The miR-31-SOX10 axis regulates tumor growth and chemotherapy resistance of melanoma via PI3K/AKT pathway

Exosomal Non-coding RNAs: A New Approach to Melanoma Diagnosis and Therapeutic Strategy

Malignant melanoma (MM) is a highly aggressive cancer with a poor prognosis. Currently, although a variety of therapies are available for treating melanoma, MM is still a serious threat to the patient's life due to numerous factors, such as the recurrence of tumors, the emergence of drug resistance, and the lack of effective therapeutic agents. Exosomes are biologically active lipid-bilayer extracellular vesicles secreted by diverse cell types that mediate intercellular signal communication. Studies found that exosomes are involved in cancer by carrying multiple bioactive molecules, including non-- coding RNAs (ncRNAs). The ncRNAs have been reported to play an important role in regulating proliferation, angiogenesis, immune regulation, invasion, metastasis, and treatment resistance of tumors. However, the functional role of exosomal ncRNAs in MM remains unknown. Therefore, this review summarizes the current state of melanoma diagnosis, treatment, and the application of exosomal ncRNAs in MM patients, which may provide new insights into the mechanisms involved in melanoma progression and serve as biomarkers for diagnosis and therapeutic targets.

Cutaneous Melanoma: A Review of Multifactorial Pathogenesis, Immunohistochemistry, and Emerging Biomarkers for Early Detection and Management

Cutaneous melanoma (CM) is an increasingly significant public health concern. Due to alarming mortality rates and escalating incidence, it is crucial to understand its etiology and identify emerging biomarkers for improved diagnosis and treatment strategies. This review aims to provide a comprehensive overview of the multifactorial etiology of CM, underscore the importance of early detection, discuss the molecular mechanisms behind melanoma development and progression, and shed light on the role of the potential biomarkers in diagnosis and treatment. The pathogenesis of CM involves a complex interplay of genetic predispositions and environmental exposures, ultraviolet radiation exposure being the predominant environmental risk factor. The emergence of new biomarkers, such as novel immunohistochemical markers, gene mutation analysis, microRNA, and exosome protein expressions, holds promise for improved early detection, and prognostic and personalized therapeutic strategies.

The interplay of common genetic variants NRG1 rs2439302 and RET rs2435357 increases the risk of developing Hirschsprung's disease

Introduction: As a congenital and genetically related disease, many single nucleotide polymorphisms (SNPs) have been reported to be associated with the risk of HSCR. Our previous research showed that SNP rs2439302 (NRG1) interacted with rs2435357 (RET) to increase the risk of HSCR development. However, the underlying molecular mechanism is still not well understood. Methods: SNP rs2439302 (NRG1) and rs2435357 (RET) were genotyped in 470 HSCR cases. The expression of NRG1 and RET was investigated in the colon of HSCR patients. Knockdown of the NRG1 and RET homologs was performed in zebrafish to investigate their synergistic effect on ENS development. The effect of SNP rs2439302 and rs2435357 polymorphism on neuron proliferation, migration, and differentiation were investigated in SHSY-5Y cells and IPSCs. Results: Significant downregulation of NRG1 and RET expression was noticed in the aganglionic segment of HSCR patients and SHSY-5Y cells with rs2439302 GG/rs2435357 TT genotype. NRG1 and RET double mutants caused the most severe reduction in enteric neuron numbers than NRG1 single mutant or RET single mutant in the hindgut of zebrafish. SHSY-5Y cells and IPSCs with rs2439302 GG/rs2435357 TT genotype exhibited a decreased proliferative, migration, and differentiative capacity. CTCF showed a considerably higher binding ability to SNP rs2439302 CC than GG. NRG1 reduction caused a further decrease in SOX10 expression via the PI3K/Akt pathway, which regulates RET expression by directly binding to rs2435357. Discussion: SNP rs2439302 (NRG1) GG increases the risk of developing HSCR by affecting the binding of transcription factor CTCF and interacting with rs2435357 (RET) to regulate RET expression via the PI3K/Akt/SOX10 pathway.

