MiR-1294 confers cisplatin resistance in ovarian Cancer cells by targeting IGF1R

Biomarker potential of competing endogenous RNA networks in Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most common condition affecting women of reproductive age globally. PCOS continues to be the largest contributing factor to female infertility despite significant progress in our knowledge of the molecular underpinnings and treatment of the condition. The fact that PCOS is a very diverse condition makes it one of the key reasons why we haven't been able to overcome it. Non-coding RNAs (ncRNAs) are implicated in the development of PCOS, according to growing evidence. However, it is unclear how the complex regulatory relationships between the many ncRNA types contribute to the growth of this malignancy. Competing endogenous RNA (ceRNA), a recently identified mechanism in the RNA world, suggests regulatory interactions between various RNAs, including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), transcribed pseudogenes, and circular RNAs (circRNAs). Recent studies on PCOS have shown that dysregulation of multiple ceRNA networks (ceRNETs) between these ncRNAs plays crucial roles in developing the defining characteristics of PCOS development. And it is believed that such a finding may open a new door for a deeper comprehension of PCOS's unexplored facets. In addition, it may be able to provide fresh biomarkers and effective therapy targets for PCOS. This review will go over the body of information that exists about the primary roles of ceRNETs before highlighting the developing involvement of several newly found ceRNETs in a number of PCOS characteristics.

Prediction of Chemoresistance-How Preclinical Data Could Help to Modify Therapeutic Strategy in High-Grade Serous Ovarian Cancer

High-grade serous ovarian cancer (HGSOC) is one of the most lethal tumors generally and the most fatal cancer of the female genital tract. The approved standard therapy consists of surgical cytoreduction and platinum/taxane-based chemotherapy, and of targeted therapy in selected patients. The main therapeutic problem is chemoresistance of recurrent and metastatic HGSOC tumors which results in low survival in the group of FIGO III/IV. Therefore, the prediction and monitoring of chemoresistance seems to be of utmost importance for the improvement of HGSOC management. This type of cancer has genetic heterogeneity with several subtypes being characterized by diverse gene signatures and disturbed peculiar epigenetic regulation. HGSOC develops and metastasizes preferentially in the specific intraperitoneal environment composed mainly of fibroblasts, adipocytes, and immune cells. Different HGSOC subtypes could be sensitive to distinct sets of drugs. Moreover, primary, metastatic, and recurrent tumors are characterized by an individual biology, and thus diverse drug responsibility. Without a precise identification of the tumor and its microenvironment, effective treatment seems to be elusive. This paper reviews tumor-derived genomic, mutational, cellular, and epigenetic biomarkers of HGSOC drug resistance, as well as tumor microenvironment-derived biomarkers of chemoresistance, and discusses their possible use in the novel complex approach to ovarian cancer therapy and monitoring.

Coding and noncoding RNA profile of human heterotopic ossifications - Risk factors and biomarkers

Heterotopic ossification (HO) means the formation of bone in muscles and soft tissues, such as ligaments or tendons. HO could have a genetic history or develop after a traumatic event, as a result of muscle injury, fractures, burns, surgery, or neurological disorders. Many lines of evidence suggest that the formation of HO is related to the pathological differentiation of stem or progenitor cells present within soft tissues or mobilized from the bone marrow. The cells responsible for the initiation and progression of HO are generally called HO precursor cells. The exact mechanisms behind the development of HO are not fully understood. However, several factors have been identified as potential contributors. For example, local tissue injury and inflammation disturb soft tissue homeostasis. Inflammatory cells release growth factors and cytokines that promote osteogenic or chondrogenic differentiation of HO precursor cells. The bone morphogenetic protein (BMP) is one of the main factors involved in the development of HO. In this study, next-generation sequencing (NGS) and RT-qPCR were performed to analyze the differences in mRNA, miRNA, and lncRNA expression profiles between muscles, control bone samples, and HO samples coming from patients who underwent total hip replacement (THR). As a result, crucial changes in the level of gene expression between HO and healthy tissues were identified. The bioinformatic analysis allowed to describe the processes most severely impacted, as well as genes which level differed the most significantly between HO and control samples. Our analysis showed that the level of transcripts involved in leukocyte migration, differentiation, and activation, as well as markers of chronic inflammatory diseases, that is, miR-148, increased in HO, as compared to muscle. Furthermore, the levels of miR-195 and miR-143, which are involved in angiogenesis, were up-regulated in HO, as compared to bone. Thus, we suggested that inflammation and angiogenesis play an important role in HO formation. Importantly, we noticed that HO is characterized by a higher level of TLR3 expression, compared to muscle and bone. Thus, we suggest that infection may also be a risk factor in HO development. Furthermore, an increased level of transcripts coding proteins involved in osteogenesis and signaling pathways, such as ALPL, SP7, BGLAP, BMP8A, BMP8B, SMPD3 was noticed in HO, as compared to muscles. Interestingly, miR-99b, miR-146, miR-204, and LINC00320 were up-regulated in HO, comparing to muscles and bone. Therefore, we suggested that these molecules could be important biomarkers of HO formation and a potential target for therapies.

HSP90AB1 as the Druggable Target of Maggot Extract Reverses Cisplatin Resistance in Ovarian Cancer

Cisplatin resistance is a crucial factor affecting ovarian cancer patient's survival rate, but the primary mechanism underlying cisplatin resistance in ovarian cancer remains unclear, and this prevents the optimal use of cisplatin therapy. Maggot extract (ME) is used in traditional Chinese medicine for patients with comas and patients with gastric cancer when combined with other drug treatments. In this study, we investigated whether ME enhances the sensitivity of ovarian cancer cells to cisplatin. Two ovarian cancer cells-A2780/CDDP and SKOV3/CDDP-were treated with cisplatin and ME in vitro. SKOV3/CDDP cells that stably expressed luciferase were subcutaneously or intraperitoneally injected into BALB/c nude mice to establish a xenograft model, and this was followed by ME/cisplatin treatment. In the presence of cisplatin, ME treatment effectively suppressed the growth and metastasis of cisplatin-resistant ovarian cancer in vivo and in vitro. RNA-sequencing data showed that HSP90AB1 and IGF1R were markedly increased in A2780/CDDP cells. ME treatment markedly decreased the expression of HSP90AB1 and IGF1R, thereby increasing the expression of the proapoptotic proteins p-p53, BAX, and p-H2AX, while the opposite effects were observed for the antiapoptotic protein BCL2. Inhibition of HSP90 ATPase was more beneficial against ovarian cancer in the presence of ME treatment. In turn, HSP90AB1 overexpression effectively inhibited the effect of ME in promoting the increased expression of apoptotic proteins and DNA damage response proteins in SKOV3/CDDP cells. Inhibition of cisplatin-induced apoptosis and DNA damage by HSP90AB1 overexpression confers chemoresistance in ovarian cancer. ME can enhance the sensitivity of ovarian cancer cells to cisplatin toxicity by inhibiting HSP90AB1/IGF1R interactions, and this might represent a novel target for overcoming cisplatin resistance in ovarian cancer chemotherapy.

