IL-6R/STAT3/miR-204 feedback loop contributes to cisplatin resistance of epithelial ovarian cancer cells

Role of TRP channels in carcinogenesis and metastasis: Pathophysiology and regulation by non-coding RNAs

In 2021, David Julius and Ardem Patapoutian received Nobel Prize in Physiology or Medicine for their ground-breaking discoveries in the functional characterization of receptors for temperature and touch. Transient receptor potential (TRP) channels have captivated tremendous appreciation as promising drug targets over the past few years because of central involvement in different cancers. Based on the insights gleaned from decades of high-quality research, basic and clinical scientists have unveiled how Transient receptor potential channels regulated cancer onset and progression. Pioneering studies have sparked renewed interest and researchers have started to scratch the surface of mechanistic role of these channels in wide variety of cancers. In this review we have attempted to provide a summary of most recent updates and advancements made in the biology of these channels in context of cancers. We have partitioned this review into different subsections on the basis of emerging evidence about characteristically distinct role of TRPV (TRPV1, TRPV5), TRPM (TRPM3, TRPM7) and TRPC in cancers. Regulation of TRP channels by non-coding RNAs is also a very exciting area of research which will be helpful in developing a sharper understanding of the multi-step aspects of cancers.

Lactate promoted cisplatin resistance in NSCLC by modulating the m6A modification-mediated FOXO3/MAGI1-IT1/miR-664b-3p/IL-6R axis

BACKGROUND

Cisplatin resistance is one of the major obstacles in non-small cell lung cancer (NSCLC) treatment. Intriguingly, elevated lactate levels were observed in cisplatin-resistant cells, which spurred further investigation into their underlying biological mechanisms.

METHODS

Lactate levels were measured by lactate detection kit. Cisplatin-resistance NSCLC cells were established using progressive concentration of cisplatin. Cell viability, proliferation, and apoptosis were detected by CCK-8, EdU, and flow cytometry, respectively. Cell proliferation in vivo was determined by immunohistochemistry of Ki67 and apoptotic cells were calculated by the TUNEL. MeRIP-PCR was used to measure FOXO3 m6A levels. The interactions of genes were analyzed via RIP, ChIP, Dual-luciferase reporter, and RNA pull-down, respectively.

RESULTS

Elevated lactate levels were observed in both NSCLC patients and cisplatin-resistance cells. Lactate treatment increased cisplatin-resistance cell viability in vitro and promoted tumor growth in vivo. Mechanistically, lactate downregulated FOXO3 by YTHDF2-mediated m6A modification. FOXO3 transcriptionally reduced MAGI1-IT1 expression. FOXO3 overexpression inhibited the lactate-induced promotion of cisplatin resistance in NSCLC, which were reversed by MAGI1-IT1 overexpression. MAGI1-IT1 and IL6R competitively bound miR-664b-3p. FOXO3 overexpression or MAGI1-IT1 knockdown repressed lactate-mediated cisplatin resistance in vivo.

CONCLUSION

Lactate promoted NSCLC cisplatin resistance through regulating FOXO3/MAGI1-IT1/miR-664b-3p/IL6R axis in YTHDF2-mediated m6A modification.

The regulatory mechanisms of oncomiRs in cancer

Cancer development is a complex process that primarily results from the combination of genetic alterations and the dysregulation of major signalling pathways due to interference with the epigenetic machinery. As major epigenetic regulators, miRNAs are central players in the control of many key tumour development factors. These miRNAs have been classified as oncogenic miRNAs (oncomiRs) when they target tumour suppressor genes and tumour suppressor miRNAs (TS miRNAs) when they inhibit oncogene protein expression. Most of the mechanisms that modulate oncomiR expression are linked to transcriptional or posttranscriptional regulation. However, non-transcriptional processes, such as gene amplification, have been described as alternative processes that are responsible for increasing oncomiR expression. The current review summarises the different mechanisms controlling the upregulation of oncomiR expression in cancer cells and the tumour microenvironment (TME). Detailed knowledge of the mechanism underlying the regulation of oncomiR expression in cancer may pave the way for understanding the critical role of oncomiRs in cancer development and progression.

The regulatory relationship between transcription factor STAT3 and noncoding RNA

Signal transducer and activator of transcription 3 (STAT3), as a key node in numerous carcinogenic signaling pathways, is activated in various tumor tissues and plays important roles in tumor formation, metastasis, and drug resistance. STAT3 is considered a potential subtarget for tumor therapy. Noncoding RNA (ncRNA) is a special type of RNA transcript. Transforming from "junk" transcripts into key molecules involved in cell apoptosis, growth, and functional regulation, ncRNA has been proven to be closely related to various epithelial-mesenchymal transition and drug resistance processes in tumor cells over the past few decades. Research on the relationship between transcription factor STAT3 and ncRNAs has attracted increased attention. To date, existing reviews have mainly focused on the regulation by ncRNAs on the transcription factor STAT3; there has been no review of the regulation by STAT3 on ncRNAs. However, understanding the regulation of ncRNAs by STAT3 and its mechanism is important to comprehensively understand the mutual regulatory relationship between STAT3 and ncRNAs. Therefore, in this review, we summarize the regulation by transcription factor STAT3 on long noncoding RNA, microRNA, and circular RNA and its possible mechanisms. In addition, we provide an update on research progress on the regulation of STAT3 by ncRNAs. This will provide a new perspective to comprehensively understand the regulatory relationship between transcription factor STAT3 and ncRNAs, as well as targeting STAT3 or ncRNAs to treat diseases such as tumors.

The potential role of interleukins and interferons in ovarian cancer

Ovarian cancer poses significant challenges and remains a highly lethal disease with limited treatment options. In the context of ovarian cancer, interleukins (ILs) and interferons (IFNs), important cytokines that play crucial roles in regulating the immune system, have emerged as significant factors influencing its development. This article provides a comprehensive review of the involvement of various ILs, including those from the IL-1 family, IL-2 family, IL-6 family, IL-8 family, IL-10 family, and IL-17 family, in ovarian cancer. The focus is on their impact on tumor growth, metastasis, and their role in evading immune responses within the tumor microenvironment. Additionally, the article conducts an in-depth examination of the oncogenic or antitumor roles of each IL in the context of ovarian cancer pathogenesis and progression. Besides, we elucidated the enhancements in the treatment of ovarian cancer through the utilization of type-I IFN and type-II IFN. Recent research has shed light on the intricate mechanisms through which specific ILs and IFNs contribute to the advancement of the disease. By incorporating recent findings, this review also seeks to inspire further investigations into unexplored mechanisms, fostering ongoing research to develop more effective therapeutic strategies for ovarian cancer. Moreover, through an in-depth analysis of IL- and IFN-associated clinical trials, we have highlighted their promising potential of in the treatment of ovarian cancer. These clinical trials serve to reinforce the significant outlook for utilizing ILs and IFNs as therapeutic agents in combating this disease.

Secreted Soluble Factors from Tumor-Activated Mesenchymal Stromal Cells Confer Platinum Chemoresistance to Ovarian Cancer Cells

Ovarian cancer (OC) ranks as the second most common type of gynecological malignancy, has poor survival rates, and is frequently diagnosed at an advanced stage. Platinum-based chemotherapy, such as carboplatin, represents the standard-of-care for OC. However, toxicity and acquired resistance to therapy have proven challenging for the treatment of patients. Chemoresistance, a principal obstacle to durable response in OC patients, is attributed to alterations within the cancer cells, and it can also be mediated by the tumor microenvironment (TME). In this study, we report that conditioned medium (CM) derived from murine and human stromal cells, MS-5 and HS-5, respectively, and tumor-activated HS-5, was active in conferring platinum chemoresistance to OC cells. Moreover, CM derived from differentiated murine pre-adipocyte (3T3-L1), but not undifferentiated pre-adipocyte cells, confers platinum chemoresistance to OC cells. Interestingly, CM derived from tumor-activated HS-5 was more effective in conferring chemoresistance than was CM derived from HS-5 cells. Various OC cells exhibit variable sensitivity to CM activity. Exploring CM content revealed the enrichment of a number of soluble factors in the tumor-activated HS-5, such as soluble uPAR (SuPAR), IL-6, and hepatocyte growth factor (HGF). FDA-approved JAK inhibitors were mildly effective in restoring platinum sensitivity in two of the three OC cell lines in the presence of CM. Moreover, Crizotinib, an ALK and c-MET inhibitor, in combination with platinum, blocked HGF's ability to promote platinum resistance and to restore platinum sensitivity to OC cells. Finally, exposure to 2-hydroxyestardiol (2HE2) was effective in restoring platinum sensitivity to OC cells exposed to CM. Our results showed the significance of soluble factors found in TME in promoting platinum chemoresistance and the potential of combination therapy to restore chemosensitivity to OC cells.

