NF-κB signaling plays irreplaceable roles in cisplatin-induced bladder cancer chemoresistance and tumor progression

Identification of a cisplatin resistant-based prognostic immune related gene signature in MIBC

Cisplatin resistance plays a significant role in the dismal prognosis and progression of muscle-invasive bladder cancer (MIBC). However, the strategies to predict prognosis and cisplatin resistance are inefficient, and it remains unclear whether cisplatin resistance is associated with tumor immunity. In this study, we integrated the transcriptional data from cisplatin-resistant cell lines and a TCGA-MIBC cohort to establish cisplatin-resistance-related cluster classification and a cisplatin-resistance-related gene risk score (CRRGRS). Kaplan-Meier survival curves showed that compared with those in low CRRGRS group, MIBC patients belonging to high CRRGRS group had worse prognosis in TCGA-MIBC cohort and external GEO cohorts. Meanwhile, CRRGRS was able to help forecast chemotherapy and immunotherapy response of MIBC patients in the TGCA cohort and IMvigor210 cohort. Moreover, compared with the low CRRGRS group, the high CRRGS group possessed a relatively immunosuppressive "cold tumor" phenotype with a higher tumor immune dysfunction and exclusion (TIDE) score, ESTIMATE score, stromal score and immune score and a lower immunophenoscore (IPS) score. The upregulated expression levels of immune checkpoint genes, including PD-1, PD-L1 and CTLA4, in the high CRRGRS group also further indicated that a relative immunosuppressive tumor microenvironment may exist in MIBC patients belonging to high CRRGRS group. In addition, we integrated CRRGRS and clinical characteristics with prognostic value to develop a nomogram, which could help forecast overall survival of MIBC patients. Furthermore, DIAPH3 was identified as a regulator of proliferation and cisplatin resistance in MIBC. The expression of DIAPH3 was increased in cisplatin-resistant cell lines and chemotherapy-unsensitive people. Further mechanism exploration revealed that DIAPH3 facilitated tumor proliferation and cisplatin resistance by regulating the NF-kB and epithelial-mesenchymal transition (EMT) pathways. In conclusion, the comprehensive investigations of CRRGRS increased the understanding of cisplatin resistance and provided promising insights to restrain tumor growth and overcome chemoresistance by targeting DIAPH3.

Tumorigenic effects of human mesenchymal stromal cells and fibroblasts on bladder cancer cells

Background

Patients with muscle-invasive bladder cancer face a poor prognosis due to rapid disease progression and chemoresistance. Thus, there is an urgent need for a new therapeutic treatment. The tumor microenvironment (TME) has crucial roles in tumor development, growth, progression, and therapy resistance. TME cells may also survive standard treatment of care and fire up disease recurrence. However, whether specific TME components have tumor-promoting or tumor-inhibitory properties depends on cell type and cancer entity. Thus, a deeper understanding of the interaction mechanisms between the TME and cancer cells is needed to develop new cancer treatment approaches that overcome therapy resistance. Little is known about the function and interaction between mesenchymal stromal cells (MSC) or fibroblasts (FB) as TME components and bladder cancer cells.

Methods

We investigated the functional impact of conditioned media (CM) from primary cultures of different donors of MSC or FB on urothelial carcinoma cell lines (UCC) representing advanced disease stages, namely, BFTC-905, VMCUB-1, and UMUC-3. Underlying mechanisms were identified by RNA sequencing and protein analyses of cancer cells and of conditioned media by oncoarrays.

Results

Both FB- and MSC-CM had tumor-promoting effects on UCC. In some experiments, the impact of MSC-CM was more pronounced. CM augmented the aggressive phenotype of UCC, particularly of those with epithelial phenotype. Proliferation and migratory and invasive capacity were significantly increased; cisplatin sensitivity was reduced. RNA sequencing identified underlying mechanisms and molecules contributing to the observed phenotype changes. NRF2 and NF-κB signaling was affected, contributing to improved cisplatin detoxification. Likewise, interferon type I signaling was downregulated and regulators of epithelial mesenchymal transition (EMT) were increased. Altered protein abundance of CXCR4, hyaluronan receptor CD44, or TGFβ-signaling was induced by CM in cancer cells and may contribute to phenotypical changes. CM contained high levels of CCL2/MCP-1, MMPs, and interleukins which are well known for their impact on other cancer entities.

