"The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway." (Source: MeSH)
Figure: An overview of major signal transduction pathways
Source: https://en.wikipedia.org/wiki/File:Signal_transduction_pathways.svg (License: CC BY-SA 3.0)
Introduction to Cancer Biology (Part 1): Abnormal Signal Transduction
mechanismsinmedicine.com Educational animation which explains the mechanism of abnormal signal transduction resulting in uncontrolled cell proliferation. This animation also provides an overview of the potential targets of anticancer therapies.
This list of publications is regularly updated (Source: PubMed).
Yu Z, Song YB, Cui Y, Fu AQ Effects of AIF-1 inflammatory factors on the regulation of Proliferation of breast cancer cells. J Biol Regul Homeost Agents. 2019 Jul-Aug; 33(4):1085-1095 [PubMed] Related Publications
The purpose of this study was to explore the effect of Allograft Inflammatory Factor 1 (AIF-1) on the regulation of proliferation of breast cancer cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), cell culture and counting, and mass spectrometry were performed. The biologically active high-purity recombinant protein rhAIF-1 was obtained by optimizing the rhAIF-1 protein purification system, and MDA-MB-231 and MDA-MB-361 breast cancer cell lines were used. After adding to the culture medium, rhAIF-1 was found to promote cell proliferation in dose-dependent and time-dependent manners. The purified protein rhAIF-1 was marked with rhodamine and incubated with the cells. Confocal imaging analysis revealed that the foreign protein was localized in the cytoplasm, and rhAIF-1 was unevenly distributed in the cytoplasm. Although AIF-1 accumulates around the nucleus, it can not enter the nucleus, suggesting that other factors might be involved in the regulation of cell proliferation. In order to find the possible interacting protein of rhAIF-1, protein immunoprecipitation technique and mass spectrometry were employed, and it was indicated that ADAM28m was the possible interacting protein of rhAIF-1. The interaction between rhAIF-1 and ADAM28m was validated by immunoprecipitation along with Western blotting. It was found that rhAIF-1 could precipitate ADAM28m protein by immunoprecipitation. The results indicated that IF-1 participates in the development of breast cancer by interacting with ADAM28m and activating downstream signaling pathways. It was concluded that AIF-1 provides a new idea for the molecular mechanism of breast cancer cell proliferation and acts as a new target for the prevention and treatment of breast cancer in the future.
Xu P, Ianes C, Gärtner F, et al. Structure, regulation, and (patho-)physiological functions of the stress-induced protein kinase CK1 delta (CSNK1D). Gene. 2019; 715:144005 [PubMed] Related Publications
Members of the highly conserved pleiotropic CK1 family of serine/threonine-specific kinases are tightly regulated in the cell and play crucial regulatory roles in multiple cellular processes from protozoa to human. Since their dysregulation as well as mutations within their coding regions contribute to the development of various different pathologies, including cancer and neurodegenerative diseases, they have become interesting new drug targets within the last decade. However, to develop optimized CK1 isoform-specific therapeutics in personalized therapy concepts, a detailed knowledge of the regulation and functions of the different CK1 isoforms, their various splice variants and orthologs is mandatory. In this review we will focus on the stress-induced CK1 isoform delta (CK1δ), thereby addressing its regulation, physiological functions, the consequences of its deregulation for the development and progression of diseases, and its potential as therapeutic drug target.
Song T, Liu JY, Yang JJ NKAP plays an oncogenic function partly through AKT signaling pathway in hepatocellular carcinoma. Neoplasma. 2019; 2019 [PubMed] Related Publications
NF-kB activating protein (NKAP) is a highly conserved protein involved in transcriptional repression, immune cell development, maturation, T cell acquisition of functional competency and maintenance of hematopoiesis. Here we first explore the function of NKAP in hepatocellular carcinoma (HCC). We found that NKAP was highly expressed in HCC tissues and associated with a poor patient survival. CCK8 assay showed that NKAP knockdown significantly decreased cell viability of HuH7 and Hep3B HCC cell lines. Cell invasion, tested by transwell assays, was significantly inhibited by NKAP knockdown in HuH7 and Hep3B cells (P<0.05). Percentage of cell apoptosis was significantly increased by NKAP knockdown in HuH7 cells (6.5% to 12.5%) and in Hep3B cells (8.3% to 27.3%). Furthermore, western blot results indicated that NKAP silence upregulated the expression of pro-apoptotic proteins Bax and Caspase3-P17 while downregulated anti-apoptotic protein Bcl2. Finaly, AKT signaling pathway was evaluated to reveal the underlying mechanism of NKAP in HCC cells. It was suggested that NKAP knockdown decreased the phosphorylation level of AKT and the expression of its downstream members p70S6K and Cyclin D1. Furthermore, we demonstrated that NKAP knockdown also played an oncogenic role in human gastric cancer AGS and MKN45 cells. In conclusion, for the first time our study reveals that NKAP promotes the proliferation and invasion in HCC cell lines at least partly through AKT signaling pathway.