Overcoming Acquired Drug Resistance to Cancer Therapies through Targeted STAT3 Inhibition

Anti-neoplastic agents for cancer treatment utilize many different mechanisms of action and, when combined, can result in potent inhibition of cancer growth. Combination therapies can result in long-term, durable remission or even cure; however, too many times, these anti-neoplastic agents lose their efficacy due to the development of acquired drug resistance (ADR). In this review, we evaluate the scientific and medical literature that elucidate STAT3-mediated mechanisms of resistance to cancer therapeutics. Herein, we have found that at least 24 different anti-neoplastic agents-standard toxic chemotherapeutic agents, targeted kinase inhibitors, anti-hormonal agents, and monoclonal antibodies-that utilize the STAT3 signaling pathway as one mechanism of developing therapeutic resistance. Targeting STAT3, in combination with existing anti-neoplastic agents, may prove to be a successful therapeutic strategy to either prevent or even overcome ADR to standard and novel cancer therapies.

Bacteria and macrophages in the tumor microenvironment

Cancer and microbial infections are significant worldwide health challenges. Numerous studies have demonstrated that bacteria may contribute to the emergence of cancer. In this review, we assemble bacterial species discovered in various cancers to describe their variety and specificity. The relationship between bacteria and macrophages in cancer is also highlighted, and we look for ample proof to establish a biological basis for bacterial-induced macrophage polarization. Finally, we quickly go over the potential roles of metabolites, cytokines, and microRNAs in the regulation of the tumor microenvironment by bacterially activated macrophages. The complexity of bacteria and macrophages in cancer will be revealed as we gain a better understanding of their pathogenic mechanisms, which will lead to new therapeutic approaches for both inflammatory illnesses and cancer.

Paclitaxel-loaded ginsenoside Rg3 liposomes for drug-resistant cancer therapy by dual targeting of the tumor microenvironment and cancer cells

INTRODUCTION

Inherent or acquired resistance to paclitaxel (PTX) is a pivotal challenge for chemotherapy treatment of multidrug-resistant (MDR) breast cancer. Although various targeted drug-delivery systems, including nanoparticles and liposomes, are effective for MDR cancer treatment, their efficacy is restricted by immunosuppressive tumor microenvironment (TME).

METHODS

Ginsenosides Rg3 was used to formulate unique Rg3-based liposomes loaded with PTX to establish Rg3-PTX-LPs, which were prepared by the thin-film hydration method. The stability of the Rg3-PTX-LPs was evaluated by particle size analysis through dynamic light scattering. The active targeting effect of Rg3-based liposomes was examined in an MCF-7/T xenograft model by an in a vivo imaging system. To evaluate the antitumor activity and mechanism of Rg3-PTX-LP, MTT, apoptosis assays, TAM regulation, and TME remodeling were performed in MCF-7/T cells in vitro and in vivo.

RESULTS

Rg3-PTX-LPs could specifically distribute to MCF7/T cancer cells and TME simultaneously, mainly through the recognition of GLUT-1. The drug resistance reversing capability and in vivo antitumor effect of Rg3-PTX-LPs were significantly improved compared with conventional cholesterol liposomes. The TME remodeling mechanisms of Rg3-PTX-LPs included inhibiting IL-6/STAT3/p-STAT3 pathway activation to repolarize protumor M2 macrophages to antitumor M1 phenotype, suppressing myeloid-derived suppressor cells (MDSCs), decreasing tumor-associated fibroblasts (TAFs) and collagen fibers in TME, and promoting apoptosis of tumor cells. Hence, through the dual effects of targeting tumor cells and TME remodeling, Rg3-PTX-LPs achieved a high tumor inhibition rate of 90.3%.

CONCLUSION

Our multifunctional Rg3-based liposome developed in the present study offered a promising strategy for rescuing the drug resistance tumor treatment.

Sensitivity and specificity of microRNA-204, CA125, and CA19.9 as biomarkers for diagnosis of ovarian cancer

Background

Ovarian cancer is usually detected at later stages and no effective screening approach, has been identified. Therefore, sensitive and specific biomarkers for detecting ovarian cancer are urgently needed.

Objective

This study aimed to investigate the efficacy of six biomarkers for the early clinical diagnosis of ovarian cancer.

Subjects & methods

The study included 120 patients (benign ovarian tumors and early and late ovarian carcinoma) and 30 control healthy volunteers. MiRNA-204, CA125, CA19.9, hepcidin, microfibril-associated glycoprotein 2, and ferroportin levels were determined in all patients and control volunteers.

Results

The combined area under the receiver operating characteristic curves for miRNA-204, CA125, and CA19.9 were 0.938, 1.000, and 0.998 for benign tumors and early and late ovarian carcinomas, respectively. The sensitivities of miRNA-204, CA125, and CA19.9 were 98.04%, 100.00%, and 96.19% and the specificities were 58.33%, 62.50%, and 57.78%, respectively.

Conclusion

The positive predictivity of miRNA-204, CA125, and CA19.9 for ovarian cancer is high (59.57%, 58.24%, and 61.67%, respectively). Thus, the combination of these three biomarkers is a good diagnostic tool for ovarian cancer.

A comprehensive survey into the role of microRNAs in ovarian cancer chemoresistance; an updated overview

Ovarian cancer (OC), a frequent malignant tumor that affects women, is one of the leading causes of cancer-related death in this group of individuals. For the treatment of ovarian cancer, systemic chemotherapy with platinum-based drugs or taxanes is the first-line option. However, drug resistance developed over time during chemotherapy medications worsens the situation. Since uncertainty exists for the mechanism of chemotherapy resistance in ovarian cancer, there is a need to investigate and overcome this problem. miRNAs are engaged in various signaling pathways that contribute to the chemotherapeutic resistance of ovarian cancer. In the current study, we have tried to shed light on the mechanisms by which microRNAs contribute to the drug resistance of ovarian cancer and the use of some microRNAs to combat this chemoresistance, leading to the worse outcome of ovarian cancer patients treated with systemic chemotherapeutics.

Identification of circRNA–miRNA–mRNA Regulatory Network and Crucial Signaling Pathway Axis Involved in Tetralogy of Fallot

Tetralogy of Fallot (TOF) is one of the most common cyanotic congenital heart diseases (CHD) worldwide; however, its pathogenesis remains unclear. Recent studies have shown that circular RNAs (circRNAs) act as “sponges” for microRNAs (miRNAs) to compete for endogenous RNA (ceRNA) and play important roles in regulating gene transcription and biological processes. However, the mechanism of ceRNA in TOF remains unclear. To explore the crucial regulatory connections and pathways of TOF, we obtained the human TOF gene, miRNA, and circRNA expression profiling datasets from the Gene Expression Omnibus (GEO) database. After data pretreatment, differentially expressed mRNAs (DEmRNAs), microRNAs (DEmiRNAs), and circRNAs (DEcircRNAs) were identified between the TOF and healthy groups, and a global triple ceRNA regulatory network, including circRNAs, miRNAs, and mRNAs based on the integrated data, was constructed. A functional enrichment analysis was performed on the Metascape website to explore the biological functions of the selected genes. Then, we constructed a protein-protein interaction (PPI) network and identified seven hub genes using the cytoHubba and MCODE plug-ins in the Cytoscape software, including BCL2L11, PIK3R1, SOCS3, OSMR, STAT3, RUNX3, and IL6R. Additionally, a circRNA–miRNA–hub gene subnetwork was established, and its enrichment analysis results indicated that the extrinsic apoptotic signaling pathway, JAK-STAT signaling pathway and PI3K-Akt signaling pathway may be involved in the pathogenesis of TOF. We further identified the hsa_circ_000601/hsa-miR-148a/BCL2L11 axis as a crucial signaling pathway axis from the subnetwork. This study provides a novel regulatory network for the pathogenesis of TOF, revealing the possible molecular mechanisms and crucial regulatory pathways that may provide new strategies for candidate diagnostic biomarkers or potential therapeutic targets for TOF.

