Strategies to overcome chemoresistance in epithelial ovarian cancer: Navigating beyond challenges

Epithelial ovarian cancer (EOC) is the most fetal gynecological malignancy. The main causes of treatment failure are primary and acquired chemoresistance that remains a major therapeutic challenge. The mechanisms underlying chemoresistance in EOC are complex and not fully understood. This review explores novel therapeutic strategies targeting chemoresistant EOC, including advanced drug delivery systems, targeting non-coding RNAs, peptide-based therapies, immunotherapy, and the use of poly-ADP ribose polymerase inhibitors. By summarizing the latest research and potential treatments, this review aims to contribute to the development of more effective therapies for patients with chemoresistant EOC.

Survival and biomarker analysis for cancer‑associated thromboembolism in ovarian clear cell carcinoma

The present study aimed to investigate the impact of cancer-associated thromboembolism (CAT) on the survival and biomarkers of ovarian clear cell carcinoma (OCCC). Patients with OCCC who underwent surgery at the National Defense Medical College Hospital (Tokorozawa, Japan) between January 2000 and December 2019 were included in the current study. Associations among CAT, clinicopathological features and prognosis were retrospectively compared. Furthermore, immunohistochemical staining was conducted in all patients to compare differences between patients with and without CAT. Among 111 patients with OCCC, 20 patients (18.0%) had CAT complications. CAT was detected in 12 patients (10.8%) before primary treatment and in 8 patients (7.2%) after primary surgery. Patients with CAT experienced more tumor recurrence (P=0.048) and platinum resistance (P=0.025), had worse progression-free survival (PFS; P<0.01) and overall survival (OS; P<0.01), and multivariate analysis showed that CAT was a prognostic factor for worse PFS [hazard ratio (HR)=2.10, P=0.039] and OS (HR=4.26, P<0.01). Moreover, immunohistochemical analysis revealed that more OCCC cases with CAT were positive for tissue factor (TF; P=0.030) and phosphorylated-Janus kinase 2 (JAK2; P=0.034) expression than those without CAT. In conclusion, CAT may be associated with platinum resistance and poor prognosis in patients with OCCC. Furthermore, TF and JAK2 could be considered potential novel therapeutic targets for OCCC complicated by CAT.

Interleukin-6 Modulation in Ovarian Cancer Necessitates a Targeted Strategy: From the Approved to Emerging Therapies

Despite significant advances in treatments, ovarian cancer (OC) remains one of the most prevalent and lethal gynecological cancers in women. The frequent detection at the advanced stages has contributed to low survival rates, resistance to various treatments, and disease recurrence. Thus, a more effective approach is warranted to combat OC. The cytokine Interleukin-6 (IL6) has been implicated in various stages of OC development. High IL6 levels are also correlated with a lower survival rate in OC patients. In this current review, we summarized the pivotal roles of IL6 in OC, including the initiation, development, invasion, metastasis, and drug resistance mechanisms. This article systematically highlights how targeting IL6 improves OC outcomes by altering various cancer processes and reports the ongoing clinical trials that would further shape the IL6-based targeted therapies. This review also suggests how combining IL6-targeted therapies with other therapeutic strategies could further enhance their efficacy to combat OC.

Screening and identification of key biomarkers associated with endometriosis using bioinformatics and next-generation sequencing data analysis

Background

Endometriosis is a common cause of endometrial-type mucosa outside the uterine cavity with symptoms such as painful periods, chronic pelvic pain, pain with intercourse and infertility. However, the early diagnosis of endometriosis is still restricted. The purpose of this investigation is to identify and validate the key biomarkers of endometriosis.

Methods

Next-generation sequencing dataset GSE243039 was obtained from the Gene Expression Omnibus database, and differentially expressed genes (DEGs) between endometriosis and normal control samples were identified. After screening of DEGs, gene ontology (GO) and REACTOME pathway enrichment analyses were performed. Furthermore, a protein–protein interaction (PPI) network was constructed and modules were analyzed using the Human Integrated Protein–Protein Interaction rEference database and Cytoscape software, and hub genes were identified. Subsequently, a network between miRNAs and hub genes, and network between TFs and hub genes were constructed using the miRNet and NetworkAnalyst tool, and possible key miRNAs and TFs were predicted. Finally, receiver operating characteristic curve analysis was used to validate the hub genes.