Ovarian Cancer—Insights into Platinum Resistance and Overcoming It

Ovarian cancer is the most lethal gynecologic malignancy. Platinum-based chemotherapy is the backbone of treatment for ovarian cancer, and although the majority of patients initially have a platinum-sensitive disease, through multiple recurrences, they will acquire resistance. Platinum-resistant recurrent ovarian cancer has a poor prognosis and few treatment options with limited efficacy. Resistance to platinum compounds is a complex process involving multiple mechanisms pertaining not only to the tumoral cell but also to the tumoral microenvironment. In this review, we discuss the molecular mechanism involved in ovarian cancer cells’ resistance to platinum-based chemotherapy, focusing on the alteration of drug influx and efflux pathways, DNA repair, the dysregulation of epigenetic modulation, and the involvement of the tumoral microenvironment in the acquisition of the platinum-resistant phenotype. Furthermore, we review promising alternative treatment approaches that may improve these patients’ poor prognosis, discussing current strategies, novel combinations, and therapeutic agents.

Exosomes as crucial emerging tools for intercellular communication with therapeutic potential in ovarian cancer

More than two-thirds of epithelial ovarian cancer (EOC) patients are diagnosed at advanced stages due to the lack of sensitive biomarkers. Currently, exosomes are intensively investigated as non-invasive cancer diagnostic markers. Exosomes are nanovesicles released in the extracellular milieu with the potential to modulate recipient cells' behavior. EOC cells release many altered exosomal cargoes that exhibit clinical relevance to tumor progression. Exosomes represent powerful therapeutic tools (drug carriers or vaccines), posing a promising option in clinical practice for curing EOC in the near future. In this review, we highlight the importance of exosomes in cell–cell communication, epithelial–mesenchymal transition (EMT), and their potential to serve as diagnostic and prognostic factors, particularly in EOC.

KLF2-induced circZKSCAN1 potentiates the tumorigenic properties of clear cell renal cell carcinoma by targeting the miR-1294/PIM1 axis

Clear cell renal cell carcinoma (ccRCC) is one of the most common and lethal types of urologic cancer. With low survival rates among patients in advanced stages of disease, and increasing rate of morbidity and mortality worldwide, novel therapeutic targets for ccRCC clinical intervention are necessary. In this study, we investigated the functional role of circZKSCAN1 in ccRCC progression. Our results suggested that circZKSCAN1 was abundantly expressed in ccRCC tumor tissues and cells. CircZKSCAN1 knockdown significantly inhibited cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition of renal cell carcinoma (RCC) cells, whereas potentiated Natural Killer (NK) cell-mediated cytotoxicity against RCC cells in vitro and repressed tumor growth in vivo. Furthermore, we identified a novel circZKSCAN1/miR-1294/PIM1 axis was identified in RCC progression, showing that the expression of circZKSCAN1 expression in RCC cells was transcriptionally regulated by Kruppel-like factor 2. The results of our study may provide new insights for ccRCC basic research.Abbreviations: ccRCC: clear cell renal cell carcinoma; ChIP: chromatin immunoprecipitation; circRNA: circular RNA; EDU: 5-ethynyl-2'-deoxyuridine; EMT: epithelial-mesenchymal transition; FBS: fetal bovine serum; FISH: RNA fluorescent in situ hybridization; KLF2: Kruppel-like factor 2; NC: normal control; NK cell: natural killer cell; NOD/SCID: nonobese severe diabetic/severe combined immunodeficiency; PIM1: Pim-1 proto-oncogene, serine/threonine kinase; RCC: renal cell carcinoma; ZKSCAN1: zinc finger with KRAB and SCAN domains 1.

Silencing of miR-1246 Induces Cell Cycle Arrest and Apoptosis in Cisplatin-Resistant Ovarian Cancer Cells by Promoting ZNF23 Transcription

Ovarian cancer (OC) is the most frequent cause of death among patients with gynecologic malignancies. In recent years, the development of cisplatin (DDP) resistance has become an important reason for the poor prognosis of OC patients. Therefore, it is vital to explore the mechanism of DDP resistance in OC. In this study, microRNA-1246 (miR-1246) expression in OC and DDP-resistant OC cells was determined by RT-qPCR, and chemosensitivity to DDP was assessed by the CCK-8 assay. A dual-luciferase reporter assay was performed to confirm the interaction between miR-1246 and zinc finger 23 (ZNF23), while changes in ZNF23 expression were monitored by RT-qPCR, immunofluorescence, and western blot assays. Moreover, cell proliferation, cycle phase, and apoptosis were determined by EdU staining, flow cytometry, TUNEL staining, and Hoechst staining. Our data showed that miR-1246 was highly expressed in DDP-resistant OVCAR-3 and TOV-112D cells. Functionally, overexpression of miR-1246 markedly enhanced DDP resistance and cell proliferation, and suppressed cell cycle arrest and apoptosis of OC cells. Inhibition of miR-1246 expression significantly attenuated DDP resistance and cell proliferation, and increased cell cycle arrest and apoptosis in DDP-resistant OC cells. Furthermore, ZNF23 was identified as a target gene of miR-1246, and ZNF23 protein expression was notably downregulated in DDP-resistant OC cells. Moreover, overexpression of miR-1246 significantly downregulated the ZNF23 levels in OVCAR-3 and TOV-112D cells, and inhibition of miR-1246 upregulated the ZNF23 levels in the DDP-resistant OVCAR-3 and TOV-112D cells. In conclusion, miR-1246 might be a novel regulator of DDP-resistant OC that functions by regulating ZNF23 expression in DDP-resistant cells, as well as cell proliferation, cell cycle progression, and apoptosis.