The ‘Danse Macabre’—Neutrophils the Interactive Partner Affecting Oral Cancer Outcomes

Over the past few decades, tremendous advances in the prevention, diagnosis, and treatment of cancer have taken place. However for head and neck cancers, including oral cancer, the overall survival rate is below 50% and they remain the seventh most common malignancy worldwide. These cancers are, commonly, aggressive, genetically complex, and difficult to treat and the delay, which often occurs between early recognition of symptoms and diagnosis, and the start of treatment of these cancers, is associated with poor prognosis. Cancer development and progression occurs in concert with alterations in the surrounding stroma, with the immune system being an essential element in this process. Despite neutrophils having major roles in the pathology of many diseases, they were thought to have little impact on cancer development and progression. Recent studies are now challenging this notion and placing neutrophils as central interactive players with other immune and tumor cells in affecting cancer pathology. This review focuses on how neutrophils and their sub-phenotypes, N1, N2, and myeloid-derived suppressor cells, both directly and indirectly affect the anti-tumor and pro-tumor immune responses. Emphasis is placed on what is currently known about the interaction of neutrophils with myeloid innate immune cells (such as dendritic cells and macrophages), innate lymphoid cells, natural killer cells, and fibroblasts to affect the tumor microenvironment and progression of oral cancer. A better understanding of this dialog will allow for improved therapeutics that concurrently target several components of the tumor microenvironment, increasing the possibility of constructive and positive outcomes for oral cancer patients. For this review, PubMed, Web of Science, and Google Scholar were searched for manuscripts using keywords and combinations thereof of “oral cancer, OSCC, neutrophils, TANs, MDSC, immune cells, head and neck cancer, and tumor microenvironment” with a focus on publications from 2018 to 2021.

Combined inhibition of IL‑6 and IL‑8 pathways suppresses ovarian cancer cell viability and migration and tumor growth

Ovarian cancer is the most lethal gynecological cancer type in the United States. The success of current chemotherapies is limited by chemoresistance and side effects. Targeted therapy is a promising future direction for cancer therapy. In the present study, the efficacy of co‑targeting IL‑6 and IL‑8 in human ovarian cancer cells by bazedoxifene (Baze) + SCH527123 (SCH) treatment was examined. ELISA, cell viability, cell proliferation, cell migration, cell invasion, western blotting and peritoneal ovarian tumor mouse model analyses were performed to analyze the expression levels of IL‑6 and IL‑8, tumor growth, tumor migration and invasion, and the possible pathways of human ovarian cancer cell lines (SKOV3, CAOV3 and OVCAR3) and patient‑derived OV75 ovarian cancer cells. Each cell line was treated by monotherapy or combination therapy. The results demonstrated that IL‑6 and IL‑8 were secreted by human ovarian cancer cell lines. Compared with the DMSO control, the combination of IL‑6/glycoprotein 130 inhibitor Baze and IL‑8 inhibitor SCH synergistically inhibited cell viability in ovarian cancer cells. Baze + SCH also inhibited cell migration and invasion, suppressed ovarian tumor growth and inhibited STAT3 and AKT phosphorylation, as well as survivin expression. Therefore, co‑targeting the IL‑6 and IL‑8 signaling pathways may be an effective approach for ovarian cancer treatment.

Gene polymorphisms of Interleukin 6 (−174 G/C) and transforming growth factor β-1(+915 G/C) in ovarian cancer patients

Background

In the study on hand, we investigated the effect of IL-6 (−174 G/C; rs 1800795) and TGF-β1 (+915G/C; rs 1800471) gene polymorphisms on the susceptibility to Ovarian Cancer and their effect on plasma levels. IL-6 (−174 G/C) SNP was analyzed using mutagenically separated polymerase chain reaction (MS-PCR) while TGF-β1 +915G/C (codon 25) SNP was investigated by the sequence-specific primer polymerase chain reaction (SSP-PCR). An enzyme-linked immunosorbent assay (ELISA) was used to quantify IL-6 and TGF-β1 plasma levels in 48 ovarian cancer patients and 48 normal controls.

Results

Regarding IL 6 (−174 G/C), a significant increase in CC and GC+CC genotypes parallel with the C allele was considered as risk factors for ovarian cancer; on the other hand, the G allele was considered as a protective factor for ovarian cancer. TGF-β1 (+915G/C) investigations showed a significant elevation in GC and GC+CC genotypes which can be considered as a risk factor for ovarian cancer. Plasma IL-6 and TGF-β1 were higher in ovarian cancer patients compared with controls. No specific genotype or allele could be responsible for the elevation of TGF-β1 in ovarian cancer patients’ plasma, while the highest significant value for IL6 in subjects carrying GG and CC genotypes in comparison with GC genotype.

Conclusions

This study supports an association of IL6 (−174G/C) and TGF-β1 (+915G/C) gene polymorphisms with the susceptibility to ovarian cancer.

The Non-Coding RNAs Inducing Drug Resistance in Ovarian Cancer: A New Perspective for Understanding Drug Resistance

Ovarian cancer, a common malignant tumor, is one of the primary causes of cancer-related deaths in women. Systemic chemotherapy with platinum-based compounds or taxanes is the first-line treatment for ovarian cancer. However, resistance to these chemotherapeutic drugs worsens the prognosis. The underlying mechanism of chemotherapeutic resistance in ovarian cancer remains unclear. Non-coding RNAs, including long non-coding RNAs, microRNAs, and circular RNAs, have been implicated in the development of drug resistance. Abnormally expressed non-coding RNAs can promote ovarian cancer resistance by inducing apoptosis inhibition, protective autophagy, abnormal tumor cell proliferation, epithelial-mesenchymal transition, abnormal glycolysis, drug efflux, and cancer cell stemness. This review summarizes the role of non-coding RNAs in the development of chemotherapeutic resistance in ovarian cancer, including their mechanisms, targets, and potential signaling pathways. This will facilitate the development of novel chemotherapeutic agents that can target these non-coding RNAs and improve ovarian cancer treatment.

Tumor-Associated Macrophages: Combination of Therapies, the Approach to Improve Cancer Treatment

Macrophages are one of the most important cells of the innate immune system and are known for their ability to engulf and digest foreign substances, including cellular debris and tumor cells. They can convert into tumor-associated macrophages (TAMs) when mature macrophages are recruited into the tumor microenvironment. Their role in cancer progression, metastasis, and therapy failure is of special note. The aim of this review is to understand how the presence of TAMs are both advantageous and disadvantageous in the immune system.

A novel tp53-associated nomogram to predict the overall survival in patients with pancreatic cancer

BACKGROUND

Gene mutations play critical roles in tumorigenesis and cancer development. Our study aimed to screen survival-related mutations and explore a novel gene signature to predict the overall survival in pancreatic cancer.

METHODS

Somatic mutation data from three cohorts were used to identify the common survival-related gene mutation with Kaplan-Meier curves. RNA-sequencing data were used to explore the signature for survival prediction. First, Weighted Gene Co-expression Network Analysis was conducted to identify candidate genes. Then, the ICGC-PACA-CA cohort was applied as the training set and the TCGA-PAAD cohort was used as the external validation set. A TP53-associated signature calculating the risk score of every patient was developed with univariate Cox, least absolute shrinkage and selection operator, and stepwise regression analysis. Kaplan-Meier and receiver operating characteristic curves were plotted to verify the accuracy. The independence of the signature was confirmed by the multivariate Cox regression analysis. Finally, a prognostic nomogram including 359 patients was constructed based on the combined expression data and the risk scores.