Fasihi A, Soltani BM, Ranjbaran ZS, et al. Hsa-miR-942 fingerprint in colorectal cancer through Wnt signaling pathway. Gene. 2019; 712:143958 [PubMed] Related Publications
The Wnt signaling pathway has been identified for its function in carcinogenesis and embryonic development. It is known to play a vital role in the initiation and development of colorectal cancer (CRC). Therefore, it is of great importance for CRC research to illuminate the mechanisms which regulate Wnt pathway activity. Here, we intended to examine the effect of hsa-miR-942 (miR-942) on the Wnt signaling activity, cell cycle progression, and its expression in CRC tissues. RT-qPCR results indicated that miR-942 is significantly upregulated in colorectal cancer. Then, overexpression of miR-942 promoted, whereas its inhibition decreased the Wnt signaling activity, detected by RT-qPCR and Top/Fop flash assay. Inhibition of Wnt signaling by using PNU-74654 or IWP-2 small molecules indicated that miR-942 applies its effect to the β-catenin degradation complex level. Then, RT-qPCR and dual luciferase assay showed that miR-942 upregulated Wnt signaling through direct targeting of APC, which is a tumor suppressor in Wnt signaling pathway. Furthermore, the western blotting analysis indicated that β.catenin, as a main member of Wnt signaling pathway is upregulated following the overexpression of miR-942. Finally, miR-942 overexpression resulted in cell cycle progression in SW480 cells. Taken together, our findings established an oncogenic role for miR-942 in CRC and indicated that this miRNA might be a crucial target for CRC therapy.
Sollfrank L, Lettmaier S, Erdmann M, Uslu U Panniculitis Under Successful Targeted Inhibition of the MAPK/ERK Signaling Pathway in a Patient With BRAF V600E-mutated Spindle Cell Oncocytoma of the Pituitary Gland. Anticancer Res. 2019; 39(7):3955-3959 [PubMed] Related Publications
BACKGROUND: Spindle cell oncocytoma (SCO) is a rare non-neuroendocrine neoplasm of the pituitary gland. In general, surgical excision and radiation therapy is performed. However, local recurrences are frequently seen, requiring repeated surgical and radio-oncological interventions. Thus, mutational analysis of the tumor and targeted therapy may represent a valuable therapy option in these patients. CASE REPORT: A 38-year-old female patient with past medical history of 6 surgeries (two transsphenoidal and four transcranial), radiation therapy, and chemoradiation therapy due to several recurrences of a SCO, presented for follow-up imaging. MRI of the brain showed growth of a tumor in the right parasellar region consistent with a new local recurrence, which due to its size and location was considered to be not resectable. Molecular analysis of a previously surgically removed tumor showed a BRAF V600E mutation and thus, combined targeted inhibition of the MAPK/ERK signaling pathway using a BRAF inhibitor and a MEK inhibitor was started. Due to drug-induced panniculitis, MEK inhibitor had to be stopped and BRAF inhibitor only was continued, which was well tolerated by the patient. Subsequent imaging revealed tumor regression already four weeks after therapy initiation and no disease progression has been observed to date. CONCLUSION: A SCO patient with BRAF V600E mutation was successfully treated using targeted inhibition of the MAPK/ERK signaling pathway. Under therapy, tumor regression was observed and the patient has been free of progressive disease for more than two years now. Thus, mutational analysis and targeted inhibition may offer an effective treatment option for SCO patients, while potential side-effects to this therapy, like observed in our case, can occur and needs to be adequately treated.
Liu Y, Kwon T, Kim JS, et al. Peroxiredoxin V Reduces β-Lapachone-induced Apoptosis of Colon Cancer Cells. Anticancer Res. 2019; 39(7):3677-3686 [PubMed] Related Publications
BACKGROUND/AIM: Peroxiredoxin (Prx) V has been known as an antioxidant enzyme which scavenges intracellular reactive oxygen species (ROS). Also, Prx V has been shown to mediate cell apoptosis in various cancers. However, the mechanism of Prx V-induced apoptosis in colon cancer cells remains unknown. Thus, in this study we analyzed the effects of Prx V in β-lapachone-induced apoptosis in SW480 human colon cancer cells. MATERIALS AND METHODS: β-lapachone-induced apoptosis was analyzed by the MTT assay, western blotting, fluorescence microscopy, Annexin V staining and flow cytometry. RESULTS: Overexpression of Prx V, significantly decreased β-lapachone-induced cellular apoptosis and Prx V silencing increased β-lapachone-induced cellular apoptosis via modulating ROS scavenging activity compared to mock SW480 cells. In addition, to further explore the mechanism of Prx V regulated β-lapachone-induced SW480 cells apoptosis, the Wnt/β-catenin signaling was studied. The Wnt/ β-catenin signaling pathway was found to be induced by β-lapachone. CONCLUSION: Prx V regulates SW480 cell apoptosis via scavenging ROS cellular levels and mediating the Wnt/β-catenin signaling pathway, which was induced by β-lapachone.