miRNAs as potential game-changers in melanoma: A comprehensive review

Melanoma is the sixth most frequent malignancy. It represents 1.7% of all cancer cases worldwide. Many risk factors are associated with melanoma including ultraviolet radiation skin phenotype, Pigmented Nevi, Pesticides, and genetic and epigenetic factors. Of the main epigenetic factors affecting melanoma are microribonucleic acids (miRNAs). They are short nucleic acid chains that have the potential to prevent the expression of a number of target genes. They could target a number of genes related to melanoma initiation, stemness, angiogenesis, apoptosis, proliferation, and potential resistance to treatment. Additionally, they can control several melanoma signaling pathways, including P53, WNT/-catenin, JAK/STAT, PI3K/AKT/mTOR axis, TGF- β, and EGFR. MiRNAs also play a role in the resistance of melanoma to essential treatment regimens. The stability and abundance of miRNAs might be important factors enhancing the use of miRNAs as markers of prognosis, diagnosis, stemness, survival, and metastasis in melanoma patients.

CTRR-ncRNA: A Knowledgebase for Cancer Therapy Resistance and Recurrence Associated Non-coding RNAs

Cancer therapy resistance and recurrence (CTRR) are the dominant causes of death in cancer patients. Recent studies have indicated that non-coding RNAs (ncRNAs) can not only reverse the resistance to cancer therapy but also are crucial biomarkers for the evaluation and prediction of CTRR. Herein, we developed CTRR-ncRNA, a knowledgebase of CTRR-associated ncRNAs, aiming to provide an accurate and comprehensive resource for research involving the association between CTRR and ncRNAs. Compared to most of the existing cancer databases, CTRR-ncRNA is focused on the clinical characterization of cancers, including cancer subtypes, as well as survival outcomes and responses to personalized therapy of cancer patients. Information pertaining to biomarker ncRNAs has also been documented for the development of personalized CTRR prediction. A user-friendly interface and several functional modules have been incorporated into the database. Based on the preliminary analysis of genotype-phenotype relationships, universal ncRNAs have been found to be potential biomarkers for CTRR. The CTRR-ncRNA is a translation-oriented knowledgebase and it provides a valuable resource for mechanistic investigations and explainable artificial intelligence-based modeling. CTRR-ncRNA is freely available to the public at http://ctrr.bioinf.org.cn/.

MicroRNA-31 Can Positively Regulate the Proliferation, Differentiation and Migration of Keratinocytes

In the past decades, the key roles of most microRNA in dermatosis and skin development have been explored one after another. Among them, microRNA-31 (miR-31) has a prominent role in the regulation of keratinocytes. Numerous studies show that miR-31 can positively regulate the proliferation, differentiation and cell activity of keratinocytes via regulating the NF-κB, RAS/MAPK, Notch signaling pathways, and some cytokines. At present, the interaction between miR-31 and the NF-κB signaling pathway in keratinocytes is a hot research topic. The positive feedback loop formed by miR-31 and NF-κB signaling may bring new ideas for the prevention of psoriasis. The abnormal state of keratinocytes is usually the pathological basis of many skin and immune system diseases. Therefore, strengthening the ability to regulate keratinocytes may be a breakthrough for a variety of diseases. At the same time, miR-31's capacity to accelerate wound healing via positively regulating keratinocytes should be further investigated in the treatment of chronic ulcers and trauma.

Curcumol improves cisplatin sensitivity of human gastric cancer cells through inhibiting PI3K/AKT pathway

BACKGROUND

Curcumol was presented to unleash antitumor effects in a variety of cancers, including gastric cancer. However, the relevance between curcumol and cisplatin resistance in gastric cancer still remains unclear. Therefore, the current research was performed to survey the role of curcumol in cisplatin sensitivity in gastric cancer.

METHODS

First, BGC-823 and BGC-823/DDP cells were incubated with cisplatin for 48 hr and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) analysis was applied to determine the inhibition rate of cell proliferation and the half-maximal inhibitory concentration (IC50 ) of cisplatin. In addition, BGC-823 and BGC-823/DDP cells were treated with curcumol for 48 hr followed with detection of cell viability and apoptosis using MTT and flow cytometry assay, respectively. Moreover, MTT analysis was applied to test the effects of curcumol on cisplatin sensitivity in gastric cancer cells. Lastly, Western blot assay and qRT-PCR analysis were utilized to check the functions of curcumol on PI3K/AKT pathway-related markers.