RESULTS

TP53 mutation was screened to be the robust and survival-related mutation type, and was associated with immune cell infiltration. Two thousand, four hundred fifty-five genes included in the six modules generated in the WGCNA were screened as candidate survival related TP53-associated genes. A seven-gene signature was constructed: Risk score = (0.1254 × ERRFI1) - (0.1365 × IL6R) - (0.4400 × PPP1R10) - (0.3397 × PTOV1-AS2) + (0.1544 × SCEL) - (0.4412 × SSX2IP) - (0.2231 × TXNL4A). Area Under Curves of 1-, 3-, and 5-year ROC curves were 0.731, 0.808, and 0.873 in the training set and 0.703, 0.677, and 0.737 in the validation set. A prognostic nomogram including 359 patients was constructed and well-calibrated, with the Area Under Curves of 1-, 3-, and 5-year ROC curves as 0.713, 0.753, and 0.823.

CONCLUSIONS

The TP53-associated signature exhibited good prognostic efficacy in predicting the overall survival of PC patients.

High dose acetaminophen inhibits STAT3 and has free radical independent anti-cancer stem cell activity

High-dose acetaminophen (AAP) with delayed rescue using n-acetylcysteine (NAC), the FDA-approved antidote to AAP overdose, has demonstrated promising antitumor efficacy in early phase clinical trials. However, the mechanism of action (MOA) of AAP's anticancer effects remains elusive. Using clinically relevant AAP concentrations, we evaluated cancer stem cell (CSC) phenotype in vitro and in vivo in lung cancer and melanoma cells with diverse driver mutations. Associated mechanisms were also studied. Our results demonstrated that AAP inhibited 3D spheroid formation, self-renewal, and expression of CSC markers when human cancer cells were grown in serum-free CSC media. Similarly, anti-CSC activity was demonstrated in vivo in xenograft models - tumor formation following in vitro treatment and ex-vivo spheroid formation following in vivo treatment. Intriguingly, NAC, used to mitigate AAP's liver toxicity, did not rescue cells from AAP's anti-CSC effects, and AAP failed to reduce glutathione levels in tumor xenograft in contrast to mice liver tissue suggesting nonglutathione-related MOA. In fact, AAP mediates its anti-CSC effect via inhibition of STAT3. AAP directly binds to STAT3 with an affinity in the low micromolar range and a high degree of specificity for STAT3 relative to STAT1. These findings have high immediate translational significance concerning advancing AAP with NAC rescue to selectively rescue hepatotoxicity while inhibiting CSCs. The novel mechanism of selective STAT3 inhibition has implications for developing rational anticancer combinations and better patient selection (predictive biomarkers) for clinical studies and developing novel selective STAT3 inhibitors using AAP's molecular scaffold.

Lipidome-based Targeting of STAT3-driven Breast Cancer Cells Using Poly-l-glutamic Acid-coated Layer-by-Layer Nanoparticles

The oncogenic transcription factor STAT3 is aberrantly activated in 70% of breast cancers, including nearly all triple-negative breast cancers (TNBCs). Because STAT3 is difficult to target directly, we considered whether metabolic changes driven by activated STAT3 could provide a therapeutic opportunity. We found that STAT3 prominently modulated several lipid classes, with most profound effects on N-acyl taurine and arachidonic acid, both of which are involved in plasma membrane remodeling. To exploit these metabolic changes therapeutically, we screened a library of layer-by-layer (LbL) nanoparticles (NPs) differing in the surface layer that modulates interactivity with the cell membrane. We found that poly-l-glutamic acid (PLE)-coated NPs bind to STAT3-transformed breast cancer cells with 50% greater efficiency than to nontransformed cells, and the heightened PLE-NP binding to TNBC cells was attenuated by STAT3 inhibition. This effect was also observed in densely packed three-dimensional breast cancer organoids. As STAT3-transformed cells show greater resistance to cytotoxic agents, we evaluated whether enhanced targeted delivery via PLE-NPs would provide a therapeutic advantage. We found that cisplatin-loaded PLE-NPs induced apoptosis of STAT3-driven cells at lower doses compared with both unencapsulated cisplatin and cisplatin-loaded nontargeted NPs. In addition, because radiation is commonly used in breast cancer treatment, and may alter cellular lipid distribution, we analyzed its effect on PLE-NP-cell binding. Irradiation of cells enhanced the STAT3-targeting properties of PLE-NPs in a dose-dependent manner, suggesting potential synergies between these therapeutic modalities. These findings suggest that cellular lipid changes driven by activated STAT3 may be exploited therapeutically using unique LbL NPs.

LncRNAs and miRNAs participate in determination of sensitivity of cancer cells to cisplatin

Cisplatin is an extensively used chemotherapeutic substance for various types of human malignancies including sarcomas, carcinomas and lymphomas. Yet, the vast application of this drug is hampered by the emergence of chemoresistance in some treated patients. Several mechanisms such as degradation of the membrane transporters by cisplatin have been implicated in the pathogenesis of this event. Recent researches have also indicated the role of long non-coding RNAs (lncRNAs) as well as micoRNAs (miRNAs) in the emergence of resistance to cisplatin in several cancer types. For instance, up-regulation of miR-21 has been associated with resistance to this agent in ovarian cancer, oral squamous cell cancer, gastric malignancy and non-small cell lung cancer (NSCLC). On the other hand, down-regulation of miR-218 has been implicated in emergence of chemoresistance in breast cancer and esophageal squamous cell carcinoma. MALAT1 is implicated in the chemoresistance of bladder cancer cells, NSCLC, gastric cancer and cervical cancer. Most notably, the expression profile of resistance-associated miRNAs and lncRNAs can predict overall survival of cancer patients. Mechanistic assays have revealed that interference with expression of some miRNAs and lncRNAs can reverse the resistance phenotype in cancer cells. In this paper, we review the scientific writings on the role of lncRNAs and miRNAs in the evolution of chemoresistance to cisplatin in cancer cells.

Inflammatory signals induce MUC16 expression in ovarian cancer cells via NF-κB activation

Cancer antigen 125 (CA125), encoded by the mucin 16 cell surface associated (MUC16) gene, has been widely used as a biomarker for ovarian cancer (OC) screening. However, it has yet to be elucidated as to why its levels increase with tumor progression as well as with certain other non-malignant conditions. Based on our knowledge of the inflammatory microenvironment (IME) in OC, HEY cells were treated with several inflammation-associated factors as well as their antagonists, and it was observed that inflammation-associated factors upregulated MUC16 gene expression. Considering the role of nuclear factor (NF)-κB in the inflammatory signaling network and our previous research on OC, chromatin immunoprecipitation was performed, and it was observed that activated NF-κB bound to the MUC16 gene promoter and enhanced its expression, thereby elevating secreted CA125 levels. These findings demonstrated that IME and MUC16 gene expression were associated in OC, partly elucidating the role of IME in tumor progression, explaining the elevated serum CA125 levels in some non-malignant conditions, and confirming IME as a potential target for OC therapy.

Targeting Tumor-Associated Macrophages in Anti-Cancer Therapies: Convincing the Traitors to Do the Right Thing

In the last decade, it has been well-established that tumor-infiltrating myeloid cells fuel not only the process of carcinogenesis through cancer-related inflammation mechanisms, but also tumor progression, invasion, and metastasis. In particular, tumor-associated macrophages (TAMs) are the most abundant leucocyte subset in many cancers and play a major role in the creation of a protective niche for tumor cells. Their ability to generate an immune-suppressive environment is crucial to escape the immune system and to allow the tumor to proliferate and metastasize to distant sites. Conventional therapies, including chemotherapy and radiotherapy, are often not able to limit cancer growth due to the presence of pro-tumoral TAMs; these are also responsible for the failure of novel immunotherapies based on immune-checkpoint inhibition. Several novel therapeutic strategies have been implemented to deplete TAMs; however, more recent approaches aim to use TAMs themselves as weapons to fight cancer. Exploiting their functional plasticity, the reprogramming of TAMs aims to convert immunosuppressive and pro-tumoral macrophages into immunostimulatory and anti-tumor cytotoxic effector cells. This shift eventually leads to the reconstitution of a reactive immune landscape able to destroy the tumor. In this review, we summarize the current knowledge on strategies able to reprogram TAMs with single as well as combination therapies.