Xu F, Song Y, Guo A Anti-Apoptotic Effects of Docosahexaenoic Acid in IL-1β-Induced Human Chondrosarcoma Cell Death through Involvement of the MAPK Signaling Pathway. Cytogenet Genome Res. 2019; 158(1):17-24 [PubMed] Related Publications
Osteoarthritis (OA) is a degenerative disease characterized by progressive articular cartilage destruction and joint marginal osteophyte formation with different degrees of synovitis. Docosahexaenoic acid (DHA) is an unsaturated fatty acid with anti-inflammatory, antioxidant, and antiapoptotic functions. In this study, the human chondrosarcoma cell line SW1353 was cultured in vitro, and an OA cell model was constructed with inflammatory factor IL-1β stimulation. After cells were treated with DHA, cell apoptosis was measured. Western blot assay was used to detect protein expression of apoptosis-related factors (Bax, Bcl-2, and cleaved caspase-3) and mitogen-activated protein kinase (MAPK) signaling pathway family members, including extracellular signal-regulated kinase (ERK), c-JUN N-terminal kinase (JNK), and p38 MAPK. Our results show that IL-1β promotes the apoptosis of SW1353 cells, increases the expression of Bax and cleaved caspase-3, and activates the MAPK signaling pathway. In contrast, DHA inhibits the expression of IL-1β, inhibits IL-1β-induced cell apoptosis, and has a certain inhibitory effect on the activation of the MAPK signaling pathway. When the MAPK signaling pathway is inhibited by its inhibitors, the effects of DHA on SW1353 cells are weakened. Thus, DHA enhances the apoptosis of SW1353 cells through the MAPK signaling pathway.
Zhou X, Yan L, Bu XL, et al. Arotinoid trometamol inhibits arsenic trioxide-stimulated keratinocyte proliferation via the Wnt, Shh, and bone morphogenetic protein signaling pathways. J Biol Regul Homeost Agents. 2019 May-Jun; 33(3):731-743 [PubMed] Related Publications
Arsenic acts as a human carcinogen and contributes to skin cancer via mechanisms that remain largely unknown. Recent evidence implicates the perturbation of Wnt, Shh and BMP signals as a potential mechanism. We initiated studies to examine gene expression changes in these signaling pathways. Meanwhile, the antagonistic effect of retinoic acid was explored. In this study, HaCaT and NHEK cells were treated with arsenic trioxide (As2O3) alone or in combination with arotinoid trometamol (retinoic acid receptor agonist). Flow cytometric analysis, PCR array and Western blot were used to determine the potential mechanism and signaling pathways associated with arsenic carcinogenesis. The results showed that low concentration As2O3 could stimulate keratinocyte proliferation, and arotinoid trometamol inhibited the process via regulating the expression of about 20 genes. These genes included components of Wnt signaling (CSNK1A1L, CTNNB1, SFRP1, Wnt10B, Wnt11, Wnt16, Wnt5A, Wnt8A), Shh signaling (C6orf138, HHIP, PTCHD1) and BMP signaling pathway (BMP2, BMP7). The changes of some differentially expressed genes of these signaling pathways in As2O3 treatment group were counteracted by the subsequent arotinoid trometamol treatment. Our data suggest that dysregulation and cross-talk of Wnt, Shh and BMP signals play great roles in the process of arsenic-induced carcinogenesis, which could be antagonized by arotinoid trometamol.
Sharapov MG, Novoselov VI Catalytic and Signaling Role of Peroxiredoxins in Carcinogenesis. Biochemistry (Mosc). 2019; 84(2):79-100 [PubMed] Related Publications
Cancer cells experience strong oxidative stress caused by disorders in cell metabolism and action of external factors. For survival, cancer cells have developed a highly efficient system of antioxidant defense, some of the most important elements of which are peroxiredoxins (Prxs). Prxs are an evolutionarily ancient family of selenium-independent peroxidases that reduce a wide range of organic and inorganic hydroperoxides in the cell and the extracellular space. In addition, some Prxs exhibit chaperone and phospholipase activities. Prxs play an important role in the maintenance of the cell redox homeostasis; they prevent oxidation and aggregation of regulatory proteins, thereby affecting many cell signaling pathways. Prxs are involved in the regulation of cell growth, differentiation, and apoptosis. Due to their versatility and wide representation in all tissues and organs, Prxs participate in the development/suppression of many pathological conditions, among which cancer occupies a special place. This review focuses on the role of Prxs in the development of various forms of cancer. Understanding molecular mechanisms of Prx involvement in these processes will allow to develop new approaches to the prevention and treatment of cancer.