RESULTS

We found that BGC-823/DDP cells exhibited stronger resistance to cisplatin compared with BGC-823 cells. Furthermore, curcumol evidently reduced cell proliferation and facilitated cell apoptosis in BGC-823/DDP and BGC-823 cells. Moreover, results from MTT assay demonstrated that curcumol notably promoted the suppression effect of cisplatin and decreased the IC50 of cisplatin in BGC-823/DDP and BGC-823 cells. It was also presented that curcumol suppressed the PI3K/AKT pathway dose-dependently in BGC-823/DDP and BGC-823 cells.

CONCLUSION

The findings in the current research demonstrated that curcumol could promote the sensitivity of gastric cancer cells to cisplatin-based chemotherapies via inhibiting the phosphatidylinositol 3-kinase (PI3K)/Protein Kinase B (AKT) pathway.

Circ_0084043 promotes cell proliferation and glycolysis but blocks cell apoptosis in melanoma via circ_0084043-miR-31-KLF3 axis

Melanoma is an aggressive malignant tumor. The crucial role of circular RNAs has been documented in many types of cancer, including melanoma. The objective of this study was to uncover the function of circ_0084043 in the biological process of melanoma and associated mechanism of action. The expression of circ_0084043, miR-31, and Krüppel-like factor 3 (KLF3) was determined by qRT-PCR. Cell proliferation and apoptosis were monitored by the MTT assay and flow cytometry assay, respectively. The progression of glycolysis was evaluated according to the levels of glucose consumption, lactate production, and ATP concentration using appropriate detection kits. The relationship between miR-31 and circ_0084043 or KLF3 was predicted by the bioinformatics tool and ascertained by the dual-luciferase reporter assay. The protein levels of KLF3 and glucose transporter 1 (Glut1) were quantified by western blot. A xenograft model was established to ascertain the role of circ_0084043 in vivo. As a result, circ_0084043 expression was reinforced in melanoma tissues and cells. Circ_0084043 knockdown inhibited cell proliferation, induced cell apoptosis, and restrained glycolysis. MiR-31 was a target of circ_0084043, and miR-31 deficiency reversed the role of circ_0084043 knockdown. KLF3 was targeted by miR-31, and KLF3 upregulation abolished the effects of miR-31 enrichment. Moreover, circ_0084043 knockdown impeded tumor growth in vivo and suppressed the level of Glut1 by modulating miR-31 and KLF3. Circ_0084043 promoted cell proliferation and glycolysis, and blocked apoptosis through the circ_0084043–miR-31–KLF3 regulatory axis in melanoma.

Transcriptional characterization of conjunctival melanoma identifies the cellular tumor microenvironment and prognostic gene signatures

This study characterizes the transcriptome and the cellular tumor microenvironment (TME) of conjunctival melanoma (CM) and identifies prognostically relevant biomarkers. 12 formalin-fixed and paraffin-embedded CM were analyzed by MACE RNA sequencing, including six cases each with good or poor clinical outcome, the latter being defined by local recurrence and/or systemic metastases. Eight healthy conjunctival specimens served as controls. The TME of CM, as determined by bioinformatic cell type enrichment analysis, was characterized by the enrichment of melanocytes, pericytes and especially various immune cell types, such as plasmacytoid dendritic cells, natural killer T cells, B cells and mast cells. Differentially expressed genes between CM and control were mainly involved in inhibition of apoptosis, proteolysis and response to growth factors. POU3F3, BIRC5 and 7 were among the top expressed genes associated with inhibition of apoptosis. 20 genes, among them CENPK, INHA, USP33, CASP3, SNORA73B, AAR2, SNRNP48 and GPN1, were identified as prognostically relevant factors reaching high classification accuracy (area under the curve: 1.0). The present study provides new insights into the TME and the transcriptional profile of CM and additionally identifies new prognostic biomarkers. These results add new diagnostic tools and may lead to new options of targeted therapy for CM.

MicroRNA-31 weakens cisplatin resistance of medulloblastoma cells via NF-κB and PI3K/AKT pathways

BACKGROUND

Medulloblastoma (MB) is a malignant intracranial tumor. Cisplatin is a broad-spectrum antitumor drug. It is important to study the cisplatin resistance of MB cells for the treatment of MB. In this article, we preliminarily studied the cisplatin resistance of microRNA (miR)-31 and the possible mechanism in DAOY and UW228 cells, laying a theoretical foundation for clinical treatment of MB.