MicroRNAs: As Critical Regulators of Tumor- Associated Macrophages

Emerging shreds of evidence suggest that tumor-associated macrophages (TAMs) modulate various hallmarks of cancer during tumor progression. Tumor microenvironment (TME) prime TAMs to execute important roles in cancer development and progression, including angiogenesis, matrix metalloproteinases (MMPs) secretion, and extracellular matrix (ECM) disruption. MicroRNAs (miRNAs) are critical epigenetic regulators, which modulate various functions in diverse types of cells, including macrophages associated with TME. In this review article, we provide an update on miRNAs regulating differentiation, maturation, activation, polarization, and recruitment of macrophages in the TME. Furthermore, extracellular miRNAs are secreted from cancerous cells, which control macrophages phenotypic plasticity to support tumor growth. In return, TAMs also secrete various miRNAs that regulate tumor growth. Herein, we also describe the recent updates on the molecular connection between tumor cells and macrophages. A better understanding of the interaction between miRNAs and TAMs will provide new pharmacological targets to combat cancer.

STAT3, the Challenge for Chemotherapeutic and Radiotherapeutic Efficacy

Chemoradiotherapy is one of the most effective and extensively used strategies for cancer treatment. Signal transducer and activator of transcription 3 (STAT3) regulates vital biological processes, such as cell proliferation and cell growth. It is constitutively activated in various cancers and limits the application of chemoradiotherapy. Accumulating evidence suggests that STAT3 regulates resistance to chemotherapy and radiotherapy and thereby impairs therapeutic efficacy by mediating its feedback loop and several target genes. The alternative splicing product STAT3β is often identified as a dominant-negative regulator, but it enhances sensitivity to chemotherapy and offers a new and challenging approach to reverse therapeutic resistance. We focus here on exploring the role of STAT3 in resistance to receptor tyrosine kinase (RTK) inhibitors and radiotherapy, outlining the potential of targeting STAT3 to overcome chemo(radio)resistance for improving clinical outcomes, and evaluating the importance of STAT3β as a potential therapeutic approach to overcomes chemo(radio)resistance. In this review, we discuss some new insights into the effect of STAT3 and its subtype STAT3β on chemoradiotherapy sensitivity, and we explore how these insights influence clinical treatment and drug development for cancer.

[MiR-204 inhibits invasion and metastasis of breast cancer cells by targeted regulation of HNRNPA2B1]

OBJECTIVE

To investigate the effect of miR-204 on the invasion and metastasis of breast cancer by targeted regulation of HNRNPA2B1.

METHODS

The bioinformatics database was used to obtain data of the expressions of miR-204 in breast cancer patients and the survival rate of the patients. RT-qPCR was used to detect the expression of miR-204 in breast cancer cell lines. The expression vector GV369-miR-204 was used to overexpress miR-204 in MDA-MB-231 cells. Transwell assay was performed to detect the effect of miR-204 on the migration and invasion ability of the breast cancer cells. The key genes (hub genes) of miR-204 were determined by bioinformatics method. A dual luciferase assay was used to analyze the targeting relationship between miR-204 and HNRNPA2B1. The expression of HNRNPA2B1 in MDA-MB-231 cells after miR-204 overexpression was detected by Western blotting, and Transwell assay was used to examine the changes in the cell invasion ability.

RESULTS

The expression of miR-204 was decreased in both breast cancer tissues, and was significantly lower in breast cancer MDA-MB-231 cells than in MCF-10A cells (P < 0.05). The decreased expression of miR-204 was associated with poorer prognosis of breast cancer patients (P < 0.05). Upregulation of miR-204 in MDA-MB-231 cells significantly inhibited the invasion and migration of the cells (P < 0.05). Analysis of the data from the Starbase revealed that the expression of miR-204-5p was negatively correlated with the expression of HNRNPA2B1, and the expression of HNRNPA2B1 was increased in breast cancer patients (P < 0.05) in association with a poorer prognosis of the patients (P < 0.05). Dual luciferase assay demonstrated that miR-204 could bind to HNRNPA2B1 in a target-specific manner. Western blotting and Transwell assay showed that miR-204 significant inhibited the migration and invasion ability of breast cancer cells by targeting HNRNPA2B1 (P < 0.05).

CONCLUSIONS

miR-204 expression is decreased in breast cancer tissues and cells, and its overexpression can inhibit the invasion and metastasis of breast cancer cells by targeted regulation of HNRNPA2B1.

IL-6 induces tumor suppressor protein tyrosine phosphatase receptor type D by inhibiting miR-34a to prevent IL-6 signaling overactivation

Protein tyrosine phosphatase receptor type D (PTPRD) is a tumor suppressor gene that is epigenetically silenced and mutated in several cancers, including breast cancer. Since IL-6/STAT3 signaling is often hyperactivated in breast cancer and STAT3 is a direct PTPRD substrate, we investigated the role of PTPRD in breast cancer and the association between PTPRD and IL-6/STAT3 signaling. We found that PTPRD acts as a tumor suppressor in breast cancer tissues and that high PTPRD expression is positively associated with tumor size, lymph node metastasis, PCNA expression, and patient survival. Moreover, breast cancers with high PTPRD expression tend to exhibit high IL-6 and low phosphorylated-STAT3 expression. IL-6 was found to inhibit miR-34a transcription and induce PTPRD expression in breast cancer and breast epithelial cells, whereas PTPRD was shown to mediate activated STAT3 dephosphorylation and to be a conserved, direct target of miR-34a. IL-6-induced PTPRD upregulation was blocked by miR-34a mimics, whereas experimental PTPRD overexpression suppressed MDA-MB-231 cell migration, invasion, and epithelial to mesenchymal transition, decreased STAT3 phosphorylation, and increased miR-34a transcription. Our findings suggest that PTPRD mediates activated STAT3 dephosphorylation and is induced by the IL-6/STAT3-mediated transcriptional inhibition of miR-34a, thereby establishing a negative feedback loop that inhibits IL-6/STAT3 signaling overactivation.

How microRNAs affect the PD-L1 and its synthetic pathway in cancer

Programmed cell death-ligand 1 (PD-L1) is a glycoprotein that is expressed on the cell surface of both hematopoietic and nonhematopoietic cells. PD-L1 play a role in the immune tolerance and protect self-tissues from immune system attack. Dysfunction of this molecule has been highlighted in the pathogenesis of tumors, autoimmunity, and infectious disorders. MicroRNAs (miRNAs) are endogenous molecules that are classified as small non-coding RNA with approximately 20-22 nucleotides (nt) length. The function of miRNAs is based on complementary interactions with target mRNA via matching completely or incompletely. The result of this function is decay of the target mRNA or preventing mRNA translation. In the past decades, several miRNAs have been discovered which play an important role in the regulation of PD-L1 in various malignancies. In this review, we discuss the effect of miRNAs on PD-L1 expression and consider the effect of miRNAs on the synthetic pathway of PD-L1, especially during cancers.

Downregulation of hsa-microRNA-204-5p and identification of its potential regulatory network in non-small cell lung cancer: RT-qPCR, bioinformatic- and meta-analyses

Background

Pulmonary malignant neoplasms have a high worldwide morbidity and mortality, so the study of these malignancies using microRNAs (miRNAs) has attracted great interest and enthusiasm. The aim of this study was to determine the clinical effect of hsa-microRNA-204-5p (miR-204-5p) and its underlying molecular mechanisms in non-small cell lung cancer (NSCLC).

Methods

Expression of miR-204-5p was investigated by real-time quantitative PCR (RT-qPCR). After data mining from public online repositories, several integrative assessment methods, including receiver operating characteristic (ROC) curves, hazard ratios (HR) with 95% confidence intervals (95% CI), and comprehensive meta-analyses, were conducted to explore the expression and clinical utility of miR-204-5p. The potential objects regulated and controlled by miR-204-5p in the course of NSCLC were identified by estimated target prediction and analysis. The regulatory network of miR-204-5p, with its target genes and transcription factors (TFs), was structured from database evidence and literature references.