Results

A total of 958 DEGs, including 479 upregulated genes and 479 downregulated genes, were screened between endometriosis and normal control samples. GO and REACTOME pathway enrichment analyses of the 958 DEGs showed that they were mainly involved in multicellular organismal process, developmental process, signaling by GPCR and muscle contraction. Further analysis of the PPI network and modules identified 10 hub genes, including vcam1, snca, prkcb, adrb2, foxq1, mdfi, actbl2, prkd1, dapk1 and actc1. Possible target miRNAs, including hsa-mir-3143 and hsa-mir-2110, and target TFs, including tcf3 (transcription factor 3) and clock (clock circadian regulator), were predicted by constructing a miRNA-hub gene regulatory network and TF-hub gene regulatory network.

Conclusions

This investigation used bioinformatics techniques to explore the potential and novel biomarkers. These biomarkers might provide new ideas and methods for the early diagnosis, treatment and monitoring of endometriosis.

Interleukin-6 serves as a critical factor in various cancer progression and therapy

Interleukin-6 (IL-6), a pro-inflammatory cytokine, plays a crucial role in host immune defense and acute stress responses. Moreover, it modulates various cellular processes, including proliferation, apoptosis, angiogenesis, and differentiation. These effects are facilitated by various signaling pathways, particularly the signal transducer and activator of transcription 3 (STAT3) and Janus kinase 2 (JAK2). However, excessive IL-6 production and dysregulated signaling are associated with various cancers, promoting tumorigenesis by influencing all cancer hallmarks, such as apoptosis, survival, proliferation, angiogenesis, invasiveness, metastasis, and notably, metabolism. Emerging evidence indicates that selective inhibition of the IL-6 signaling pathway yields therapeutic benefits across diverse malignancies, such as multiple myeloma, prostate, colorectal, renal, ovarian, and lung cancers. Targeting key components of IL-6 signaling, such as IL-6Rs, gp130, STAT3, and JAK via monoclonal antibodies (mAbs) or small molecules, is a heavily researched approach in preclinical cancer studies. The purpose of this study is to offer an overview of the role of IL-6 and its signaling pathway in various cancer types. Furthermore, we discussed current preclinical and clinical studies focusing on targeting IL-6 signaling as a therapeutic strategy for various types of cancer.

Targeting interleukin-6 as a treatment approach for peritoneal carcinomatosis

Peritoneal carcinomatosis (PC) is a complex manifestation of abdominal cancers, with a poor prognosis and limited treatment options. Recent work identifying high concentrations of the cytokine interleukin-6 (IL-6) and its soluble receptor (sIL-6-Rα) in the peritoneal cavity of patients with PC has highlighted this pathway as an emerging potential therapeutic target. This review article provides a comprehensive overview of the current understanding of the potential role of IL-6 in the development and progression of PC. We discuss mechansims by which the IL-6 pathway may contribute to peritoneal tumor dissemination, mesothelial adhesion and invasion, stromal invasion and proliferation, and immune response modulation. Finally, we review the prospects for targeting the IL-6 pathway in the treatment of PC, focusing on common sites of origin, including ovarian, gastric, pancreatic, colorectal and appendiceal cancer, and mesothelioma.

Immunotherapy for Ovarian Cancer: Disappointing or Promising?

Ovarian cancer, one of the deadliest malignancies, lacks effective treatment, despite advancements in surgical techniques and chemotherapy. Thus, new therapeutic approaches are imperative to improving treatment outcomes. Immunotherapy, which has demonstrated considerable success in managing various cancers, has already found its place in clinical practice. This review aims to provide an overview of ovarian tumor immunotherapy, including its basics, key strategies, and clinical research data supporting its potential. In particular, this discussion highlights promising strategies such as checkpoint inhibitors, vaccines, and pericyte transfer, both individually and in combination. However, the advancement of new immunotherapies necessitates large controlled randomized trials, which will undoubtedly shape the future of ovarian cancer treatment.