Platinum-resistant ovarian cancer: From drug resistance mechanisms to liquid biopsy-based biomarkers for disease management

Resistance to platinum-based chemotherapy is a major clinical challenge in ovarian cancer, contributing to the high mortality-to-incidence ratio. Management of the platinum-resistant disease has been difficult due to diverse underlying molecular mechanisms. Over the past several years, research has revealed several novel molecular targets that are being explored as biomarkers for treatment planning and monitoring of response. The therapeutic landscape of ovarian cancer is also rapidly evolving, and alternative therapies are becoming available for the recurrent platinum-resistant disease. This review provides a snapshot of platinum resistance mechanisms and discusses liquid-based biomarkers and their potential utility in effective management of platinum-resistant ovarian cancer.

MicroRNAs as the critical regulators of Cisplatin resistance in ovarian cancer cells

BACKGROUND

Ovarian cancer (OC) is one of the leading causes of cancer related deaths among women. Due to the asymptomatic tumor progression and lack of efficient screening methods, majority of OC patients are diagnosed in advanced tumor stages. A combination of surgical resection and platinum based-therapy is the common treatment option for advanced OC patients. However, tumor relapse is observed in about 70% of cases due to the treatment failure. Cisplatin is widely used as an efficient first-line treatment option for OC; however cisplatin resistance is observed in a noticeable ratio of cases. Regarding, the severe cisplatin side effects, it is required to clarify the molecular biology of cisplatin resistance to improve the clinical outcomes of OC patients. Cisplatin resistance in OC is associated with abnormal drug transportation, increased detoxification, abnormal apoptosis, and abnormal DNA repair ability. MicroRNAs (miRNAs) are critical factors involved in cell proliferation, apoptosis, and chemo resistance. MiRNAs as non-invasive and more stable factors compared with mRNAs, can be introduced as efficient markers of cisplatin response in OC patients.

MAIN BODY

In present review, we have summarized all of the miRNAs that have been associated with cisplatin resistance in OC. We also categorized the miRNAs based on their targets to clarify their probable molecular mechanisms during cisplatin resistance in ovarian tumor cells.

CONCLUSIONS

It was observed that miRNAs mainly exert their role in cisplatin response through regulation of apoptosis, signaling pathways, and transcription factors in OC cells. This review highlighted the miRNAs as important regulators of cisplatin response in ovarian tumor cells. Moreover, present review paves the way of suggesting a non-invasive panel of prediction markers for cisplatin response among OC patients.

Substrate Stiffness Modulates the Growth, Phenotype, and Chemoresistance of Ovarian Cancer Cells

Mechanical factors in the tumor microenvironment play an important role in response to a variety of cellular activities in cancer cells. Here, we utilized polyacrylamide hydrogels with varying physical parameters simulating tumor and metastatic target tissues to investigate the effect of substrate stiffness on the growth, phenotype, and chemotherapeutic response of ovarian cancer cells (OCCs). We found that increasing the substrate stiffness promoted the proliferation of SKOV-3 cells, an OCC cell line. This proliferation coincided with the nuclear translocation of the oncogene Yes-associated protein. Additionally, we found that substrate softening promoted elements of epithelial-mesenchymal transition (EMT), including mesenchymal cell shape changes, increase in vimentin expression, and decrease in E-cadherin and β-catenin expression. Growing evidence demonstrates that apart from contributing to cancer initiation and progression, EMT can promote chemotherapy resistance in ovarian cancer cells. Furthermore, we evaluated tumor response to standard chemotherapeutic drugs (cisplatin and paclitaxel) and found antiproliferation effects to be directly proportional to the stiffness of the substrate. Nanomechanical studies based on atomic force microscopy (AFM) have revealed that chemosensitivity and chemoresistance are related to cellular mechanical properties. The results of cellular elastic modulus measurements determined by AFM demonstrated that Young's modulus of SKOV-3 cells grown on soft substrates was less than that of cells grown on stiff substrates. Gene expression analysis of SKOV-3 cells showed that mRNA expression can be greatly affected by substrate stiffness. Finally, immunocytochemistry analyses revealed an increase in multidrug resistance proteins, namely, ATP binding cassette subfamily B member 1 and member 4 (ABCB1 and ABCB4), in the cells grown on the soft gel resulting in resistance to chemotherapeutic drugs. In conclusion, our study may help in identification of effective targets for cancer therapy and improve our understanding of the mechanisms of cancer progression and chemoresistance.

CircRNA UBAP2 serves as a sponge of miR-1294 to increase tumorigenesis in hepatocellular carcinoma through regulating c-Myc expression

Circular RNAs (circRNAs) are a class of regulatory RNAs with complex roles in healthy and diseased tissues. However, the oncogenic role of circRNAs in hepatocellular carcinoma (HCC) remains poorly understood, including the mechanisms by which the circular ubiquitin binding associated protein 2 (circUBAP2) contributes to tumorigenesis. We analyzed the expression of circUBAP2 in 20 paired samples of HCC and healthy tissue as well as in seven HCC cell lines via quantitative real-time polymerase chain reaction (qRT-PCR). Functional experiments, such as CCK8 viability assays, colony formation assays, wound healing, transwell assays, and flow cytometry, were conducted to assess the effects of circUBAP2 in vitro. To further elucidate the mechanisms by which circUBAP2 acts, we conducted dual-luciferase assays, western blots, RNA pull-down assays, and rescue experiments. CircUBAP2 was highly upregulated in most HCC tissues and was associated with poor prognosis. HCC patients with high circUBAP2 expression had greater vascular invasion and worse differentiation. Functionally, circUBAP2 overexpression enhanced HCC cell proliferation, migration, and invasion and inhibited apoptosis. Furthermore, we found that circUBAP2 upregulated c-Myc expression by sponging miR-1294, thus contributing to hepatocarcinogenesis. Inhibiting circUBAP2 expression in HCC attenuated the oncogenic effects of c-Myc. These findings suggest that circUBAP2 promotes HCC growth and metastasis. CircUBAP2 may have value as an independent prognostic biomarker or as a new target for the treatment of HCC.

Resistance to platinum-based cancer drugs: a special focus on epigenetic mechanisms

Chemoresistance is a significant clinical challenge, limiting the drug response in cancer. Several mechanisms associated with drug resistance have been characterized, and the role of epigenetics in generating resistance to platinum-based drugs has been clarified. Epigenetic mechanisms such as DNA methylation, histone modification, long noncoding RNA, and microRNA affect the expression of genes implicated in absorption, distribution, metabolism and excretion (ADME) of drugs, and other non-ADME genes that encode enzymes involved in the processes of cell proliferation, DNA repair, apoptosis and signal transduction key in the development of chemoresistance in cancer, specifically in platinum-based drugs. This review summarizes current discoveries in epigenetic regulation implicated in platinum drug resistance in cancer and the main clinical trials based on epigenetic therapy, evaluating their potential synergy with platinum-based drugs.

