significantly associated with risk and prognosis of gallbladder malignancy in this endemic belt.

Chahal MS, Ku HT, Zhang Z, et al.
Differential Expression of Ccn4 and Other Genes Between Metastatic and Non-metastatic EL4 Mouse Lymphoma Cells.
Cancer Genomics Proteomics. 2016 11-12; 13(6):437-442 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Previous work characterized variants of the EL4 murine lymphoma cell line. Some are non-metastatic, and others metastatic, in syngenic mice. In addition, metastatic EL4 cells were stably transfected with phospholipase D2 (PLD2), which further enhanced metastasis.
MATERIALS AND METHODS: Microarray analyses of mRNA expression was performed for non-metastatic, metastatic, and PLD2-expressing metastatic EL4 cells.
RESULTS: Many differences were observed between non-metastatic and metastatic cell lines. One of the most striking new findings was up-regulation of mRNA for the matricellular protein WNT1-inducible signaling pathway protein 1 (CCN4) in metastatic cells; increased protein expression was verified by immunoblotting and immunocytochemistry. Other differentially expressed genes included those for reproductive homeobox 5 (Rhox5; increased in metastatic) and cystatin 7 (Cst7; decreased in metastatic). Differences between PLD2-expressing and parental cell lines were limited but included the signaling proteins Ras guanyl releasing protein 1 (RGS18; increased with PLD2) and suppressor of cytokine signaling 2 (SOCS2; decreased with PLD2).
CONCLUSION: The results provide insights into signaling pathways potentially involved in conferring metastatic ability on lymphoma cells.

Sideris M, Moorhead J, Diaz-Cano S, et al.
KRAS Mutant Status, p16 and β-catenin Expression May Predict Local Recurrence in Patients Who Underwent Transanal Endoscopic Microsurgery (TEMS) for Stage I Rectal Cancer.
Anticancer Res. 2016; 36(10):5315-5324 [PubMed] Related Publications
BACKGROUND/AIM: Transanal endoscopic microsurgery (TEMS) is emerging as an alternative treatment for rectal cancer Stage I. There remains a risk of local recurrence. The Aim of the study was to study the effect of biomarkers in local recurrence for Stage I rectal cancer following TEMS plus or minus radiotherapy.
MATERIALS AND METHODS: This is a case control study where we compared 10 early rectal cancers that had recurred, against 19 cases with no recurrence, total 29 patients (age=28.25-86.87, mean age=67.92 years, SD=14.91, Male, N=18, Female, N=11). All patients underwent TEMS for radiological Stage I rectal cancer (yT1N0M0 or yT2N0M0) established with combination of magnetic resonance imaging (MRI) and endorectal ultrasound. We prospectively collected all data on tumour histology, morphological features, as well as follow-up parameters. Molecular analysis was performed to identify their status on BRAF, KRAS, p16 O(6)-methylguanine-DNA methyltransferase (MGMT) and β-catenin.
RESULTS: Out of 29 specimens analyzed, 19 were KRAS wild type (65.9%) and 10 mutant (34.5%). Recurrence of the tumour was noted in 10 cases (34.5%) from which 60% were pT1 (N=6) and 40% pT2 (N=4). There was a statistically significant association between KRAS mutant status and local recurrence (N=6, p=0.037). P16 expression greater than 5% (mean=10.8%, min=0, max=95) is linked with earlier recurrence within 11.70 months (N=7, p=0.004). Membranous β-catenin expression (N=12, 48%) was also related with KRAS mutant status (p=0.006) but not with survival (p>0.05). BRAF gene was found to be wild type in all cases tested (N=23).
CONCLUSION: KRAS/p16/β-catenin could be used as a combined biomarker for prediction of local recurrence and stratification of the risk for further surgery.