METHODS

Following anti-miR-31 and pre-miR-31 transfections, cell viability, BrdU, CyclinD1, and apoptosis levels of DAOY and UW228 cell were detected by CCK8, BrdU, and western blot. Meanwhile, migration, invasion, and western blot assay were respectively used to detect the functions of miR-31 migration and invasion. miR-31 levels were changed by cell transfection and detected by RT-qPCR. Furthermore, the related-proteins of pathways were also detected by western blot.

RESULTS

Anti-miR-31 increased DAOY and UW228 cells viability, BrdU⁺ numbers, and expression of CyclinD1. The migration/invasion rate and expression levels of MMP-9 and vimentin after anti-miR-31 transfection were increased. Furthermore, anti-miR-31 enhanced cells' cisplatin resistance and triggered PI3K/AKT and NF-κB pathways. Pre-miR-31 played opposite roles and promoted the apoptosis.

CONCLUSION

miR-31 regulated cell growth, migration, invasion and cisplatin resistance of MB cells via PI3K/AKT and NF-κB pathways.

Abnormal overexpression of G9a in melanoma cells promotes cancer progression via upregulation of the Notch1 signaling pathway

Malignant melanoma is a type of very dangerous skin cancer. Histone modifiers usually become dysregulated during the process of carcinoma development, thus there is potential for a histone modifier inhibitor as a useful drug for cancer therapy. There is a multitude of evidence regarding the role of G9a, a histone methyltransferase (HMTase), in tumorigenesis. In this study, we first showed that G9a was significantly upregulated in melanoma patients. Using the TCGA database, we found a significantly higher expression of G9a in primary melanoma samples (n = 461) compared to normal skin samples (n = 551). Next, we knocked down G9a in human M14 and A375 melanoma cell lines in vitro via small interfering RNA (siRNA). This resulted in a significant decrease in cell viability, migration and invasion, and an increase in cell apoptosis. UNC0642 is a small molecule inhibitor of G9a that demonstrates minimal cell toxicity and good in vivo pharmacokinetic characteristics. We investigated the role of UNC0642 in melanoma cells, and detected its anti-cancer effects in vitro and in vivo. Next, we treated cells with UNC0642, and observed a significant decrease in cell viability in M14 and A375 cell lines. Furthermore, treatment with UNC0642 resulted in increased apoptosis. In immunocompetent mice bearing A375 engrafts, treatment with UNC0642 inhibited tumor growth. Results of Western blot analysis revealed that administration of UNC0642 or silencing of G9a expression by siRNA reduced Notch1 expression significantly and decreased the level of Hes1 in A375. All in all, the data from our study demonstrates potential of G9a as a therapeutic target in the treatment of melanoma.

The miRNAs Role in Melanoma and in Its Resistance to Therapy

Melanoma is the less common but the most malignant skin cancer. Since the survival rate of melanoma metastasis is about 10–15%, many different studies have been carried out in order to find a more effective treatment. Although the development of target-based therapies and immunotherapeutic strategies has improved chances for patient survival, melanoma treatment still remains a big challenge for oncologists. Here, we collect recent data about the emerging role of melanoma-associated microRNAs (miRNAs) currently available treatments, and their involvement in drug resistance. We also reviewed miRNAs as prognostic factors, because of their chemical stability and resistance to RNase activity, in melanoma progression. Moreover, despite miRNAs being considered small conserved regulators with the limitation of target specificity, we outline the dual role of melanoma-associated miRNAs, as oncogenic and/or tumor suppressive factors, compared to other tumors.

Dissecting Mechanisms of Melanoma Resistance to BRAF and MEK Inhibitors Revealed Genetic and Non-Genetic Patient- and Drug-Specific Alterations and Remarkable Phenotypic Plasticity

The clinical benefit of MAPK pathway inhibition in BRAF-mutant melanoma patients is limited by the development of acquired resistance. Using drug-naïve cell lines derived from tumor specimens, we established a preclinical model of melanoma resistance to vemurafenib or trametinib to provide insight into resistance mechanisms. Dissecting the mechanisms accompanying the development of resistance, we have shown that (i) most of genetic and non-genetic alterations are triggered in a cell line- and/or drug-specific manner; (ii) several changes previously assigned to the development of resistance are induced as the immediate response to the extent measurable at the bulk levels; (iii) reprogramming observed in cross-resistance experiments and growth factor-dependence restricted by the drug presence indicate that phenotypic plasticity of melanoma cells largely contributes to the sustained resistance. Whole-exome sequencing revealed novel genetic alterations, including a frameshift variant of RBMX found exclusively in phospho-AKT^high resistant cell lines. There was no similar pattern of phenotypic alterations among eleven resistant cell lines, including expression/activity of crucial regulators, such as MITF, AXL, SOX, and NGFR, which suggests that patient-to-patient variability is richer and more nuanced than previously described. This diversity should be considered during the development of new strategies to circumvent the acquired resistance to targeted therapies.