The Role of Cytokines in Activation of Tumour-promoting Pathways and Emergence of Cancer Drug Resistance

Scientists are constantly researching and launching potential chemotherapeutic agents as an irreplaceable weapon to fight the battle against cancer. Despite remarkable advancement over the past several decades to wipe out cancer through early diagnosis, proper prevention, and timely treatment, cancer is not ready to give up and leave the battleground. It continuously tries to find some other way to give a tough fight for its survival, either by escaping from the effect of chemotherapeutic drugs or utilising its own chemical messengers like cytokines to ensure resistance. Cytokines play a significant role in cancer cell growth and progression, and the present article highlights their substantial contribution to mechanisms of resistance toward therapeutic drugs. Multiple clinical studies have even described the importance of specific cytokines released from cancer cells as well as stromal cells in conferring resistance. Herein, we discuss the different mechanism behind drug resistance and the crosstalk between tumor development and cytokines release and their contribution to showing resistance towards chemotherapeutics. As a part of this review, different approaches to cytokines profile have been identified and employed to successfully target new evolving mechanisms of resistance and their possible treatment options.

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.

Curcumin: a natural organic component that plays a multi-faceted role in ovarian cancer

Curcumin, a natural organic component obtained from Curcuma longa's rhizomes, shows abundant anti-tumor, antioxidant and anti-inflammatory pharmacological activities, among others. Notably the anti-tumor activity has aroused widespread attention from scholars worldwide. Numerous studies have reported that curcumin can delay ovarian cancer (OC), increase its sensitivity to chemotherapy, and reduce chemotherapy drugs' side effects. It has been shown considerable anticancer potential by promoting cell apoptosis, suppressing cell cycle progression, inducing autophagy, inhibiting tumor metastasis, and regulating enzyme activity. With an in-depth study of curcumin's anti-OC mechanism, its clinical application will have broader prospects. This review summarizes the latest studies on curcumin's anti-OC activities, and discusses the specific mechanism, hoping to provide references for further research and applications.

Evaluation of the Tocilizumab therapy in human cancers: Latest evidence and clinical potential

Tocilizumab (Actemra®), as the first human interleukin-6 receptor (IL-6R) antagonist, has been used in treating moderate to severe active rheumatoid arthritis (RA) patients who were undertreatment with one or more disease-modifying anti-rheumatic drugs (DMARDs) and did not improve significantly. Tocilizumab also has been administrated and confirmed in several inflammatory-based diseases. Recently, tocilizumab has been prescribed to treat patients with advanced coronavirus disease (COVID-19) and is used as one of the effective drugs in reducing the increased inflammation in these patients. On the other hand, cancer treatment has been considered by researchers one of the most important challenges to human health. Regarding inflammatory-associated malignancies, it has been shown that inflammatory mediators such as interleukin-1 beta (IL-1β), IL-6, and tumour necrosis factor-alpha (TNF-α) may play a role in tumorigenesis, thus targeting these cytokines as evidence suggested can be useful in the treatment of these types of cancers. This review summarized the role of the IL-6/IL-6R axis in inflammation-based cancers and discussed the effectiveness and challenges of treating cancer with tocilizumab.

Drug Resistance in Cancers: A Free Pass for Bullying

The cancer burden continues to grow globally, and drug resistance remains a substantial challenge in cancer therapy. It is well established that cancerous cells with clonal dysplasia generate the same carcinogenic lesions. Tumor cells pass on genetic templates to subsequent generations in evolutionary terms and exhibit drug resistance simply by accumulating genetic alterations. However, recent evidence has implied that tumor cells accumulate genetic alterations by progressively adapting. As a result, intratumor heterogeneity (ITH) is generated due to genetically distinct subclonal populations of cells coexisting. The genetic adaptive mechanisms of action of ITH include activating "cellular plasticity", through which tumor cells create a tumor-supportive microenvironment in which they can proliferate and cause increased damage. These highly plastic cells are located in the tumor microenvironment (TME) and undergo extreme changes to resist therapeutic drugs. Accordingly, the underlying mechanisms involved in drug resistance have been re-evaluated. Herein, we will reveal new themes emerging from initial studies of drug resistance and outline the findings regarding drug resistance from the perspective of the TME; the themes include exosomes, metabolic reprogramming, protein glycosylation and autophagy, and the relates studies aim to provide new targets and strategies for reversing drug resistance in cancers.