Watarai H, Okada M, Kuramoto K, et al.
Impact of H3K27 Demethylase Inhibitor GSKJ4 on NSCLC Cells Alone and in Combination with Metformin.
Anticancer Res. 2016; 36(11):6083-6092 [PubMed] Related Publications
BACKGROUND: GSKJ4, an H3K27 demethylase inhibitor, reportedly exhibits antitumor activity against specific cancers harboring genetic alterations in genes encoding chromatin modulators. However, its potential as an anticancer agent against human cancers not associated with such genetic alterations, including non-small cell lung cancer (NSCLC), remains unknown.
MATERIALS AND METHODS: The effect of GSKJ4 on the growth of three NSCLC cell lines and normal lung fibroblasts was investigated using the WST-8, dye exclusion, and colony formation assays.
RESULTS: GSKJ4, alone and in combination with an anti-diabetic drug metformin, induced cell death and inhibited the growth of NSCLC cell lines efficiently at concentrations non-toxic to normal cells, irrespective of their genetic backgrounds (mutations in the KRAS, TP53 and EGFR genes) and also of their resistance to cisplatin and paclitaxel.
CONCLUSION: GSKJ4, being a promising anticancer agent for NSCLC, may be effective against a wider spectrum of cancers than previously thought.

Li C, Chen L, Zhao Y, et al.
Altered expression of miRNAs in the uterus from a letrozole-induced rat PCOS model.
Gene. 2017; 598:20-26 [PubMed] Related Publications
Polycystic ovary syndrome (PCOS) causes female subfertility with ovarian disorders and may be associated with increased rate of early-pregnancy failure. Rat PCOS models were established using letrozole to understand the uterine pathogenesis of PCOS. The differential expression of microRNAs (miRNAs) was observed in rat uterus with PCOS. After estrous cycles were disrupted, significantly abnormal ovarian morphology and hormone level were observed in rats with PCOS. A total of 148 miRNAs differentially expressed were identified in the uterus from the letrozole-induced rat model compared with the control. These miRNAs included 111 upregulated miRNAs and 37 downregulated miRNAs. The differential expression of miR-484, miR-375-3p, miR-324-5p, and miR-223-3p was further confirmed by quantitative reverse transcription polymerase chain reaction. Bioinformatic analysis showed that these four miRNAs were predicted to regulate a large number of genes with different functions. Pathway analysis supported that target genes of miRNAs were involved in insulin secretion and signaling pathways, such as wnt, AMPK, PI3K-Akt, and Ras. These data indicated that miRNAs differentially expressed in rat uterus with PCOS may be associated with PCOS pathogenesis in the uterus. Our findings can help clarify the mechanism of uterine defects in PCOS.

Rabi T, Catapano CV
Aphanin, a triterpenoid from Amoora rohituka inhibits K-Ras mutant activity and STAT3 in pancreatic carcinoma cells.
Tumour Biol. 2016; 37(9):12455-12464 [PubMed] Related Publications
Mutations of the K-Ras gene occur in over 90 % of pancreatic carcinomas, and to date, no targeted therapies exist for this genetically defined subset of cancers. STAT3 plays a critical role in KRAS-driven pancreatic tumorigenesis, suggesting its potential as a therapeutic target in this cancer. Therefore, finding novel and potential drugs to inhibit oncogenic K-Ras is a major challenge in cancer therapy. In an attempt to develop novel anti-KRAS mutant chemotherapeutics, we isolated three novel triterpenoids from Amoora rohituka stem and their chemical structures were characterized by extensive (1)H-NMR, (13)C-NMR, Mass, IR spectroscopic studies and chemical transformations. Aphanin (3 alpha-angeloyloxyolean-12-en-28-oic acid) is one of the isolated novel triterpenoid compounds. We found aphanin exhibited antiproliferative effects, caused G0-G1 cell cycle arrest, inhibits K-Ras G12D mutant activity by decreased STAT3, p-STAT3, Akt, p-Akt, cyclin D1 and c-Myc expressions, and induced apoptosis in pancreatic cancer HPAF-II (ΔKRAS (G12D) ) cells. The apoptosis proceeded through depletion of GSH with a concomitant increase in the reactive oxygen species production. The results of our study have important implications for the development of aphanin as potential novel agent for the treatment of K-Ras mutant pancreatic cancer, and STAT3-cMyc-cyclinD1 axis may serve as an important predictive biomarker for the therapeutic efficacy.