IGF-1R anti-idiotypic antibody antagonist exhibited anti-ovarian cancer bioactivity and reduced cisplatin resistance

Ovarian cancer is the most deadly gynecological malignant tumor in the world today. Previous studies have shown that insulin-like growth factor-1 receptor (IGF-1R) is closely related to the occurrence and development of ovarian cancer, and ovarian cancer cells endogenously express high IGF-1R. Therefore, IGF-1R could be used as a target for ovarian cancer treatment. In the past, the strategy for preparing IGF-1R antagonists was to use IGF-1R antibody and small-molecule inhibitor. In the current research, we use a new method to prepare IGF-1R antagonists. We prepared a series of IGF-1 internal imaging anti-idiotypic antibodies by anti-idiotypic antibody strategy. After a series of screening and identification, one of the anti-idiotypic antibodies (B003-2A) was selected for further evaluation, and the results showed that B003-2A could not only inhibit the binding of IGF-1 to IGF-1R but also inhibit the signaling mediated by IGF-1R. Further work showed that B003-2A inhibited the proliferation of ovarian cancer cells in vivo and in vitro. In addition, the current study also indicates that B003-2A could enhance the sensitivity of cisplatin in cisplatin-resistant ovarian cancer cell lines. In summary, our research shows that B003-2A can be used to treat ovarian cancer. The current study also laid the foundation for the development of IGF-1R antagonist.

Long non-coding RNA DUXAP8 promotes tumorigenesis by regulating IGF1R via miR-9-3p in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide with a low 5-year survival rate. Long non-coding RNA (lncRNA) double homeobox A pseudogene 8 (DUXAP8) is an oncogene and a potential biomarker in various tumors, such as ovarian, colorectal and non-small-cell lung cancer. However, the function and molecular mechanism underlying DUXAP8 in HCC progression is not completely understood. The expression of DUXAP8, microRNA (miR)-9-3p and insulin-like growth factor 1 receptor (IGF1R) in HCC tissues and cells was detected via reverse transcription-quantitative PCR. The expression levels of IGF1R and epithelial-mesenchymal transition-associated proteins (Snail, Slug, E-cadherin, N-cadherin and vimentin) were assessed via western blotting. The effects of DUXAP8, miR-9-3p and IGF1R on proliferation, migration and invasion were examined by conducting Cell Counting Kit-8 and Transwell assays, respectively. The interaction between miR-9-3p and DUXAP8 or IGF1R was predicted using StarBase or TargetScan, and further assessed using dual luciferase reporter and RNA immunoprecipitation assays. DUXAP8 and IGF1R were upregulated and miR-9-3p was downregulated in HCC tissues and cells compared with adjacent healthy tissues and a normal liver cell line, respectively. miR-9-3p overexpression decreased the protein expression level of IGF1R, and miR-9-3p knockdown enhanced the protein expression level of IGF1R in HCC cells compared with the corresponding control groups. Moreover, compared with the corresponding control groups, DUXAP8 knockdown and miR-9-3p overexpression increased E-cadherin protein expression levels, and decreased Snail, Slug, N-cadherin and vimentin protein expression levels. However, miR-9-3p inhibitor and IGF1R overexpression reversed DUXAP8 knockdown- and miR-9-3p overexpression-induced effects, respectively. In addition, compared with the corresponding control groups, DUXAP8 knockdown and miR-9-3p overexpression suppressed proliferation, migration and invasion, which was reversed by miR-9-3p inhibitor and IGF1R overexpression, respectively. Moreover, miR-9-3p as the target of DUXAP8 and IGF1R as the target of miR-9-3p were verified in HCC cells. lncRNA DUXAP8 contributed to HCC tumorigenesis via the miR-9-3p/IGF1R axis, providing a novel therapeutic approach for HCC diagnosis and treatment.

NEAT1 Overexpression Indicates a Poor Prognosis and Induces Chemotherapy Resistance via the miR-491-5p/SOX3 Signaling Pathway in Ovarian Cancer

Background

Accumulated studies have reported that dysregulated long non-coding RNAs (lncRNAs) are crucial in ovarian cancer (OC) initiation and development. However, detailed biological functions of lncRNA NEAT1 during the progression of OC remains to be uncovered.

Purpose

Our aim was to identify the role of NEAT1 in cisplatin resistance of ovarian cancer and the underlying mechanisms.

Methods

The expression patterns of NEAT1 in OC cell lines and tissue samples were identified by qRT-PCR. The cisplatin (DDP) sensitivity of OC cells was detected by MTT and CCK8 assay, while OC cell apoptosis and cell cycle were detected using flow cytometer assays. In addition, effects of NEAT1 on tumor growth were determined by xenograft tumor model. Luciferase reporter assay was conducted to prove the regulatory relation of miR-491-5p, NEAT1, and SOX3. Importantly, the expression of NEAT1 in exosomes from cisplatin-resistant patients was also determined by using qRT-PCR.

Results

In this study, upregulated NEAT1 was detected in OC cell lines and tissues. Meanwhile, NEAT1 was also increased in cisplatin-resistant OC cell lines and tissues. Upregulation of NEAT1 inhibited cisplatin-induced OC cell apoptosis and promoted cell proliferation, while knockdown of NEAT1 played the opposite role. These effects were also observed in vivo. Furthermore, direct interaction was observed between NEAT1 and miR-491-5p. NEAT1 led to the upregulation of miR-491-5p-targeted SOX3 mRNA. Importantly, this study also showed upregulated NEAT1 expression in serum exosomes derived from cisplatin-resistant patients.

Conclusion

NEAT1 is vital in the chemoresistance of ovarian cancer through regulating miR-491-5p/SOX3 pathway, showing that NEAT1 might be a potential target for OC resistance treatment.

[MiR-300 inhibits invasion and metastasis of osteosarcoma cell MG63 by negatively regulating PTTG1]

OBJECTIVE

To investigate the effects of miR-300 and PTTG1 on osteosarcoma invasion and metastasis and explore the molecular mechanism of osteosarcoma invasion and metastasis.