Ou J, Guan D, Yang Y Non-contact co-culture with human vascular endothelial cells promotes epithelial-to-mesenchymal transition of cervical cancer SiHa cells by activating the NOTCH1/LOX/SNAIL pathway. Cell Mol Biol Lett. 2019; 24:39 [PubMed] Free Access to Full ArticleRelated Publications
Background: The aim of this study was to investigate the effect of human umbilical vein endothelial cells on epithelial-to-mesenchymal transition of the cervical cancer cell line SiHa by studying the Notch1/lysyl oxidase (LOX)/SNAIL1 pathway. Methods: Monocultures of SiHa cells, SiHa cells containing a control sequence, and Results: Compared with monocultured SiHa cells, co-cultured SiHa cells showed a significant increase in their invasiveness and expression levels of vimentin, as well as of NOTCH 1, LOX, and SNAIL1, whereas their expression of E-cadherin was significantly reduced and protein activities of MMP-2 and MMP-9 were increased. Compared with SiHa, mono- and co-cultured Conclusion: Co-culture with human umbilical vein endothelial cells promoted the epithelial-to-mesenchymal transition of SiHa cells by activating the NOTCH1/LOX/SNAIL1 pathway in SiHa cells, which enhanced their invasive and metastatic capacities. The results of this study may provide a new perspective on cervical cancer metastasis and a theoretical basis for clinical treatment.
Background: Exploration of the genes with abnormal expression during the development of breast cancer is essential to provide a deeper understanding of the mechanisms involved. Transcriptome sequencing and bioinformatics analysis of invasive ductal carcinoma and paracancerous tissues from the same patient were performed to identify the key genes and signaling pathways related to breast cancer development. Methods: Samples of breast tumor tissue and paracancerous breast tissue were obtained from 6 patients. Sequencing used the Illumina HiSeq platform. All. Only perfectly matched clean reads were mapped to the reference genome database, further analyzed and annotated based on the reference genome information. Differentially expressed genes (DEGs) were identified using the DESeq R package (1.10.1) and DEGSeq R package (1.12.0). Using KOBAS software to execute the KEGG bioinformatics analyses, enriched signaling pathways of DEGs involved in the occurrence of breast cancer were determined. Subsequently, quantitative real time PCR was used to verify the accuracy of the expression profile of key DEGs from the RNA-seq result and to explore the expression patterns of novel cancer-related genes on 8 different clinical individuals. Results: The transcriptomic sequencing results showed 937 DEGs, including 487 upregulated and 450 downregulated genes in the breast cancer specimens. Further quantitative gene expression analysis was performed and captured 252 DEGs (201 downregulated and 51 upregulated) that showed the same differential expression pattern in all libraries. Finally, 6 upregulated DEGs (CST2, DRP2, CLEC5A, SCD, KIAA1211, DTL) and 6 downregulated DEGs (STAC2, BTNL9, CA4, CD300LG, GPIHBP1 and PIGR), were confirmed in a quantitative real time PCR comparison of breast cancer and paracancerous breast tissues from 8 clinical specimens. KEGG analysis revealed various pathway changes, including 20 upregulated and 21 downregulated gene enrichment pathways. The extracellular matrix-receptor (ECM-receptor) interaction pathway was the most enriched pathway: all genes in this pathway were DEGs, including the THBS family, collagen and fibronectin. These DEGs and the ECM-receptor interaction pathway may perform important roles in breast cancer. Conclusion: Several potential breast cancer-related genes and pathways were captured, including 7 novel upregulated genes and 76 novel downregulated genes that were not found in other studies. These genes are related to cell proliferation, movement and adhesion. They may be important for research into breast cancer mechanisms, particularly CST2 and CA4. A key signaling pathway, the ECM-receptor interaction signal pathway, was also identified as possibly involved in the development of breast cancer.
Ma QY, Li SY, Li XZ, et al. Long non-coding RNA DILC suppresses bladder cancer cells progression. Gene. 2019; 710:193-201 [PubMed] Related Publications
Accumulative researches have demonstrated the critical functions of long non-coding RNAs (lncRNAs) in the progression of malignant tumors, including bladder cancer (BC). Our previous studies showed that lnc-DILC was an important tumor suppressor gene in both liver cancer and colorectal cancer. However, the role of lnc-DILC in BC remains to be elucidated. In the present study, we for first found that lnc-DILC was downregulated in human bladder cancer tissues. Lnc-DILC overexpression suppressed the proliferation, metastasis and expansion of bladder cancer stem cells (CSCs). Mechanically, lnc-DILC suppressed BC cells progression via STAT3 pathway. Special STAT3 inhibitor S3I-201 diminished the discrepancy of growth, metastasis and self-renewal ability between lnc-DILC-overexpression BC cells and their control cells, which further confirmed that STAT3 was acquired for lnc-DILC-disrupted BC cell growth, metastasis and self-renewal. Taken together, our results suggest that lnc-DILC is a novel bladder tumor suppressor and indicate that lnc-DILC inhibits BC progression via inactivating STAT3 signaling.