Interleukin-6-derived cancer-associated fibroblasts activate STAT3 pathway contributing to gemcitabine resistance in cholangiocarcinoma

Cancer-associated fibroblasts (CAFs) are the dominant component of the tumor microenvironment (TME) that can be beneficial to the generation and progression of cancer cells leading to chemotherapeutic failure via several mechanisms. Nevertheless, the roles of CAFs on anti-cancer drug response need more empirical evidence in cholangiocarcinoma (CCA). Herein, we examined the oncogenic roles of CAFs on gemcitabine resistance in CCA cells mediated via IL-6/STAT3 activation. Our findings showed that CCA-derived CAFs promote cell viability and enhance gemcitabine resistance in CCA cells through the activation of IL-6/STAT3 signaling. High expression of IL-6R was correlated with a poor overall survival rate and gemcitabine resistance in CCA, indicating that IL-6R can be a prognostic or predictive biomarker for the chemotherapeutic response of CCA patients. Blockade of IL-6R on CCA cells by tocilizumab, an IL-6R humanized antihuman monoclonal antibody, contributed to inhibition of the CAF-CCA interaction leading to enhancement of gemcitabine sensitivity in CCA cells. The results of this study should be helpful for modifying therapeutic regimens aimed at targeting CAF interacting with cancer cells resulting in the suppression of the tumor progression but enhancement of drug sensitivity.

The Role of Cancer-Associated Fibroblasts in Ovarian Cancer

Ovarian cancer is a lethal gynecologic tumor and is generally resistant to conventional treatments. Stable cancer-associated fibroblasts (CAFs) are important cellular components in the ovarian cancer tumor microenvironment and may provide novel resources for future treatment strategies. Different subtypes of CAFs display specific functions in tumor pathogenesis and various CAF markers suggest potential treatment targets, such as FAP and GPR77. Both autocrine and paracrine cytokines play important roles in the CAF activation process and regulate tumor progression. Downstream mediators and pathways, including IL-6, TGF-β, NF-κB, mitogen-activated protein kinase (MAPK), and AKT/mTOR/(p70S6K), play important roles in the initiation, proliferation, invasiveness, and metastasis of ovarian cancer cells and also participate in angiogenesis, therapeutic resistance, and other biological processes. Several clinical or preclinical trials have targeted stromal fibroblasts and focused on the properties of CAFs to enhance ovarian cancer treatment outcomes. This review concentrates on the origins, subtypes, and activation of CAFs, as well as specific roles of CAFs in regulating tumor development and drug resistance, and aims to provide potential and prospective targets for improving the therapeutic efficacy of ovarian cancer treatment.

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.

Long non-coding RNA AC087388.1 as a novel biomarker in colorectal cancer

Background

Several investigations have reported diverse roles of long non-coding RNA (lncRNA) in biological processes, tumor development, and progression of colorectal cancer (CRC). In this study, we investigated the lncRNA AC087388.1 tumorigenic role in CRC cells.

Methods

The CRC tissues were collected at the Reza Radiotherapy and Oncology Center, Mashhad, Iran. The human SW-48 and HT-29 CRC cell lines were obtained from the national cell bank of Iran. The cells were cultured according to ATCC (the American Type Culture Collection) recommendations. Quantitative real-time PCR was applied to assess the RNA expression. ShRNA transfection was done to downregulate the target gene. MTT and apoptosis assays were conducted to evaluate cell proliferation and viability, respectively. Colony formation assay, wound healing assay, and invasion assay were applied to determine growth, motility, and invasion of the cells, respectively. ENCORI online tool was used as downstream enrichment analysis.