OBJECTIVE

Western blot was used to detect the expression of PTTG1 in human osteoblasts hFOB1.19 and osteosarcoma cell MG63 and to detect the transfection efficiency of cells transfected with PTTG1-knockdown plasmid; Transwell invasion assay and CCK8 assay detected the effects of knockdown of PTTG1 and overexpression of miR-300 on the invasion and proliferation of osteosarcoma cell MG63. On-line prediction and screening of microRNAs (miRNAs) with complementary PTTG1 binding was conducted. qRT-PCR was performed to examine the expression of miR-300 in hFOB1.19 and MG63 cells, and Western blotting was used to detect the expression of PTTG1 in MG63 cells after transfection with a miR- 300 plasmid. Double luciferase assay was used to detect the targeted binding of miR-300 and PTTG, Transwell invasion assay and CCK8 assay were used to detect the effects of overexpression of miR-300 and overexpression of PTTG1 plasmid on invasion and proliferation of osteosarcoma cell line MG63.

OBJECTIVE

PTTG1 was highly expressed in MG63 cells (P=0.0002). PTTG1 knockdown significantly inhibited the invasion (P=0.0002) and proliferation (P=0.0039) of MG63 cells. Based on the results of online prediction of complementary miRNAs to PTTG1 and analysis of the data from NCBI database, miR-300 was determined as the target miRNA in this study. qRT-PCR results showed a significantly decreased expression of miR-300 in MG63 cells (P=0.0004). Overexpression of MiR-300 in MG63 cells significantly decreased the expression of PTTG1 (P=0.0007), and the expressions of miR-300 and PTTG1 were negatively correlated. Dual luciferase assay showed that miR-300 could specifically bind to PTTG1 (P=0.001). Overexpression of PTTG1 could significantly reverse the effect of miR-300 overexpression on invasion (P=0.0003) and proliferation (P=0.0077) of MG63 cells.

OBJECTIVE

Overexpression of miR-300 can inhibit the invasion and metastasis of osteosarcoma cell MG63 by targeting PTTG1.

MiRNA-mediated EMT and CSCs in cancer chemoresistance

Cancer stem cells (CSCs) are a small group of cancer cells, which contribute to tumorigenesis and cancer progression. Cancer cells undergoing epithelial-to-mesenchymal transition (EMT) acquire the chemoresistant ability, which is regarded as an important feature of CSCs. Thus, there emerges an opinion that the generation of CSCs is considered to be driven by EMT. In this complex process, microRNAs (miRNAs) are found to play a key role. In order to overcome the drug resistance, inhibiting EMT as well as CSCs phenotype seem feasible. Thereinto, regulating the EMT- or CSCs-associated miRNAs is a crucial approach. Herein, we conduct this review to elaborate on the complicated interplay between EMT and CSCs in cancer chemoresistance, which is modulated by miRNAs. In addition, we elucidate the therapeutic strategy to overcome drug resistance through targeting EMT and CSCs.

EMT-associated microRNAs and their roles in cancer stemness and drug resistance

Epithelial‐to‐mesenchymal transition (EMT) is implicated in a wide array of malignant behaviors of cancers, including proliferation, invasion, and metastasis. Most notably, previou studies have indicated that both cancer stem‐like properties and drug resistance were associated with EMT. Furthermore, microRNAs (miRNAs) play a pivotal role in the regulation of EMT phenotype, as a result, some miRNAs impact cancer stemness and drug resistance. Therefore, understanding the relationship between EMT‐associated miRNAs and cancer stemness/drug resistance is beneficial to both basic research and clinical treatment. In this review, we preliminarily looked into the various roles that the EMT‐associated miRNAs play in the stem‐like nature of malignant cells. Then, we reviewed the interaction between EMT‐associated miRNAs and the drug‐resistant complex signaling pathways of multiple cancers including lung cancer, gastric cancer, gynecologic cancer, breast cancer, liver cancer, colorectal cancer, pancreatic cancer, esophageal cancer, and nasopharyngeal cancer. We finally discussed the relationship between EMT, cancer stemness, and drug resistance, as well as looked forward to the potential applications of miRNA therapy for malignant tumors.

CircCAMSAP1 promotes hepatocellular carcinoma progression through miR-1294/GRAMD1A pathway

Hepatocellular carcinoma (HCC) is one of the most common cancers with high prevalence and mortality, and it has brought huge economic and health burden for the world. It is urgent to found novel targets for HCC diagnosis and clinical intervention. Circular RNA (circRNA) has been reported to participate in many cancer progressions including HCC, suggesting that circRNA might paly essential role in HCC initiation and progression. Our study aims to found that potential circRNA participates in HCC development and its underlying molecular mechanisms. We obtained three pairs of HCC tissues and its adjacent normal tissues data from GEO DataSets. MTT, cell colony, EdU, wound-healing, transwell invasion and mouse xenograft model assays were used to demonstrate the biological functions of circCAMSAP1 in HCC progression. Furthermore, we conducted bioinformatics analysis, AGO2-RIP, RNA pull-down and luciferase reporter assays to assess the association of circCAMSAP1-miR-1294-GRAMD1A axis in HCC cells. The expression of circCAMSAP1 was up-regulated in HCC tissues compared with its adjacent normal tissues. Up-regulation of circCAMSAP1 promoted HCC biological functions both in vitro and in vivo. The promotive effects of circCAMSAP1 on HCC progression function through miR-1294/GRAMD1A pathway. CircCAMSAP1 was up-regulated in HCC tissues, and circCAMSAP1 up-regulated GRAMD1A expression to promote HCC proliferation, migration and invasion through miR-1294. CircCAMSAP1 might be a potential prognosis and therapeutic target for HCC.

Arsenic trioxide-induced upregulation of miR-1294 suppresses tumor growth in hepatocellular carcinoma by targeting TEAD1 and PIM1

Recently, Arsenic trioxide (ATO) has been reported as an efficient drug for suppression of cancer cell growth. Existing studies revealed the extensive involvement of microRNAs (miRNAs) in initiation and development of hepatocellular carcinoma (HCC). However, the potential correlation between ATO and miRNAs in HCC progression remains to be explored. To conduct our research, we applied a qRT-PCR analysis to find miRNAs that were upregulated in HCC cells treated with ATO. In our present study, miR-1294 was found to be significantly upregulated in ATO-treated HCC cells. To confirm the function of ATO and miR-1294 in HCC progression, gain-of function assays were designed and conducted. As expected, proliferative ability of ATO-treated HCC cells was markedly weakened compared to DMSO-treated HCC cells. More importantly, proliferation was further suppressed in ATO-induced HCC cells after overexpression of miR-1294. Through bioinformatics analysis, some potential targets of miR-1294 were predicted. Further investigation revealed that Pim-1 proto-oncogene (PIM1) and TEA domain transcription factor 1 (TEAD1) were two downstream targets of miR-1294 and could be negatively regulated by ATO. Functionally, we determined that cell proliferation and apoptosis resistance suppressed by miR-1294 and ATO were recovered by introduction of TEAD1 and PIM1. Collectively, this study revealed that a novel ATO-miR-1294-TEAD1/PIM1 axis regulated HCC cell growth, offering a potential insight into the HCC therapy.