Centrosomes control cell motility, polarity and migration that is thought to be mediated by their microtubule-organizing capacity. Here we demonstrate that WNT signalling drives a distinct form of non-directional cell motility that requires a key centrosome module, but not microtubules or centrosomes. Upon exosome mobilization of PCP-proteins, we show that DVL2 orchestrates recruitment of a CEP192-PLK4/AURKB complex to the cell cortex where PLK4/AURKB act redundantly to drive protrusive activity and cell motility. This is mediated by coordination of formin-dependent actin remodelling through displacement of cortically localized DAAM1 for DAAM2. Furthermore, abnormal expression of PLK4, AURKB and DAAM1 is associated with poor outcomes in breast and bladder cancers. Thus, a centrosomal module plays an atypical function in WNT signalling and actin nucleation that is critical for cancer cell motility and is associated with more aggressive cancers. These studies have broad implications in how contextual signalling controls distinct modes of cell migration.
Saha T, Makar S, Swetha R, et al. Estrogen signaling: An emanating therapeutic target for breast cancer treatment. Eur J Med Chem. 2019; 177:116-143 [PubMed] Related Publications
Breast cancer, a most common malignancy in women, was known to be associated with steroid hormone estrogen. The discovery of estrogen receptor (ER) gave us not only a powerful predictive and prognostic marker, but also an efficient target for the treatment of hormone-dependent breast cancer with various estrogen ligands. ER consists of two subtypes i.e. ERα and ERβ, that are mostly G-protein-coupled receptors and activated by estrogen, specially 17β-estradiol. The activation is followed by translocation into the nucleus and binding with DNA to modulate activities of different genes. ERs can manage synthesis of RNA through genomic actions without directly binding to DNA. Receptors are tethered by protein-protein interactions to a transcription factor complex to communicate with DNA. Estrogens also exhibit nongenomic actions, a characteristic feature of steroid hormones, which are so rapid to be considered by the activation of RNA and translation. These are habitually related to stimulation of different protein kinase cascades. Majority of post-menopausal breast cancer is estrogen dependent, mostly potent biological estrogen (E2) for continuous growth and proliferation. Estrogen helps in regulating the differentiation and proliferation of normal breast epithelial cells. In this review we have investigated the important role of ER in development and progression of breast cancer, which is complicated by receptor's interaction with co-regulatory proteins, cross-talk with other signal transduction pathways and development of treatment strategies viz. selective estrogen receptor modulators (SERMs), selective estrogen receptor down regulators (SERDs), aromatase and sulphatase inhibitors.
Wang S, Wu Y, Xu Y, Tang X miR-10b promoted melanoma progression through Wnt/β-catenin pathway by repressing ITCH expression. Gene. 2019; 710:39-47 [PubMed] Related Publications
Dysregulation of microRNAs (miRNAs) have been reported to contribute to malignant progression in melanoma. However, the roles and mechanisms of several miRNAs in melanoma remain poorly understood. In our study, we showed that miR-10b was significantly up-regulated in melanoma tissues and cell lines, and was associated with overall survival of melanoma patients. Inhibition of miR-10b dramatically suppressed melanoma cell proliferation, migration and invasion in vitro and inhibited tumor growth in vivo. Moreover, we defined ITCH as a direct and functional downstream target of miR-10b, and showed that there was an inverse correlation between the expression of ITCH and miR-10b on melanoma tissues. Down-regulation of ITCH partially attenuated the inhibitory effects of miR-10b inhibition on melanoma cell proliferation, migration and invasion. Furthermore，we found that miR-10b exerted its effects on melanoma by regulating the Wnt/β-catenin pathway. Taken together, our results demonstrated that miR-10b was an important epigenetic modifier, promoting melanoma progression through regulating ITCH/Wnt/β-catenin pathway. These results offer a new strategy for epigenetic cancer therapy.
Cortes JE, Gutzmer R, Kieran MW, Solomon JA Hedgehog signaling inhibitors in solid and hematological cancers. Cancer Treat Rev. 2019; 76:41-50 [PubMed] Related Publications
BACKGROUND: The hedgehog signaling pathway is normally tightly regulated. Mutations in hedgehog pathway components may lead to abnormal activation. Aberrantly activated hedgehog signaling plays a major role in the development of solid and hematological cancer. In recent years, inhibitors have been developed that attenuate hedgehog signaling; 2 have been approved for use in basal cell carcinoma (BCC), while others are under development or in clinical trials. The aim of this review is to provide an overview of known hedgehog inhibitors (HHIs) and their potential for the treatment of hematological cancers and solid tumors beyond BCC. DESIGN: Published literature was searched to identify articles relating to HHIs in noncutaneous cancer. Both preclinical and clinical research articles were included. In addition, relevant clinical trial results were identified from www.clinicaltrials.gov. Information on the pharmacology of HHIs is also included. RESULTS: HHIs show activity in a variety of solid and hematological cancers. In preclinical studies, HHIs demonstrated efficacy in pancreatic cancer, rhabdomyosarcoma, breast cancer, and acute myeloid leukemia (AML). In clinical studies, HHIs showed activity in medulloblastoma, as well as prostate, pancreatic, and hematological cancers. Current clinical trials testing the efficacy of HHIs are underway for prostate, pancreatic, and breast cancers, as well as multiple myeloma and AML. CONCLUSIONS: As clinical trial results become available, it will be possible to discern which additional tumor types are suited to HHI mono- or combination therapy with other anticancer agents. The latter strategy may be useful for delaying or overcoming drug resistance.