Results

The expression of miR-204-5p was downregulated in NSCLC, and the downtrend was related to gender, histological type, vascular invasion, tumor size, clinicopathologic grade and lymph node metastasis (P<0.05). MiR-204-5p was useful in prognosis, but was deemed unsuitable at present as an auxiliary diagnostic or prognostic risk factor for NSCLC due to the lack of statistical significance in meta-analyses and absence of large-scale investigations. Gene enrichment and annotation analyses identified miR-204-5p candidate targets that took part in various genetic activities and biological functions. The predicted TFs, like MAX, MYC, and RUNX1, interfered in regulatory networks involving miR-204-5p and its predicted hub genes, though a modulatory loop or axis of the miRNA-TF-gene that was out of range with shortage in database prediction, experimental proof and literature confirmation.

Conclusions

The frequently observed decrease in miR-204-5p was helpful for NSCLC diagnosis. The estimated target genes and TFs contributed to the anti-oncogene effects of miR-204-5p.

Sphingosine 1-Phosphate Receptor 2 Induces Otoprotective Responses to Cisplatin Treatment

Ototoxicity is a major adverse effect of platinum-based chemotherapeutics and currently, there remains a lack of United States Food and Drug Administration-approved therapies to prevent or treat this problem. In our study, we examined the role of the sphingosine 1-phosphate receptor 2 (S1P₂) in attenuating cisplatin-induced ototoxicity in several different animal models and cell lines. We found that ototoxicity in S1P₂ knockout mice is dependent on reactive oxygen species (ROS) production and that S1P₂ receptor activation with a specific agonist, CYM-5478, significantly attenuates cisplatin-induced defects, including hair cell degeneration in zebrafish and prolonged auditory brainstem response latency in rats. We also evaluated the cytoprotective effect of CYM-5478 across different cell lines and showed that CYM-5478 protects neural-derived cell lines but not breast cancer cells against cisplatin toxicity. We show that this selective protection of CYM-5478 is due to its differential effects on key regulators of apoptosis between neural cells and breast cancer cells. Overall, our study suggests that targeting the S1P₂ receptor represents a promising therapeutic approach for the treatment of cisplatin-induced ototoxicity in cancer patients.

Targeting Transient Receptor Potential Channels by MicroRNAs Drives Tumor Development and Progression

Transient receptor potential (TRP) cation channel superfamily plays important roles in a variety of cellular processes such polymodal cellular sensing, adhesion, polarity, proliferation, differentiation and apoptosis. The expression of TRP channels is strictly regulated and their de-regulation can stimulate cancer development and progression.In human cancers, specific miRNAs are expressed in different tissues, and changes in the regulation of gene expression mediated by specific miRNAs have been associated with carcinogenesis. Several miRNAs/TRP channel pairs have been reported to play an important role in tumor biology. Thus, the TRPM1 gene regulates melanocyte/melanoma behaviour via TRPM1 and microRNA-211 transcripts. Both miR-211 and TRPM1 proteins are regulated through microphthalmia-associated transcription factor (MIFT) and the expression of miR-211 is decreased during melanoma progression. Melanocyte phenotype and melanoma behaviour strictly depend on dual TRPM1 activity, with loss of TRPM1 protein promoting melanoma aggressiveness and miR-211 expression supporting tumour suppressor. TRPM3 plays a major role in the development and progression of human clear cell renal cell carcinoma (ccRCC) with von Hippel-Lindau (VHL) loss. TRPM3, a direct target of miR-204, is enhanced in ccRCC with inactivated or deleted VHL. Loss of VHL inhibits miR-204 expression that lead to increased oncogenic autophagy. Therefore, the understanding of specific TRP channels/miRNAs molecular pathways in distinct tumors could provide a clinical rationale for target therapy in cancer.

miR‑204 inhibits the osteogenic differentiation of mesenchymal stem cells by targeting bone morphogenetic protein 2

Mesenchymal stem cells (MSCs) are used to investigate regeneration and differentiation. MicroRNA-204 (miR-204) in involved in the Runt-related transcription factor 2/alkaline phosphatase/bone morphogenic protein 2 (Runx2/ALP/BMP2) signaling pathway that regulates bone marrow mesenchymal stem cell (BMSC) differentiation; however, the mechanisms underlying the effects of miR-204 are yet to be determined. The aim of the present study was to investigate the effects of miR-204 on BMSC differentiation. BMSCs were derived from rat bone marrow. The expression levels of Runx2, ALP and BMP2 were measured via reverse transcription-quantitative polymerase chain reaction and western blot analyses following transfection of BMSCs with miR-204 agomir or BMP2 expression vector. The ability of the miR-204 gene to directly bind BMP2 mRNA was assessed using dual-luciferase assays. Ossification was measured via alizarin red stain assays. It was observed that the expression levels of Runx2 and ALP increased over time, whereas those of miR-204 decreased; additionally, miR-204 agomir upregulation inhibited the expression of Runx2, ALP and BMP2 in BMSCs. It was revealed that miR-204 directly interacted with BMP2 mRNA, and that transfection with miR-204 agomir suppressed ossification in BMSCs by targeting the BMP2/Runx2/ALP signaling pathway.

Balancing STAT Activity as a Therapeutic Strategy

Driven by dysregulated IL-6 family member cytokine signaling in the tumor microenvironment (TME), aberrant signal transducer and activator of transcription (STAT3) and (STAT5) activation have been identified as key contributors to tumorigenesis. Following transformation, persistent STAT3 activation drives the emergence of mesenchymal/cancer-stem cell (CSC) properties, important determinants of metastatic potential and therapy failure. Moreover, STAT3 signaling within tumor-associated macrophages and neutrophils drives secretion of factors that facilitate metastasis and suppress immune cell function. Persistent STAT5 activation is responsible for cancer cell maintenance through suppression of apoptosis and tumor suppressor signaling. Furthermore, STAT5-mediated CD4+/CD25+ regulatory T cells (T_regs) have been implicated in suppression of immunosurveillance. We discuss these roles for STAT3 and STAT5, and weigh the attractiveness of different modes of targeting each cancer therapy. Moreover, we discuss how anti-tumorigenic STATs, including STAT1 and STAT2, may be leveraged to suppress the pro-tumorigenic functions of STAT3/STAT5 signaling.

Tumor-associated macrophages: an accomplice in solid tumor progression

In many solid tumor types, tumor-associated macrophages (TAMs) are important components of the tumor microenvironment (TME). Moreover, TAMs infiltration is strongly associated with poor survival in solid tumor patients. In this review, we describe the origins of TAMs and their polarization state dictated by the TME. We also specifically focus on the role of TAMs in promoting tumor growth, enhancing cancer cells resistance to chemotherapy and radiotherapy, promoting tumor angiogenesis, inducing tumor migration and invasion and metastasis, activating immunosuppression. In addition, we discuss TAMs can be used as therapeutic targets of solid tumor in clinics. The therapeutic strategies include clearing macrophages and inhibiting the activation of TAMs, promoting macrophage phagocytic activity, limiting monocyte recruitment and other targeted TAMs therapies.

Adipocytes promote ovarian cancer chemoresistance

Ovarian cancer (OvCa), while accounting for only 3% of all women’s cancer, is the fifth leading cause of cancer death among women. One of the most significant obstacles to successful OvCa treatment is chemoresistance. The current lack of understanding of the driving mechanisms underlying chemoresistance hinders the development of effective therapeutics against this obstacle. Adipocytes are key components of the OvCa microenvironment and have been shown to be involved in OvCa cell proliferation, however, little is known about their impact on OvCa chemoresistance. In the current study, we found that adipocytes, of both subcutaneous and visceral origin, secrete factors that enhance the resistance of OvCa cells against chemotherapeutic drugs by activating the Akt pathway. Importantly, we have demonstrated that secreted lipids mediate adipocyte-induced chemoresistance. Through a comprehensive lipidomic analysis, we have identified this chemo-protective lipid mediator as arachidonic acid (AA). AA acts on OvCa cells directly, not through its downstream derivatives such as prostaglandins, to activate Akt and inhibit cisplatin-induced apoptosis. Taken together, our study has identified adipocytes and their secreted AA as important mediators of OvCa chemoresistance. Strategies that block the production of AA from adipocytes or block its anti-apoptotic function may potentially inhibit chemoresistance in OvCa patients.