Notta F, Chan-Seng-Yue M, Lemire M, et al.
A renewed model of pancreatic cancer evolution based on genomic rearrangement patterns.
Nature. 2016; 538(7625):378-382 [PubMed] Related Publications
Pancreatic cancer, a highly aggressive tumour type with uniformly poor prognosis, exemplifies the classically held view of stepwise cancer development. The current model of tumorigenesis, based on analyses of precursor lesions, termed pancreatic intraepithelial neoplasm (PanINs) lesions, makes two predictions: first, that pancreatic cancer develops through a particular sequence of genetic alterations (KRAS, followed by CDKN2A, then TP53 and SMAD4); and second, that the evolutionary trajectory of pancreatic cancer progression is gradual because each alteration is acquired independently. A shortcoming of this model is that clonally expanded precursor lesions do not always belong to the tumour lineage, indicating that the evolutionary trajectory of the tumour lineage and precursor lesions can be divergent. This prevailing model of tumorigenesis has contributed to the clinical notion that pancreatic cancer evolves slowly and presents at a late stage. However, the propensity for this disease to rapidly metastasize and the inability to improve patient outcomes, despite efforts aimed at early detection, suggest that pancreatic cancer progression is not gradual. Here, using newly developed informatics tools, we tracked changes in DNA copy number and their associated rearrangements in tumour-enriched genomes and found that pancreatic cancer tumorigenesis is neither gradual nor follows the accepted mutation order. Two-thirds of tumours harbour complex rearrangement patterns associated with mitotic errors, consistent with punctuated equilibrium as the principal evolutionary trajectory. In a subset of cases, the consequence of such errors is the simultaneous, rather than sequential, knockout of canonical preneoplastic genetic drivers that are likely to set-off invasive cancer growth. These findings challenge the current progression model of pancreatic cancer and provide insights into the mutational processes that give rise to these aggressive tumours.

Xu Y, Zhu C, Qian W, Zheng M
Comprehensive study of mutational and clinicopathologic characteristics of adenocarcinoma with lepidic pattern in surgical resected lung adenocarcinoma.
J Cancer Res Clin Oncol. 2017; 143(1):181-186 [PubMed] Related Publications
PURPOSE: Although many studies have explored clinicopathologic characteristics and prognosis of lung adenocarcinoma, a few literatures reported the mutational status of lung adenocarcinomas with lepidic pattern and whether there is difference between adenocarcinomas with pure lepidic component and lepidic predominant adenocarcinomas remain unknown.
METHODS: One hundred and thirty-three patients including 92 adenocarcinomas with pure lepidic component and 41 lepidic predominant adenocarcinomas were subjected to the study. All the clinicopathologic data, the follow-up information and the status of gene mutations including EGFR, KRAS, HER2, BRAF, AKT1, ALK, RET and ROS1 were investigated.
RESULTS: Of the 133 lung adenocarcinomas with lepidic pattern, 87.22 % (116/133) were detected harboring mutations in our tested genes, among which 90.52 % (105/116) harbored EGFR mutation. There are three KRAS mutations and two BRAF mutations in our cohort, and we revealed two ALK fusion and one RET fusion. No ROS1 fusion was discovered. There was no significant difference in gene mutations between adenocarcinomas with pure lepidic component and lepidic predominant adenocarcinomas except EGFR mutation (p = 0.039). Lepidic predominant adenocarcinomas seemed to have more EGFR mutation. The post-recurrence survival was significantly prolonged in patients who received TKIs.
CONCLUSIONS: Adenocarcinoma with lepidic pattern is a low-grade lung tumor with favorable prognosis and displays frequent EGFR mutation. Compared with lepidic predominant adenocarcinomas, lung adenocarcinomas with pure lepidic component have a better prognosis. On the basis of these results, we also suggested the application of EGFR-TKIs therapy for EGFR mutation-positive patients after recurrence could achieve prolonged survival.

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