The tumor microenvironment is associated with various tumor progressions, including cancer metastasis, immunosuppression, and tumor sustained growth. Tumor-associated macrophages (TAMs) are considered an indispensable component of the tumor microenvironment, participating in the progression of tumor microenvironment remodeling and creating various compounds to regulate tumor activities. This study aims to observe enriched TAMs in tumor tissues during bladder cancer development, which markedly facilitated the proliferation of bladder cancer cells and promoted tumor growth in vivo. We determined that TAMs regulate tumor sustained growth by secreting type I collagen, which can activate the prosurvival integrin α2β1/PI3K/AKT signaling pathway. Furthermore, traditional chemotherapeutic drugs combined with integrin α2β1 inhibitor showed intensive anticancer effects, revealing an innovative approach in clinical bladder cancer treatment.
Patients with advanced colorectal cancer often are treated with systemic cytotoxic therapy using fluorouracil (5-FU), oxaliplatin, irinotecan, and FOLFOX or FOLFIRI combination protocols. Additionally, signaling pathways that are active in colorectal cancer can be therapeutically targeted. Herein, we examined whether chemotherapy impacts on WNT, MAPK and NOTCH signaling pathways in xenograft models of colon cancer. Furthermore, we tested whether combining chemotherapy with MAPK and NOTCH inhibition has superior therapeutic effects. We show that colon cancer cells with high WNT, MAPK and NOTCH activity are variably affected but generally persist in xenograft tumors under different chemotherapeutic regimens, indicating limited effects of cytotoxic therapy on oncogenic signaling pathways. Although these results provided a rationale to additionally target pathway activity, we found no significant increase in therapy response when combining MAPK and NOTCH inhibition with fluorouracil chemotherapy. We attribute this finding to a decrease in tumor cell proliferation upon MAPK and NOTCH inhibition, resulting in reduced effectiveness of cytotoxic treatment. Therapeutic benefits of combining chemotherapy with targeting of oncogenic signaling pathways must therefore be critically evaluated for patients with colorectal cancer.
Hyaluronic acid synthase 2 (HAS2) is suggested to play a critical role in malignancy and is abnormally expressed in many carcinomas. However, its role in colorectal cancer (CRC) malignancy and specific signaling mechanisms remain obscure. Here, we report that HAS2 was markedly increased in both CRC tissue and malignant CRC cell lines. Depletion of HAS2 in HCT116 and DLD1 cells, which express high levels of HAS2, critically increased sensitivity of radiation/oxaliplatin-mediated apoptotic cell death. Moreover, downregulation of HAS2 suppressed migration, invasion and metastasis in nude mice. Conversely, ectopic overexpression of HAS2 in SW480 cells, which express low levels of HAS2, showed the opposite effect. Notably, HAS2 loss- and gain-of-function experiments revealed that it regulates CRC malignancy through TGF-β expression and SMAD2/Snail downstream components. Collectively, our findings suggest that HAS2 contributes to malignant phenotypes of CRC, at least partly, through activation of the TGF-β signaling pathway, and shed light on the novel mechanisms behind the constitutive activation of HAS2 signaling in CRC, thereby highlighting its potential as a therapeutic target.
In colorectal cancer (CRC), aberrant Wnt signalling is essential for tumorigenesis and maintenance of cancer stem cells. However, how other oncogenic pathways converge on Wnt signalling to modulate stem cell homeostasis in CRC currently remains poorly understood. Using large-scale compound screens in CRC, we identify MEK1/2 inhibitors as potent activators of Wnt/β-catenin signalling. Targeting MEK increases Wnt activity in different CRC cell lines and murine intestine in vivo. Truncating mutations of APC generated by CRISPR/Cas9 strongly synergize with MEK inhibitors in enhancing Wnt responses in isogenic CRC models. Mechanistically, we demonstrate that MEK inhibition induces a rapid downregulation of AXIN1. Using patient-derived CRC organoids, we show that MEK inhibition leads to increased Wnt activity, elevated LGR5 levels and enrichment of gene signatures associated with stemness and cancer relapse. Our study demonstrates that clinically used MEK inhibitors inadvertently induce stem cell plasticity, revealing an unknown side effect of RAS pathway inhibition.