MicroRNA-204 Potentiates the Sensitivity of Acute Myeloid Leukemia Cells to Arsenic Trioxide

Although arsenic trioxide (ATO) is a well-known antileukemic drug used for acute promyelocytic leukemia treatment, the development of ATO resistance is still a big challenge. We previously reported that microRNA-204 (miR-204) was involved in the regulation of acute myeloid leukemia (AML) cell apoptosis, but its role in chemoresistance is poorly understood. In the present study, we showed that miR-204 was significantly increased in AML cells after ATO treatment. Interestingly, the increased miR-204 level that was negatively correlated with ATO induced the decrease in cell viability and baculoviral inhibition of apoptosis protein repeat-containing 6 (BIRC6) expression. Overexpression of miR-204 potentiated ATO-induced AML cell growth inhibition and apoptosis. Furthermore, miR-204 directly targets to the 3′-UTR of BIRC6. Upregulation of miR-204 decreased BIRC6 luciferase activity and expression, which subsequently enhanced the expression of p53. Restoration of BIRC6 markedly reversed the effect of miR-204 on the regulation of AML cell sensitivity to ATO. Taken together, our study demonstrates that miR-204 decreases ATO chemoresistance in AML cells at least partially via promoting BIRC6/p53-mediated apoptosis. miR-204 represents a novel target of ATO, and upregulation of miR-204 may be a useful strategy to improve the efficacy of ATO in AML treatment.

Long non-coding RNA PCAT6 targets miR-204 to modulate the chemoresistance of colorectal cancer cells to 5-fluorouracil-based treatment through HMGA2 signaling

Colorectal cancer (CRC) is still the third most common cancer in the world with a limited prognosis due to the chemoresistance of CRC cells to 5‐fluorouracil (5‐FU)‐based chemotherapy. In our previous study, we revealed that miR‐204 overexpression could sensitize CRC cell to 5‐FU treatment through targeting HMGA2/PI3K signaling pathway; however, miR‐204 expression in CRC tissues is abnormally downregulated. Long non‐coding RNAs (lncRNAs) dysregulation has been reported in human diseases, including cancer. Also, lncRNA can regulate cancer cell proliferation, invasion, migration, as well as chemoresistance. LncRNA prostate cancer‐associated transcript 6 (PCAT6) acts as an oncogene in many cancers; herein, PCAT6 expression was abnormally upregulated in CRC tissues and cell lines, suggesting its potential role in CRC. Further, we assessed the specific function and mechanism of PCAT6 in CRC. Furthermore, we revealed that PCAT6 knockdown attenuated CRC chemoresistance to 5‐FU through miR‐204/HMGA2/PI3K; miR‐204 inhibition could partially reverse the effect of PCAT6 knockdown. Taken together, we demonstrate that the abnormal PCAT6 overexpression inhibits miR‐204 expression in CRC, thereby promoting HMGA2/PI3K signaling activity, ultimately enhancing the chemoresistance of CRC cells to 5‐FU; PCAT6 represents a promising target for dealing with CRC chemoresistance.

MicroRNA-204-5p suppresses IL6-mediated inflammatory response and chemokine generation in HK-2 renal tubular epithelial cells by targeting IL6R

During the pathogenetic process of varied kidney diseases, renal tubules are the major sites in response to detrimental insults, including pro-inflammatory stimuli. MicroRNA-204-5p (miR-204-5p) can be detected in the renal tubular epithelial cells in the normal kidney; its expression, however, is downregulated in the kidney with pathological changes. This study aimed to investigate the role of miR-204-5p in interleukin 6 (IL6) mediated inflammatory response and chemokine production in HK-2 renal tubular cells. In HK-2 cells, the expression of miR-204-5p was downregulated in response to exogenous pro-inflammatory stimulus, tumor necrosis factor α (TNFα), or IL1β, while that of IL6 receptor α (IL6R) was upregulated. Dual-luciferase results confirmed that miRNA-204-5p directly targeted IL6R. In addition to suppressing IL6R expression, miRNA-204-5p agomir also inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3) in HK-2 cells exposed to exogenous IL6. Further, miRNA-204-5p suppressed the overproduction of pro-inflammatory mediators (cyclooxygenase 2 and prostaglandin E2) and chemokines (C–C motif chemokine ligand 2 and C–X–C motif chemokine ligand 8). The anti-inflammatory effects of miRNA-204-5p were attenuated when IL6R was reexpressed in HK-2 cells. Collectively, our study reveals that miR-204-5p inhibits the inflammation and chemokine generation in renal tubular epithelial cells by modulating the IL6/IL6R axis.

Chemotherapy and Inflammatory Cytokine Signalling in Cancer Cells and the Tumour Microenvironment

Cancer is the result of a cell's acquisition of a variety of biological capabilities or 'hallmarks' as outlined by Hanahan and Weinberg. These include sustained proliferative signalling, the ability to evade growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, and the ability to invade other tissue and metastasize. More recently, the ability to escape immune destruction has been recognized as another important hallmark of tumours. It is suggested that genome instability and inflammation accelerates the acquisition of a variety of the above hallmarks. Inflammation, is a product of the body's response to tissue damage or pathogen invasion. It is required for tissue repair and host defense, but prolonged inflammation can often be the cause for disease. In a cancer patient, it is often unclear whether inflammation plays a protective or deleterious role in disease progression. Chemotherapy drugs can suppress tumour growth but also induce pathways in tumour cells that have been shown experimentally to support tumour progression or, in other cases, encourage an anti-tumour immune response. Thus, with the goal of better understanding the context under which each of these possible outcomes occurs, recent progress exploring chemotherapy-induced inflammatory cytokine production and the effects of cytokines on drug efficacy in the tumour microenvironment will be reviewed. The implications of chemotherapy on host and tumour cytokine pathways and their effect on the treatment of cancer patients will also be discussed.

MiR-204 acts as a potential therapeutic target in acute myeloid leukemia by increasing BIRC6-mediated apoptosis

Acute myeloid leukemia (AML) is one of the most common hematological malignancies all around the world. MicroRNAs have been determined to contribute various cancers initiation and progression, including AML. Although microRNA-204 (miR-204) exerts anti-tumor effects in several kinds of cancers, its function in AML remains unknown. In the present study, we assessed miR-204 expression in AML blood samples and cell lines. We also investigated the effects of miR-204 on cellular function of AML cells and the underlying mechanisms of the action of miR-204. Our results showed that miR-204 expression was significantly downregulated in AML tissues and cell lines. In addition, overexpression of miR-204 induced growth inhibition and apoptosis in AML cells, including AML5, HL-60, Kasumi-1 and U937 cells. Cell cycle analysis further confirmed an augmentation in theapoptotic subG1 population by miR-204 overexpression. Mechanistically, baculoviral inhibition of apoptosis protein repeat containing 6 (BIRC6) was identified as a direct target of miR-204. Enforcing miR-204 expression increased the luciferase activity and expression of BIRC6, as well as p53 and Bax expression. Moreover, restoration of BIRC6 reversed the pro-apoptotic effects of miR-204 overexpression in AML cells. Taken together, this study demonstrates that miR-204 causes AML cell apoptosis by targeting BIRC6, suggesting miR-204 may play an anti-carcinogenic role in AML and function as a novel biomarker and therapeutic target for the treatment of this disease.

TIPE2 sensitizes osteosarcoma cells to cis-platin by down-regulating MDR1 via the TAK1- NF-κB and - AP-1 pathways

TIPE2 participates in multiple types of cancer development. However, its mechanism underlying chemoresistance in osteosarcoma has not been elucidated. Herein, we observed the expression of TIPE2 and MDR1 in cis-platin-resistant osteosarcoma tissues and cell lines. Compared to their matched sensitive cell lines and tissues, TIPE2 was downregulated while MDR1 expression was increased. Further investigation showed that overexpression of TIPE2 effectively inhibited MDR1 expression and greatly sensitized osteosarcoma cells to cis-platin, both in vivo and in vitro. Mechanistically, TIPE2 inhibited the transcription of the MDR1 promoter by interfering with the TAK1-NF-κB and -AP-1 pathways. Overall, our results elucidated for the first time that TIPE2 sensitizes osteosarcoma cells to cis-platin through downregulation of MDR1 and may be a novel target in osteosarcoma therapy.