Results

Forty CRC patients were encompassed in this study. The results demonstrated that the lncRNA SLC16A1-AS1, AC087388.1, and ELFN1-AS1 were significantly overexpressed in the CRC tissues in comparison to their normal counterpart margins. All the lncRNAs have shown significant Area Under Curve (AUC) values in the patients. Downregulation of lncRNA AC087388.1 remarkably decreased the cell proliferation and viability of the CRC cells. In addition, the data demonstrated that the downregulation of lncRNA AC087388.1 significantly suppressed cell growth and colony formation capability in the cells. Also, downregulation of lncRNA AC087388.1 attenuated motility and invasion of CRC cells, and significantly decreased the expression of invasion genes. In-silico functional enrichment analysis indicated that the lncRNA AC087388.1 has contributed to crucial signaling pathways in tumorigenesis such as the p53 and Wnt signaling pathways, apoptosis, and cell cycle.

Conclusions

Altogether, we showed that lncRNA AC087388.1 has an oncogenic role in tumorigenesis of CRC, and it can be considered as a novel diagnostic and prognostic biomarker in CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09282-0.

The implication of IL-6 in the invasiveness and chemoresistance of ovarian cancer cells. Systematic review of its potential role as a biomarker in ovarian cancer patients

Interleukin 6 (IL-6) is a pleiotropic cytokine that is strongly implicated in the development and progression of ovarian cancer. The most recognized actions of IL-6 in ovarian cancer (OC) cells are the induction of cell proliferation and inhibition of cell apoptosis. Equally important is its ability to enhance the migratory and invasive potential of OC cells. Moreover, the increased expression and secretion of this cytokine positively correlates with OC cell chemoresistance. Elevated concentrations of IL-6 are observed in the serum and ascites of ovarian cancer patients. Thus, its level is discussed in the literature as a potential biomarker that can help to discriminate malignant and nonmalignant ovarian tumors and allow for the prediction of the chemotherapy response. The importance of IL-6 in ovarian cancer is proved by the fact that this cytokine is a potential target to anti-cancer therapy. This review is divided into two parts. The first summarizes the general biological activity of IL-6, and overviews its impact on OC cells, as well as discusses the current proposition of IL-6 inclusion in combination of anti-OC therapy. The second part is a systematic review of IL-6 as a possible biomarker in ovarian cancer patients.

ITIH4 is a novel serum biomarker for early gastric cancer diagnosis

BACKGROUND

Gastric cancer (GC) is one of the most lethal forms of cancer due to the absence of tools for its early detection. Here, we explored critical biomarkers for early diagnosis.

MATERIALS AND METHODS

Key biomarkers in serum from patients with early gastric cancer (EGC) and healthy controls (HCs) were identified via mass spectrometry and the expression of inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) was evaluated using several methods. Furthermore, ITIH4 expression in sera and exosomes from patients with EGC, advanced GC (AGC), low grade intraepithelial neoplasia (LGN), chronic superficial gastritis with Helicobacter pylori infection (Hpi), other systemic malignant tumors (OSTs), and healthy controls was also evaluated.

RESULTS

ITIH4 was identified as a key biomarker in patients with EGC. Its expression level in serum from the EGC group, which showed the highest specificity (94.44%), was significantly higher than those in sera from other GC groups as well as the control. Western blot analysis, immunohistochemical staining, and exosome analysis also confirmed ITIH4 expression in sera from patients with GC, but not in those from healthy individual.

CONCLUSION

ITIH4 is a key biomarker in serum from patients with EGC and has potential as a high value diagnostic marker for EGC.

Inexpensive Systemic Inflammatory Biomarkers in Ovarian Cancer: An Umbrella Systematic Review of 17 Prognostic Meta-Analyses