Shi G, Lv C, Yang Z, et al. TRIM31 promotes proliferation, invasion and migration of glioma cells through Akt signaling pathway. Neoplasma. 2019; 2019 [PubMed] Related Publications
This study is intended to investigate the role of Tripartite Motif (TRIM) 31 in glioma. Immunohistochemistry and Western blot analysis showed that TRIM31 was overexpressed in high-grade glioma tissues. Univariate survival analysis indicated that high expression of TRIM31 was related to short survival time of glioma patients. Multivariate survival analysis demonstrated that TRIM31 was an independent prognostic factor for glioma patients. In addition, through the experiments on glioma cell lines, we found that after silencing or overexpressing TRIM31 expression, the proliferation, invasion and migration of glioma cells could be downregulated or upregulated through Akt signaling pathway. In short, our study suggests that TRIM31 may be an effective target for glioma intervention.
Gastric cancer (GC) is a common cause of cancer-related death worldwide. As a result of the lack of reliable diagnostic or prognostic biomarkers for GC, patient prognosis is still poor. Therefore, there is an urgent need for studies examining the underlying pathogenesis of GC in order to find effective biomarkers. LRRN1 (leucine-rich repeat neuronal protein-1) is a type I transmembrane protein that plays an important role in the process of nerve development and regeneration. However, its role in cancer, especially in GC, remains unclear. In the present study, we found that LRRN1 expression is upregulated in GC tissues and that high LRRN1 expression is associated with poor prognosis. siRNA and shRNA-mediated knockdowns of LRRN1 expression promoted GC cell apoptosis and activation of the Fas/FasL pathway. LRRN1 knockdown also resulted in upregulation of JUN, a subunit of the transcription factor AP-1 (activator protein-1). This suggests that LRRN1 suppresses GC cell apoptosis by downregulating AP-1, resulting in inhibition of the Fas/FasL pathway. These results confirm that LRRN1 plays a significant role in GC pathogenesis. Moreover, LRRN1 may be a potential prognostic biomarker and therapeutic target for GC.
Advanced metastatic melanoma is a malignant tumor for which there is currently no effective treatment due to resistance development. Ginsenoside Rg3, a saponin component extracted from ginseng roots, has been shown to reduce melanoma cell proliferation by decreasing histone deacetylase 3 and increasing p53 acetylation. The availability of data on the role of Rg3 in melanoma is currently extremely limited. The aim of the present study was to further investigate the effects of Rg3 on B16 melanoma cells and the underlying molecular events. The findings demonstrated that Rg3 suppressed the proliferation and DNA synthesis of B16 cells. Rg3 exposure induced tumor cell cycle arrest at the S phase and reduced the expression of proliferating cell nuclear antigen (PCNA). Rg3 treatment also decreased metastasis of B16 cells in vitro and in vivo. The results indicated that this reduction was due to downregulation of matrix metalloproteinase (MMP)‑2 and MMP‑9. Moreover, Rg3 inhibited melanoma‑induced angiogenesis, most likely by downregulating vascular endothelial growth factor (VEGF) in B16 cells. Rg3 exposure decreased the expression of VEGF in B16 cells and the VEGF downregulation further suppressed angiogenesis by attenuating the proliferation and migration of vascular endothelial cells. Finally, the western blotting data demonstrated that Rg3 reduced the expression of extracellular signal‑regulated kinase (ERK) and protein kinase B (Akt) in vitro and in vivo. This result indicated that the antimelanoma effects of Rg3 may be mediated through suppression of ERK and Akt signaling. Further research is required to assess the value of Rg3 as a novel therapeutic strategy for melanoma in the clinical setting.
Huang L, Huang Z, Lin W, et al. Salidroside suppresses the growth and invasion of human osteosarcoma cell lines MG63 and U2OS in vitro by inhibiting the JAK2/STAT3 signaling pathway. Int J Oncol. 2019; 54(6):1969-1980 [PubMed] Free Access to Full ArticleRelated Publications
Previous research has reported that salidroside exerts antitumor properties on numerous types of tumor cells; however, its effect on osteosarcoma cells remains unknown. The present study aimed to investigate the effects of salidroside on the viability, apoptosis and invasion of osteosarcoma cells in vitro, and determine the underlying mechanism of action. The results of an MTT revealed that salidroside suppressed the viability of osteosarcoma cells (MG63 and U2OS cells) in a time‑ and concentration‑dependent manner. The results of cell morphological analysis (profile observations and Hoechst 33258 staining) and the detection of apoptosis by flow cytometry further indicated that the decrease in osteosarcoma cell viability induced by salidroside was associated with cell apoptosis. Western blot analysis not only confirmed these results but also suggested that salidroside induced the apoptosis of osteosarcoma cells by activating the caspase‑9‑dependent apoptotic pathway. In addition, we reported that salidroside induced G0/G1 phase arrest and suppressed the invasion of osteosarcoma cells, as measured by flow cytometric cell cycle analysis and a Transwell invasion assay, respectively. Western blot analysis confirmed the aforementioned results. Furthermore, our findings demonstrated that salidroside induced the apoptosis, G0/G1 phase arrest and suppressed the invasion of osteosarcoma cells by inhibiting the janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway, as determined by western blot analysis. In summary, the findings of the present study suggested that salidroside may inhibit the progression of osteosarcoma by suppressing the growth and invasion of osteosarcoma cells. Furthermore, the investigations into the underlying mechanism demonstrated that salidroside exerted notable antitumor activity in osteosarcoma cells by inhibiting the JAK2/STAT3 signaling pathway.