miR-31-5p Is a Potential Circulating Biomarker and Therapeutic Target for Oral Cancer

MicroRNAs have been proposed as novel biomarkers for the diagnosis and treatment of many types of cancer. The levels of five candidate microRNAs (miRNAs) (miR-99a-5p, miR-31-5p, miR-138-5p, miR-21-5p, and miR-375-3p) in sera from oral cancer patients and paired tumor and normal tissues were detected by real-time qPCR. The diagnostic power of these miRNAs was analyzed by receiver operating characteristic (ROC) curves. Patient-derived xenograft (PDX) models of oral cancer were established and utilized to verify the potential therapeutic effect of miR-31-5p. Candidate miRNAs were screened from our previous studies and verified in 11 paired oral cancer and adjacent normal tissues. Only serum miR-31-5p levels were significantly different between oral cancer patients and healthy controls and between pre- and postoperative patients. Based on the logistic regression model, this panel of five miRNAs distinguished oral cancer patients from healthy control, with an area under the ROC curve (AUC) of 0.776 (sensitivity = 76.8% and specificity = 73.6%). Furthermore, a miR-31-5p mimic enhanced the proliferation of normal epithelial cells, and antagomiR-31-5p inhibited the proliferation of oral cancer cells in vitro. In vivo, antagomiR-31-5p significantly inhibited tumor growth in oral cancer PDX models. Our findings suggest that circulating miR-31-5p might act as an independent biomarker for oral cancer diagnosis and could serve as a therapeutic target for oral cancer.

The role of SOX family members in solid tumours and metastasis

Cancer is a heavy burden for humans across the world with high morbidity and mortality. Transcription factors including sex determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are thought to be involved in the regulation of specific biological processes. The deregulation of gene expression programs can lead to cancer development. Here, we review the role of the SOX family in breast cancer, prostate cancer, renal cell carcinoma, thyroid cancer, brain tumours, gastrointestinal and lung tumours as well as the entailing therapeutic implications. The SOX family consists of more than 20 members that mediate DNA binding by the HMG domain and have regulatory functions in development, cell-fate decision, and differentiation. SOX2, SOX4, SOX5, SOX8, SOX9, and SOX18 are up-regulated in different cancer types and have been found to be associated with poor prognosis, while the up-regulation of SOX11 and SOX30 appears to be favourable for the outcome in other cancer types. SOX2, SOX4, SOX5 and other SOX members are involved in tumorigenesis, e.g. SOX2 is markedly up-regulated in chemotherapy resistant cells. The SoxF family (SOX7, SOX17, SOX18) plays an important role in angio- and lymphangiogenesis, with SOX18 seemingly being an attractive target for anti-angiogenic therapy and the treatment of metastatic disease in cancer. In summary, SOX transcription factors play an important role in cancer progression, including tumorigenesis, changes in the tumour microenvironment, and metastasis. Certain SOX proteins are potential molecular markers for cancer prognosis and putative potential therapeutic targets, but further investigations are required to understand their physiological functions.

Interplay between small and long non-coding RNAs in cutaneous melanoma: a complex jigsaw puzzle with missing pieces

The incidence of cutaneous melanoma (CM) has increased in the past few decades. The biology of melanoma is characterized by a complex interaction between genetic, environmental and phenotypic factors. A greater understanding of the molecular mechanisms that promote melanoma cell growth and dissemination is crucial to improve diagnosis, prognostication, and treatment of CM. Both small and long non-coding RNAs (lncRNAs) have been identified to play a role in melanoma biology; microRNA and lncRNA expression is altered in transformed melanocytes and this in turn has functional effects on cell proliferation, apoptosis, invasion, metastasis, and immune response. Moreover, specific dysregulated ncRNAs were shown to have a diagnostic or prognostic role in melanoma and to drive the establishment of drug resistance. Here, we review the current literature on small and lncRNAs with a role in melanoma, with the aim of putting into some order this complex jigsaw puzzle.