The association of several inflammation-based biomarkers [lymphocyte-to-monocyte, neutrophil-to-lymphocyte, and platelet-to-lymphocyte ratios (LMR, NLR, and PLR, respectively)] with the survival of epithelial ovarian cancer (EOC) patients has been extensively investigated in several systematic reviews and meta-analyses (MAs) of observational studies. The aim of this umbrella systematic review is to appraise all available results in published MAs that explored the association between these biomarkers and EOC outcomes. An umbrella systematic review of the current evidence for systemic inflammatory biomarkers in the peripheral blood of EOC patients was performed by searching several databases including PubMed/Medline and Web of Science. The quality of the MAs was appraised using the AMSTAR-2 tool as well as other qualitative criteria. The evidence was graded from convincing (Class I) to weak (Class IV). Our umbrella review appraised 17 MAs of retrospective studies (range: 7-16) with a number of enrolled patients ranging from 1,636 to 4,910 patients in each MA. All these MAs demonstrated that pretreatment high NLR and PLR, as well as low LMR, were independent predictors of poor overall survival and progression-free survival in EOC. Nearly all published MAs were conducted by Chinese researchers (16/17) and were redundant in their character. Another issue in these MAs is the absence of prior PROSPERO database registration as well as the earlier exclusion of the gray literature. On the other hand, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analyses Of Observational Studies in Epidemiology (MOOSE)-based reporting guidelines were used in nine out of the 17 MAs. A good number of MAs have transparently provided funding acknowledgment. The AMSTAR-2-based assessment showed low quality in 11 out of the 17 reviewed MAs. This negative rating was largely due to the absence of critical domains. Finally, all evaluated MAs were rated as Class III or IV (suggestive and weak, respectively). Despite the power of MAs in increasing sampling and precision, the quality of the current non-randomized evidence on this topic is still weak.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42020201493.

Interleukin-6 reverses Adriamycin resistance in nasal NK/T-cell lymphoma via downregulation of ABCC4 and inactivation of the JAK2/STAT3/NF-κB/P65 pathway

Chemotherapy is generally effective for extranodal natural killer (NK)/T-cell lymphoma (ENKTCL), nasal type. Nevertheless, multidrug resistance (MDR) remains a key challenge in treating nasal NK/T-cell lymphoma. Interleukin-6 (IL-6) is reportedly an important regulator of MDR in many cancers, implicating a role of IL-6 in the chemotherapy response. However, the effects and mechanism of IL-6 in nasal NK/T-cell lymphoma remain unclear. Herein, we demonstrated that the IL-6 serum level was decreased in nasal NK/T-cell lymphoma patients compared to chronic rhinitis patients. Lower serum levels of IL-6 were closely correlated with Ki67 expression and patient survival. ATP-binding cassette (ABC) drug transporter ABCC4 in patients was abnormally upregulated. IL-6 significantly inhibited resistance to Adriamycin (ADM) in ADM-resistant SNK-6 cells (SNK-6/ADM). Moreover, IL-6 resulted in cell cycle arrest and led to apoptosis in SNK-6/ADM cells. Furthermore, IL-6 decreased ABCC4, p-JAK2, p-STAT3, and phospho-NF-κB p65 expression in SNK-6/ADM cells. IL-6 in combination with ADM inhibited tumor growth and increased the survival of SNK-6/ADM xenograft mice. In conclusion, our findings suggest that IL-6 can inhibit the upregulation of ABCC4 and inactivate the JAK2/STAT3/NF-κB/P65 pathway to sensitize NK/T-cell lymphoma to ADM, indicating that combination therapy with IL-6 and other chemotherapeutic drugs may be effective in reversing acquired resistance in nasal NK/T-cell lymphoma.

IL-6 promotes nuclear translocation of HIF-1α to aggravate chemoresistance of ovarian cancer cells

The inflammatory milieu in tumor modulates the resistance to the conventional antitumoral therapies. Interleukin-6 (IL-6), a pleiotropic pro-inflammatory cytokine and a crucial mediator of tumor development, has been targeted as a therapeutic strategy to overcome chemoresistance in the treatment of tumors. The protein levels and nuclear translocation of HIFs (hypoxia-inducible factors), such as HIF-1α, are linked to the drug resistance of tumor cells. However, whether IL-6 promotes the nuclear translocation of HIF-1α and the related mechanism remain to be investigated. We applied two ovarian cancer (OvCa) cell lines, A2780 cells and SKOV3 cells for the in vivo and in vitro studies. We found that IL-6 up-regulates the HIF-1α expression via the signal transducer and activator of transcription 3 (STAT3) signaling under hypoxia in either endogenous or exogenous way, and then we proved that IL-6 enhances the transcriptional activity of HIF-1α via the STAT3 signaling. Further mechanism research revealed that IL-6 promotes the nuclear translocation of HIF-1α through the STAT3 signaling under hypoxia. Proliferation assay and apoptosis assay were applied and proved that IL-6 enhances the chemoresistance of OvCa cells against cisplatin through the upregulation of HIF-1α via the STAT3 signaling in vitro. The In vivo studies confirmed the effect of IL-6 in increasing the chemoresistance of OvCa cells against cisplatin through the IL-6/STAT3/HIF-1α loop in the animal models. Our data elucidates the explicit mechanism of IL-6/STAT3/HIF-1α loop in OvCa and also provides new insights into the development of different approaches for the inflammation-induced and hypoxia-induced resistance in tumor therapies.