Clear cell renal cell carcinoma (ccRCC) is the most common type of renal cell carcinoma and the incidence of this disease is increasing. The present study aimed to investigate the role of homeobox A6 (HOXA6) in the proliferation and apoptosis of ccRCC cells. Analysis of the GSE6344 dataset and immunohistochemistry revealed that the mRNA and protein expression levels of HOXA6 were suppressed in ccRCC tissues. To evaluate the roles of HOXA6 in cell proliferation and apoptosis, ccRCC cell lines (786‑O and 769‑P) were transfected with plasmids expressing HOXA6, empty vector, short hairpin (sh)HOXA6 and non‑targeting shRNA (NC). Cell Counting Kit‑8, colony formation and 5‑ethynyl‑2'‑deoxyuridine staining assays were performed to analyze cell proliferation. In addition, Caspase‑Glo and terminal deoxynucleotidyl transferase dUTP nick end labeling assays were performed to detect apoptosis. Furthermore, the cell cycle and apoptotic rates of 786‑O and 769‑P cells were analyzed by flow cytometry. The results demonstrated that, compared with the empty vector group, the proliferation of 786‑O and 769‑P cells decreased following HOXA6 overexpression; however, compared with the NC group, cell proliferation increased in the shHOXA6 group. The rate of apoptosis of HOXA6‑overexpressing cells was increased compared with the empty vector group, while the rate of apoptosis in the shHOXA6 group was reduced compared with the NC group. In addition, flow cytometry demonstrated that upregulated HOXA6 expression levels could inhibit the cell cycle at the G0/G1 phase. Western blotting revealed that the expression levels of phosphoinositide 3‑kinase (PI3K), phosphorylated (p)‑protein kinase B (Akt), mitogen‑activated protein kinase kinase, p‑extracellular signal‑regulated kinase (ERK) and B‑cell lymphoma 2 (Bcl‑2) were suppressed in cells overexpressing HOXA6; however, the protein expression levels of phosphatase and tensin homolog, Bcl‑2‑associated X protein, cleaved caspase‑3 and cleaved‑poly (ADP‑ribose) polymerase were increased compared with the empty vector group. Opposing results were reported for the shHOXA6 group compared with the NC group. In summary, the results demonstrated that HOXA6 suppresses cell proliferation and promotes apoptosis, which may occur via inhibition of the PI3K/Akt/ERK cascade. These findings indicate the role of HOXA6 in ccRCC; however, the underlying mechanism requires further investigation.
Jiang S, Chang H, Deng S, Fan D Icariin enhances the chemosensitivity of cisplatin‑resistant ovarian cancer cells by suppressing autophagy via activation of the AKT/mTOR/ATG5 pathway. Int J Oncol. 2019; 54(6):1933-1942 [PubMed] Free Access to Full ArticleRelated Publications
Icariin is a flavonoid derived from Epimedium sagittatum, and has a wide range of biological and pharmacological effects; however, little is known regarding its effect on drug‑resistant ovarian cancer and the signal transduction pathways underlying the regulation of apoptosis and autophagy. The present study aimed to investigate the re‑sensitization effects of icariin exerted on an ovarian cancer cell line. Autophagy was analyzed in a SKVCR cell line that had been treated with icariin. We investigated the sensitivity of SKVCR cells to cisplatin, as well as the effects of an autophagy agonist (rapamycin) on autophagy, apoptosis, and the protein kinase B (AKT) signaling pathway. Finally, the mechanism underlying the effects of autophagy‑related (ATG) protein ATG5 overexpression on autophagy, apoptosis and AKT signaling in SKVCR cells were determined. The results revealed that treatment with icariin inhibited cell viability and autophagy, but promoted G0/G1 phase cell cycle arrest and apoptosis as determined by Cell Counting Kit‑8, immunofluorescence and flow cytometry assays, respectively. Icariin reduced the resistance of SKVCR cells to cisplatin in vitro by inducing G1/S cell cycle transition, apoptosis and inhibiting autophagy. Furthermore, enhanced autophagy induced by rapamycin treatment or overexpression of ATG5 partially reversed the effect of icariin on cisplatin resistance and autophagy in SKVCR cells. At the molecular level, rapamycin treatment or overexpression of ATG5 reversed the effects of icariin on the expression of autophagy‑associated proteins, including microtubule‑associated protein 1 light chain 3β, Beclin‑1, ATG5 and p62, and the AKT/mammalian target of rapamycin (mTOR) pathway. Collectively, our results suggested that icariin enhances the chemosensitivity of SKVCR cells by suppressing autophagy via activation of the AKT/mTOR signaling pathway.