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.

Gynecologic cancers and non-coding RNAs: Epigenetic regulators with emerging roles

Gynecologic cancers involve the female genital organs, such as the vulva, vagina, cervix, endometrium, ovaries, and fallopian tubes. The occurrence and frequency of gynecologic cancer depends on personal lifestyle, history of exposure to viruses or carcinogens, genetics, body shape, and geographical habitat. For a long time, research into the molecular biology of cancer was broadly restricted to protein-coding genes. Recently it has been realized that non-coding RNAs (ncRNA), including long noncoding RNAs (LncRNAs), microRNAs, circular RNAs and piRNAs (PIWI-interacting RNAs), can all play a role in the regulation of cellular function within gynecological cancer. It is now known that ncRNAs are able to play dual roles, i.e. can exert both oncogenic or tumor suppressive functions in gynecological cancer. Moreover, several clinical trials are underway looking at the biomarker and therapeutic roles of ncRNAs. These efforts may provide a new horizon for the diagnosis and treatment of gynecological cancer. Herein, we summarize some of the ncRNAs that have been shown to be important in gynecological cancers.

Revisiting chemoresistance in ovarian cancer: Mechanism, biomarkers, and precision medicine

Among the gynecological cancers, ovarian cancer is the most lethal. Its therapeutic options include a combination of chemotherapy with platinum-based compounds and cytoreductive surgery. Most ovarian cancer patients exhibit an initial response to platinum-based therapy, however, platinum resistance has led to up to 80% of this responsive cohort becoming refractory. Ovarian cancer recurrence and drug resistance to current chemotherapeutic options is a global challenge. Chemo-resistance is a complex phenomenon that involves multiple genes and signal transduction pathways. Therefore, it is important to elucidate on the underlying molecular mechanisms involved in chemo-resistance. This inform decisions regarding therapeutic management and help in the identification of novel and effective drug targets. Studies have documented the individual biomarkers of platinum-resistance in ovarian cancer that are potential therapeutic targets. This review summarizes the molecular mechanisms of platinum resistance in ovarian cancer, novel drug targets, and clinical outcomes.

Identification of dysregulated miRNAs-genes network in ovarian cancer: An integrative approach to uncover the molecular interactions and oncomechanisms

Background

Ovarian (OV) cancer is considered as one of the most deadly malignancies in women, since it is unfortunately diagnosed in advanced stages. Nowadays, the importance of bioinformatics tools and their frequent usage in tracking dysregulated cancer‐related genes and pathways have been highlighted in researches.

Aim

The aim of this study is to investigate dysregulated miRNAs‐genes network and its function in OV tumors based on the integration of microarray data through a system biology approach.

Methods

Two microarray data (GSE119056 and GSE4122) were analyzed to explore the differentially expressed miRNAs (DEmiRs) and genes among OV tumors and normal tissues. Then, through the help of TargetScan, miRmap, and miRTarBase databases, the dysregulated miRNA‐gene network in OV tumors was constructed by Cytoscape. In the next step, co‐expression and protein‐protein interaction networks were made using GEPIA and STRING databases. Moreover, the functional analysis of the hub genes was done by DAVID, KEGG, and Enrichr databases. Eventually, the regulatory network of TF‐miRNA‐gene was constructed.

Results

The potential dysregulated miRNAs‐genes network in OV tumors has been constructed, including 109 differentially expressed genes (DEGs), 25 DEmiRs, and 213 interactions. Two down‐regulated microRNAs, miR‐660‐3p and hsa‐miR‐4510, have the most interactions with up‐expressed oncogenic DEGs. CDK1, PLK1, CCNB1, CCNA2, and EZH2 are involved in protein module, which show significant overexpression in OV tumors according to The Cancer Genome Atlas (TCGA) data. EZH2 shows amplification in OV tumors with remarkable percentage. The transcription factors TFAP2C and GATA4 have the pivotal regulatory functions in oncotranscriptomic profile of OV tumors.

Conclusion

In current study, we have collected and integrated different data to uncover the complex molecular interactions and oncomechanisms in OV tumors. The DEmiRs‐DEGs and TF‐miRNA‐gene networks reveal the potential interactions that could be a significant piece of the OV onco‐puzzle.

The circ-AMOTL1/ENO1 Axis Implicated in the Tumorigenesis of OLP-Associated Oral Squamous Cell Carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) may develop from a variety of oral potentially malignant disorders, but the mechanism of malignant transformation is still unknown. Among them, oral lichen planus (OLP) has a high prevalence. Previous studies have shown that α-enolase (ENO1) can promote cell proliferation and play an important role in tumorigenesis. In this study, we aim to explore the mechanism of ENO1 regulation in the process of OSCC tumorigenesis from OLP.

METHODS

ENO1 expression in tissues was determined by real-time quantitative PCR and immunohistochemistry. ENO1 was knocked down in cal-27 to observe the change in cell proliferation. Then, RNA-seq and bioinformatics analyses were conducted between OLP and OSCC samples. The expression of circ-AMOTL1, miRNA-22-3p, and miRNA-1294 was assessed using the real-time quantitative PCR. With knockdown and overexpression of circ-AMOTL1 in vitro, the change of ENO1 in the mRNA level was also assessed.

RESULTS

ENO1 was enhanced in the OSCC samples in comparison with OLP. Immunohistochemistry and real-time quantitative PCR results showed that ENO1 was significantly higher in OSCC tissue than in the OLP group, with a statistically significant difference (p<0.05). When ENO1 was knocked down in cal-27, cell proliferation was inhibited (p<0.05). The expression of miR-22-3p and miR-1294 was decreased in OSCC tissues, whereas ENO1 and circ-AMOTL1 increased. In an in vitro study, knockdown of circ-AMOTL1 resulted in a decrease of ENO1, while overexpression of circ-AMOTL1 led to an increase of ENO1 in the mRNA level.