Flufenoxuron suppresses the proliferation of testicular cells by targeting mitochondria in mice

Flufenoxuron is a benzoylurea pesticide that is used to eradicate insects and acarids in the farmland. Even though it specifically works on target animals, the possibilities of its bioaccumulation and harmful effects on non-target animals cannot be denied. As the usage and application of pesticides increases, exposure to them also increases through ingestion of food residues, inhalation, or dermal contact. Pesticides could also be considered as endocrine disruptor chemicals; however, the reproductive toxicity and cellular mechanisms of flufenoxuron have not been identified. Our results indicate that flufenoxuron inhibits cellular proliferation and hampers calcium homeostasis, especially by targeting mitochondria. We also confirmed the induction of endoplasmic reticulum (ER) stress and ER-mitochondrial contact signaling. Using pharmacological inhibitors, we also observed that the mitogen-activated protein kinase and Akt signaling pathways were upregulated by flufenoxuron. Further, by oral administration of flufenoxuron (100 mg/kg/bw) to C57BL/6 male mice, we observed transcriptional changes in the testis-related genes. Collectively, we demonstrated that flufenoxuron inhibits cell proliferation and alters gene expression in mouse testis cells and induces testicular dysfunction in mice. These results indicate that flufenoxuron may be harmful to male reproduction and fertility in the early stages of pregnancy.

Mechanisms of long non-coding RNA function in colorectal cancer tumorigenesis

Colorectal cancer (CRC) is one of the most common cancers globally. Although a variety of CRC screening methods have been developed, many patients are diagnosed at advanced stages of CRC with tumor invasion and distance metastasis. Several studies have suggested the long noncoding RNAs (lncRNAs) as one of the main contributors in CRC tumorigenesis, although the exact underlying mechanism of lncRNAs in CRC is still unknown. Numerous studies have indicated aberrant expression of lncRNAs in CRC through different modes of action such as cell proliferation, apoptosis, cell cycle, DNA repair response, drug-resistance, migration, and metastasis. Furthermore, lncRNA polymorphisms can influence the risk of CRC development. Accordingly, lncRNAs can be served as promising diagnostic or prognostic biomarkers and also desired therapeutic targets affecting the outcome of patients with CRC. In this review, we summarized the updated and novel evidence that identifies different roles of lncRNAs in the tumorigenesis of CRC.

Apigenin induces apoptosis and counteracts cisplatin-induced chemoresistance via Mcl-1 in ovarian cancer cells

Ovarian cancer (OC) is one of the prominent causes of mortality in female patients diagnosed with gynecologic malignancies. While it has previously been demonstrated that apigenin inhibits cell growth in colon and breast cancer cells, the effect of apigenin in OC cells is not fully understood. Therefore, the aim of the present study was to investigate the impact of apigenin on cell death and resistance to cisplatin in OC cells. It was found that apigenin inhibited proliferation, hindered cell cycle progression and promoted SKOV3 cell apoptosis. Moreover, these effects were also observed in cisplatin-resistant SKOV3/DDP cells. Furthermore, apigenin reduced the mitochondrial transmembrane potential, and elevated the ratios of cleaved caspase-3/caspase-3 and Bax/Bcl-2 in the two cell types. Reverse transcription-quantitative PCR and western blotting results demonstrated that apigenin significantly downregulated Mcl-1 at the transcriptional and translational levels in SKOV3 and SKOV3/DDP cells, which was responsible for its cytotoxic functions and chemosensitizing effects. Collectively, the present results identified the impact of apigenin on OC cell death and resistance to cisplatin, and the potential molecular mechanisms. However, additional studies are required to further elucidate the underlying mechanisms.