Ovarian Cancer Immunotherapy: Preclinical Models and Emerging Therapeutics

Immunotherapy has emerged as one of the most promising approaches for ovarian cancer treatment. The tumor microenvironment (TME) is a key factor to consider when stimulating antitumoral responses as it consists largely of tumor promoting immunosuppressive cell types that attenuate antitumor immunity. As our understanding of the determinants of the TME composition grows, we have begun to appreciate the need to address both inter- and intra-tumor heterogeneity, mutation/neoantigen burden, immune landscape, and stromal cell contributions. The majority of immunotherapy studies in ovarian cancer have been performed using the well-characterized murine ID8 ovarian carcinoma model. Numerous other animal models of ovarian cancer exist, but have been underutilized because of their narrow initial characterizations in this context. Here, we describe animal models that may be untapped resources for the immunotherapy field because of their shared genomic alterations and histopathology with human ovarian cancer. We also shed light on the strengths and limitations of these models, and the knowledge gaps that need to be addressed to enhance the utility of preclinical models for testing novel immunotherapeutic approaches.

MircroRNA-139 sensitizes ovarian cancer cell to cisplatin-based chemotherapy through regulation of ATP7A/B

PURPOSE

Ovarian cancer remains a most malignant female cancer nowadays. The acquisition of chemoresistance to common-used cisplatin-based chemotherapy results in a decreased overall patient survival. The present study is aimed to investigate the role and mechanism by which miR-139/ ATPases7A/B axis modulates the chemoresistance of ovarian cancer to cisplatin-based chemotherapy.

METHODS

The expression of miR-139 in cisplatin-sensitive (n = 23) and cisplatin-resistant (n = 14) ovarian cancer tissues and cell lines (CAOV-3 and SNU119) was determined using real-time PCR assays; its effect on ovarian cancer cell chemoresistance to different concentrations of cisplatin was then assessed by measuring the cell viability using MTT assays. Next, miR-139 binding to the 3'UTR of ATP7A/B was confirmed using luciferase reporter gene assays. Finally, the combined effect of miR-139 and ATP7A/B on the chemoresistance of ovarian cancer cell was assessed.

RESULTS

miR-139 expression was down-regulated in cisplatin-resistant ovarian cancer tissues (**P < 0.01) and reduced by cisplatin treatment in ovarian cell lines (*P < 0.05, **P < 0.01); miR-139 could enhance cisplatin-induced suppression on ovarian cancer cell viability, shown as reduced lC50 values; ATP7A and ATP7B protein levesincreased approximately 2 ~ fold-changein cisplatin-resistant cell lines. MiR-139 directly bound to the 3'UTR of ATP7A/B, respectively; miR-139 inhibition increased lC50 values whereas ATP7A/B knockdown reduced lC50 values of CAOV-3 and SNU119 cell lines under cisplatin treatment; the effect of miR-139 inhibition could be partially attenuated by ATP7A/B knockdown.

CONCLUSIONS

MiR-139/ATP7A/B axis can be a reliable biomarker for ovarian cancer diagnosis, and may affect the chemoresistance of ovarian cancer to cisplatin-based chemotherapy; rescuing miR-139 expression thus to inhibit ATP7A/B might contribute to dealing with the chemoresistance of ovarian cancer.

miR-204-5p suppresses hepatocellular cancer proliferation by regulating homeoprotein SIX1 expression

Fewer than 30% of patients with hepatocellular carcinoma (HCC) are eligible to receive curative therapies, and so a better understanding of the molecular mechanisms of HCC is needed to identify potential therapeutic targets. The role of microRNA (miRNA) in modulating tumour progression has been demonstrated, and therapies targeting miRNA appear promising. miR‐204‐5p has been shown to function in numerous types of cancer, but its role in HCC remains unclear. In this study, we found that miR‐204‐5p expression was downregulated in cancerous HCC tissues compared to nontumour tissues. Kaplan–Meier survival curve analysis also showed that low expression of miR‐204‐5p predicted worse outcomes of HCC patients. In addition, miR‐204‐5p expression was significantly lower in HCC cell lines. The function of miR‐204‐5p was also assessed both in vitro and in vivo. We demonstrated that ectopic expression of miR‐204‐5p in HCC cell lines inhibited HCC cell proliferation and clonogenicity using CCK8, BrdU and colony‐forming assays, while the inhibition of miR‐204‐5p enhanced proliferation and clonogenicity. Further in vivo studies in mice further confirmed the proliferation capacity of miR‐204‐5p. We also identified sine oculis homeobox homologue 1 (SIX1) as a direct target of miR‐204‐5p and showed that it was inversely correlated with miR‐204‐5p in both human and mouse HCC tissues. Transfection of miR‐204‐5p mimics in BEL‐7404 cells blocked the cell cycle by inhibiting the expression of cyclin‐D1 and cyclin‐A1, cell cycle‐related factors regulated by SIX1. More importantly, overexpression of the 3′UTR mutant SIX1 but not the wild‐type SIX1 abolished the suppressive effect of miR‐204‐5p, and downregulated SIX1 in BEL‐7402 cells that transfected with miR‐204 inhibitors could partly block the inhibitory effect of miR‐204‐5p on proliferation. Thus, we have demonstrated that miR‐204‐5p suppresses HCC proliferation by directly regulating SIX1 and its downstream factors.

The Immune-microenvironment Confers Chemoresistance of Colorectal Cancer through Macrophage-Derived IL6

Purpose: Tumor-associated macrophages (TAMs) are frequently associated with poor prognosis in human cancers. However, the effects of TAMs in colorectal cancer are contradictory. We therefore investigated the functions, mechanisms, and clinical significance of TAMs in colorectal cancer.Experimental Design: We measured the macrophage infiltration (CD68), P-gp, and Bcl2 expression in colorectal cancer tissues using IHC staining. Coculture of TAMs and colorectal cancer cells both in vitro and in vivo models was used to evaluate the effects of TAMs on colorectal cancer chemoresistance. Cytokine antibody arrays, ELISA, neutralizing antibody, and luciferase reporter assay were performed to uncover the underlying mechanism.Results: TAM infiltration was associated with chemoresistance in patients with colorectal cancer. Colorectal cancer-conditioned macrophages increased colorectal cancer chemoresistance and reduced drug-induced apoptosis by secreting IL6, which could be blocked by a neutralizing anti-IL6 antibody. Macrophage-derived IL6 activated the IL6R/STAT3 pathway in colorectal cancer cells, and activated STAT3 transcriptionally inhibited the tumor suppressor miR-204-5p. Rescue experiment confirmed that miR-204-5p is a functional target mediating the TAM-induced colorectal cancer chemoresistance. miR-155-5p, a key miRNA regulating C/EBPβ, was frequently downregulated in TAMs, resulting in increased C/EBPβ expression. C/EBPβ transcriptionally activated IL6 in TAMs, and TAM-secreted IL6 then induced chemoresistance by activating the IL6R/STAT3/miR-204-5p pathway in colorectal cancer cells.Conclusions: Our data indicate that the maladjusted miR-155-5p/C/EBPβ/IL6 signaling in TAMs could induce chemoresistance in colorectal cancer cells by regulating the IL6R/STAT3/miR-204-5p axis, revealing a new cross-talk between immune cells and tumor cells in colorectal cancer microenvironment. Clin Cancer Res; 23(23); 7375-87. ©2017 AACR.

Infiltrating mast cells enhance benign prostatic hyperplasia through IL-6/STAT3/Cyclin D1 signals

Early evidences have showed that mast cells could infiltrate into benign prostatic hyperplasia (BPH) tissues, but the exact role of mast cells in BPH development remains unclear. In this study, we identified more mast cells existing in human BPH tissues compared with that in the normal prostate. In the in vitro co-culture system, BPH-1 prostate cells promoted activation and migration of mast cells, and mast cells conversely stimulated BPH-1 cells proliferation significantly. Molecular analysis demonstrated that mast cell-derived interleukin 6 (IL-6) could activate STAT3/Cyclin D1 signals in BPH-1 cells. Blocking IL-6 or STAT3 partially reverse the capacity of mast cells to enhance BPH-1 cell proliferation. Our findings suggest that infiltrating mast cells in BPH tissues could promote BPH development via IL-6/STAT3/Cyclin D1 signals. Therefore, targeting infiltrating mast cells may improve the therapeutic effect of BPH.