CONCLUSION

We confirmed that ENO1 expression was elevated in OSCC and increased cell proliferation. In an in vitro study, ENO1 expression was promoted by circ-AMOTL1. ENO1 may play a role as a tumor-promoting gene in OSCC through the circ-AMOTL1/miR-22-3p/miR-1294 network. These novel findings may shed further light on the pathogenesis from OLP to OSCC and the potential precursor markers.

Identification of key genes for guiding chemotherapeutic management in ovarian cancer using translational bioinformatics

The emergence of resistance to chemotherapy drugs in patients with ovarian cancer is still the main cause of low survival rates. The present study aimed to identify key genes that may provide treatment guidance to reduce the incidence of drug resistance in patients with ovarian cancer. Original data of chemotherapy sensitivity and chemoresistance of ovarian cancer were obtained from the Gene Expression Omnibus dataset GSE73935. Differentially expressed genes (DEGs) between sensitive and resistant ovarian cancer cell lines were screened by Empirical Bayes methods. Overlapping DEGs between four chemoresistant groups were identified by Venn map analysis. Protein-protein interaction networks were also constructed, and hub genes were identified. The hub genes were verified by in vitro experiments as well as The Cancer Genome Atlas data. Results from the present study identified eight important genes that may guide treatment decisions regarding chemotherapy regimens for ovarian cancer, including epidermal growth factor-like repeats and discoidin I-like domains 3, NRAS proto-oncogene, hyaluronan and proteoglycan link protein 1, activated protein C receptor, CD53, cyclin-dependent kinase inhibitor 2A, insulin-like growth factor 1 receptor and roundabout guidance receptor 2 genes. Their expressions were found to have an impact on the prognosis of different treatment groups (cisplatin, paclitaxel, cisplatin + paclitaxel, cisplatin + doxorubicin and cisplatin + topotecan). The results indicated that these genes may minimise the occurrence of ovarian cancer drug resistance and may provide effective treatment options for patients with ovarian cancer.

Roles of microRNAs in Ovarian Cancer Tumorigenesis: Two Decades Later, What Have We Learned?

Ovarian cancer is one of the top gynecological malignancies that cause deaths among females in the United States. At the molecular level, significant progress has been made in our understanding of ovarian cancer development and progression. MicroRNAs (miRNAs) are short, single-stranded, highly conserved non-coding RNA molecules (19–25 nucleotides) that negatively regulate target genes post-transcriptionally. Over the last two decades, mounting evidence has demonstrated the aberrant expression of miRNAs in different human malignancies, including ovarian carcinomas. Deregulated miRNAs can have profound impacts on various cancer hallmarks by repressing tumor suppressor genes. This review will discuss up-to-date knowledge of how the aberrant expression of miRNAs and their targeted genes drives ovarian cancer initiation, proliferation, survival, and resistance to chemotherapies. Understanding the mechanisms by which these miRNAs affect these hallmarks should allow the development of novel therapeutic strategies to treat these lethal malignancies.

MicroRNA-654-3p enhances cisplatin sensitivity by targeting QPRT and inhibiting the PI3K/AKT signaling pathway in ovarian cancer cells

Dysregulation of microRNAs serves a crucial role in the chemosensitivity to cisplatin (DDP) in ovarian cancer (OVC). The abnormal expression of microRNA (miR)-654-3p has been reported in several types of human cancer. However, the association between miR-654-3p and cisplatin resistance in human OVC remains unclear. The present study aimed to investigate the role and mechanism of miR-654-3p in DDP resistance in OVC. The results demonstrated that miR-654-3p was significantly downregulated in ovarian cancer tissues and cells, as well as DDP-resistant IGROV-1/DDP cells, compared with adjacent non-tumoral tissue and IOSE386 cells. Overexpression of miR-654-3p significantly suppressed the proliferation and migration of ovarian cancer cells and increased the sensitivity of IGROV-1/DDP cells to DDP. Luciferase reporter assay demonstrated that quinolinate phosphoribosyl transferase (QPRT) was a target of miR-654-3p; overexpression of miR-654-3p inhibited QPRT expression by binding to the 3'-untranslated region of QPRT. In addition, inhibition of miR-654-3p reversed the suppressive effects of QPRT-targeting short interfering RNA on the proliferation and chemoresistance of ovarian cancer cells. Therefore, the results of the present study revealed a previously unrecognized regulatory mechanism that miR-654-3p enhances DDP sensitivity of OVC cells by downregulating QPRT expression; in addition, the present study highlighted the therapeutic implications of miR-654-3p upregulation in OVC.

Antitumor Effect of miR-1294/Pyruvate Kinase M2 Signaling Cascade in Osteosarcoma Cells

Background

MicroRNAs (miRNAs) can act as negative regulators of gene expression, and play a crucial role in cancer progression. The aim of this study was to investigate the role of miR-1294/pyruvate kinase M2 (PKM2) axis in osteosarcoma cells in vitro and in vivo.

Methods

The function of miR-1294 and its association with PKM2 in osteosarcoma cells were studied by real-time PCR, CCK-8, Western blot, scratch test, transwell assay, flow cytometry, and dual-luciferase reporter assays. The effect of miR-1294 on tumor growth in vivo was evaluated in a subcutaneous xenograft model of osteosarcoma.

Results

miR-1294 was downregulated in osteosarcoma cells. Forced overexpression of miR-1294 inhibited cell proliferation, migration, and invasion, and induced G0/G1 arrest and apoptosis. Consistently, protein expression levels of proliferating cell nuclear antigen, c-Myc, cyclin D1, active matrix metalloproteinase 2, and active matrix metalloproteinase 9 were decreased, and cleaved caspase 3 and cleaved PARP were increased following miR-1294 overexpression. Moreover, we demonstrated that PKM2 was a target of miR-1294 in osteosarcoma cells, and the effects caused by miR-1294 mimic were reversed by the overexpression of PKM2. Furthermore, we found that upregulation of miR-1294 inhibited tumorigenesis of osteosarcoma cells in vivo, which was accompanied by downregulation of PKM2.

Conclusion

Our results revealed that miR-1294/PKM2 signaling cascade exerts important roles in the regulation of tumor progression, implying that this pathway may serve as a potential therapeutic target in osteosarcoma.

miR-1294 alleviates epithelial-mesenchymal transition by repressing FOXK1 in gastric cancer

BACKGROUND

MicroRNAs (miRNAs) have been reported play critical roles in regulating tumor development and progression.

OBJECTIVE

This study aimed to investigate the potential effect of miR-1294 in gastric cancer (GC).