Novel Approaches and Challenges of Discovery of Exosite Modulators of a Disintegrin and Metalloprotease 10

A disintegrin and metaproteinase 10 is an important target for multiple therapeutic areas, however, despite drug discovery efforts by both industry and academia no compounds have reached the clinic so far. The lack of enzyme and substrate selectivity of developmental drugs is believed to be a main obstacle to the success. In this review, we will focus on novel approaches and associated challenges in discovery of ADAM10 selective modulators that can overcome shortcomings of previous generations of compounds and be translated into the clinic.

EGFR Blockade Reverses Cisplatin Resistance in Human Epithelial Ovarian Cancer Cells

Background:

EOC is one of the most lethal gynecological malignancy worldwide. Although the majority of EOC patients achieve clinical remission after induction therapy, over 80% relapse and succumb to the chemoresistant disease. Previous investigations have demonstrated the association of EGFR with resistance to cytotoxic chemotherapies, hormone therapy, and radiotherapy in the cancers. These studies have highlighted the role of EGFR as an attractive therapeutic target in cisplatin-resistant EOC cells.

Methods:

The human ovarian cell lines (SKOV3 and OVCAR3) were cultured according to ATCC recommendations. The MTT assay was used to determine the chemosensitivity of the cell lines in exposure to cisplatin and erlotinib. The qRT-PCR was applied to analyze the mRNA expression of the desired genes.

Results:

Erlotinib in combination with cisplatin reduced the cell proliferation in the chemoresistant EOC cells in comparison to monotherapy of the drugs (p < 0.05). Moreover, erlotinib/cisplatin combination synergistically decreased the expression of anti-apoptotic and also increased pro-apoptotic genes expression (p < 0.05). Cisplatin alone could increase the expression of MDR genes. The data suggested that EGFR and cisplatin drive chemoresistance in the EOC cells through MEKK signal transduction as well as through EGFR/MEKK pathways in the cells, respectively.

Conclusion:

Our findings propose that EGFR is an attractive therapeutic target in chemoresistant EOC to be exploited in translational oncology, and erlotinib/cisplatin combination treatment is a potential anti-cancer approach to overcome chemoresistance and inhibit the proliferation of the EOC cells.

Metabolism of Estrogens: Turnover Differs Between Platinum-Sensitive and -Resistant High-Grade Serous Ovarian Cancer Cells

High-grade serous ovarian cancer (HGSOC) is currently treated with cytoreductive surgery and platinum-based chemotherapy. The majority of patients show a primary response; however, many rapidly develop drug resistance. Antiestrogens have been studied as low toxic treatment options for HGSOC, with higher response rates in platinum-sensitive cases. Mechanisms for this difference in response remain unknown. Therefore, the present study investigated the impact of platinum resistance on steroid metabolism in six established HGSOC cell lines sensitive and resistant against carboplatin using a high-resolution mass spectrometry assay to simultaneously quantify the ten main steroids of the estrogenic metabolic pathway. An up to 60-fold higher formation of steroid hormones and their sulfated or glucuronidated metabolites was observed in carboplatin-sensitive cells, which was reversible by treatment with interleukin-6 (IL-6). Conversely, treatment of carboplatin-resistant cells expressing high levels of endogenous IL-6 with the monoclonal anti-IL-6R antibody tocilizumab changed their status to “platinum-sensitive”, exhibiting a decreased IC₅₀ value for carboplatin, decreased growth, and significantly higher estrogen metabolism. Analysis of these metabolic differences could help to detect platinum resistance in HGSOC patients earlier, thereby allowing more efficient interventions.

Metformin and ovarian cancer survival: is there a rational warrant for belief?

Metformin (MF) represents the first-line drug used to treat type 2 diabetes. Recently, MF has also been reported to be a potential and promising anti-cancer agent for some gynecological cancers' prevention. MF, as an anti-tumorigenic factor, may reduce the chance of developing ovarian cancer by targeting IL-6. By acting on IL-6 expression, metformin might have a positive impact on the main molecular pathways strictly connected with pathogenesis and biological features of ovarian cancer. Further investigation is warranted to better define the use of MF as a possible treatment option in the fight against ovarian cancer.