METHODS

Reverse transcription quantitative polymerase chain reaction (RT-PCR) were performed to verify the expression level of miR-1294 and Forkhead box protein K1 (FOXK1). Overall survival data of miR-1294 for GC was analysed by log-rank test. Targetscan was used to screen potential target gene of miR-1294. Dual luciferase assay was assessed to investigate the relationship between miR-1294 and FOXK1. The miR-1294 overexpression and knockdown were designed to study the biological function of miR-1294. The migration and invasion of GC cell lines were investigated by wound healing and transwell assays. Western blotting were performed to verify the expression level of epithelial marker, mesenchymal markers and FOXK1. Overexpression of FOXK1 was designed to study the rescue effects of FOXK1 in SGC7901 cell.

RESULTS

miR-1294 was found downregulated in GC patients and cell lines. A higher miR-1294 expression showed a significant longer overall survival than those with a lower miR-1294 expression. miR-1294 directly targets FOXK1 and regulates the expression of FOXK1. In addition, miR-1294 regulates epithelial-mesenchymal transition (EMT) by inhibiting FOXK1 in GC cells and it can be rescued by overexpression of FOXK1.

CONCLUSION

miR-1294 alleviates EMT process in GC by targeting FOXK1.

Endosomal TLR-8 Senses microRNA-1294 Resulting in the Production of NFḱB Dependent Cytokines

The primary function of toll-like receptor 8 (TLR-8) is the detection of viruses and other microbial pathogens. Recent evidence suggests that TLR-8 also senses host microRNAs (miRNAs) and implicate TLR-8 in autoimmune disorders. This study examined the interaction between miR-1294 and TLR-8. We first performed a BLAST search to identify miRNAs with the same sequences as two core motifs of miR-1294. Next, we examined NFḱB activation induced by the binding of miR-1294 mimic to endosomal TLR-8. HEK-Blue™ hTLR-8 cells (Invivogen), a HEK293 cell line co-transfected with human TLR-8 gene, were incubated with miR-1294 mimic. A TLR-8 agonist ssRNA40, was used as a positive control. Using the same experimental set up, we also examined the effects of miR-1294 and its two core motifs (Integrated DNA Technologies) on IL-8, IL-1β, and TNFα. Data were analyzed using t-test or one-way ANOVA and Dunnets post-hoc test. Using miRCarta we identified 29 other mature human miRNAs or their precursors which contain the same core motifs as miR-1294. Our data show that miR-1294 activates NFḱB in cells expressing TLR-8 (p < 0.05). miR-1294, and its core motifs induce expression of IL-8, IL-1β, and TNFα via TLR8 activation (p < 0.05). This constitutes a novel mechanism by which endosomal TLR-8 senses host miRNAs resulting in the release of pro-inflammatory cytokines and thus potentially contributing to autoimmune disorders.

Downregulation of lncRNA SNHG12 reversed IGF1R-induced osteosarcoma metastasis and proliferation by targeting miR-195-5p

Long non-coding RNA SNHG12 (lncSNHG12) plays important roles in the onset and progression of various cancers. However, the role of lncSNHG12 in osteosarcoma (OS) remains unclear. Therefore, the aim of the present study was to determine the function of lncSNHG12 in OS. A bioinformatics website was used to predict the downstream targets of lncSNHG12. In addition, qRT-PCR was employed to assess lncSNHG12 expression in OS cells. Cell migration and proliferation in vitro were verified using the transwell migration, clone formation, and CCK8 assays. Tumor metastasis and xenograft formation were monitored in nude mice with or without downregulation of lncSNHG12. The results show that lncSNHG12 was upregulated in OS cell lines. Downregulation lncSNHG12 suppressed the metastasis and proliferation both in vitro and in vivo. Also, lncSNHG12 downregulation suppressed the expression of insulin growth factor 1 receptor (IGF1R) expression through sponging miR-195-5p, which was verified with the luciferase reporter assay and rescue experiments. These findings suggest that downregulation of lncSNHG12 may suppress aggressive OS phenotypes. Moreover, lncSNHG12 silencing inhibited OS metastasis and growth by targeting the miR-195-5p/IGF1R axis, which represents a candidate marker and target for OS treatment and management.

Cisplatin decreases cyclin D2 expression via upregulating miR‑93 to inhibit lung adenocarcinoma cell growth

MicroRNAs (miRNAs/miRs) serve important roles in the chemotherapeutic effect of anticancer drugs. To investigate the roles of miRNAs in cisplatin‑induced suppression of lung adenocarcinoma cell proliferation, A549 cells were treated with different concentrations of cisplatin. An MTT assay demonstrated that cisplatin inhibited A549 cell proliferation in a dose‑dependent manner. Cisplatin induced cell apoptosis and inhibited cell migration by increasing the levels of miR‑93, miR‑26a and miR‑26b. Furthermore, as an upstream factor, miR‑93 was proposed to regulate cyclin D2 expression in miR‑93‑transfected A549 cells. Cisplatin also induced Bcl‑2‑associated X protein expression, and decreased that of Bcl‑2 and c‑Myc in lung adenocarcinoma cells. In vivo analysis further supported that cisplatin inhibited lung adenocarcinoma cell growth by regulating cyclin D2 and miR‑93 expression. In conclusion, our findings demonstrated that cisplatin could effectively inhibit lung adenocarcinoma cell proliferation by decreasing cyclin D2 expression via miR‑93.

The Role of Epithelial-to-Mesenchymal Plasticity in Ovarian Cancer Progression and Therapy Resistance

Ovarian cancer is the most lethal of all gynecologic malignancies and the eighth leading cause of cancer-related deaths among women worldwide. The main reasons for this poor prognosis are late diagnosis; when the disease is already in an advanced stage, and the frequent development of resistance to current chemotherapeutic regimens. Growing evidence demonstrates that apart from its role in ovarian cancer progression, epithelial-to-mesenchymal transition (EMT) can promote chemotherapy resistance. In this review, we will highlight the contribution of EMT to the distinct steps of ovarian cancer progression. In addition, we will review the different types of ovarian cancer resistance to therapy with particular attention to EMT-mediated mechanisms such as cell fate transitions, enhancement of cancer cell survival, and upregulation of genes related to drug resistance. Preclinical studies of anti-EMT therapies have yielded promising results. However, before anti-EMT therapies can be effectively implemented in clinical trials, more research is needed to elucidate the mechanisms leading to EMT-induced therapy resistance.