Conclusions

The CM of two different TME components had overlapping tumor-promoting effects and increased chemoresistance. We identified underlying mechanisms and molecules contributing to the aggressiveness of bladder cancer cells. These need to be further investigated for targeting the TME to improve cancer therapy.

TFAP2C Knockdown Sensitizes Bladder Cancer Cells to Cisplatin Treatment via Regulation of EGFR and NF-κB

Simple Summary

Bladder cancer (BCa) is considered one of the most common neoplasms of the urology system. Cisplatin-based chemotherapy has been the primary treatment for patients with advanced or metastatic BCa. Nevertheless, cisplatin resistance often limits the treatment of bladder cancer. We expect to find approaches to improve the therapeutic efficacy of cisplatin in bladder cancer. In recent years, many studies have shown that transcription factor AP-2 gamma (TFAP2C) acts as a key player in cancer development and and its expression level is closely related to the sensitivity of tumors to cisplatin. Our study investigated whether TFAP2C affects the sensitivity of BCa cells to cisplatin and the possible mechanisms. We found that TFAP2C expression was significantly upregulated in most BCa tissues compared to adjacent normal tissues. The present study confirmed that TFAP2C knockdown enhanced the anti-tumor effects of cisplatin by decreasing cisplatin-induced activation levels of epidermal growth factor receptor (EGFR) and nuclear factor kappaB (NF-κB). Specifically, this study provides a novel approach to improve the efficacy of cisplatin.

Abstract

Cisplatin is the first-line chemotherapy for advanced or metastatic bladder cancer. Nevertheless, approximately half of patients with BCa are insensitive to cisplatin therapy or develop cisplatin resistance during the treatment process. Therefore, it is especially crucial to investigate ways to enhance the sensitivity of tumor cells to cisplatin. Transcription factor AP-2 gamma (TFAP2C) is involved in cancer development and chemotherapy sensitivity. However, its relationship with chemotherapy has not been studied in BCa. In this study, we aimed to investigate the therapeutic potential of TFAP2C in human BCa. Results based on TCGA (The Cancer Genome Atlas), GTEx (The Genotype-Tissue Expression) and GEO (Gene Expression Omnibus) data showed that TFAP2C expression was upregulated in BCa tissues and that its high expression was associated with poor prognosis. Meanwhile, we demonstrated the overexpression of TFAP2C in BCa clinical specimens. Subsequently, in vitro, we knocked down TFAP2C in BCa cells and found that TFAP2C knockdown further increased cell cycle arrest and apoptosis caused by cisplatin. In addition, the inhibitory effect of cisplatin on BCa cell migration and invasion was enhanced by TFAP2C knockdown. Our data indicated that cisplatin increased epidermal growth factor receptor (EGFR) and nuclear factor-kappaB (NF-κB) activation levels, but TFAP2C knockdown suppressed this effect. Finally, in vivo data further validated these findings. Our study showed that TFAP2C knockdown affected the activation levels of EGFR and NF-κB and enhanced the anti-tumor effects of cisplatin in vivo and in vitro. This provides a new direction to improve the efficacy of traditional cisplatin chemotherapy.

Investigating the Role of Quercetin in Increasing the Rate of Cisplatin-Induced Apoptosis Via the NF-κB Pathway in MG-63 Cancer Cells

INTRODUCTION

Numerous studies suggest that the co-treatment of chemotherapeutic agents with flavonoids such as Quercetin (Que) may enhance tumor cells' susceptibility to these agents. Hence, in the current study, we investigated Que's role in combination with Cisplatin to promote cell apoptosis by focusing on the NF-κB signaling pathway in the osteosarcoma cell lines.

METHODS

The Que, Cisplatin, and their combination's general cytotoxicity effects were evaluated using an MTT assay for 72 hrs. The protein expression levels of NF-κB were detected by an enzyme-linked immunosorbent assay (ELISA) Kit. Flow cytometry was used to evaluate cell apoptosis.

RESULTS

Que considerably elevated the cytotoxicity of Cisplatin (P<0.05). Que also dramatically down-regulated the expression levels of NF-κB in MG-63 cells compared to mono-treatment (P<0.05). Besides, Que promotes cisplatin-induced apoptosis in MG-63 cells.

CONCLUSION

Our study's findings provide an exact point in the field of adjuvant therapy in osteosarcoma. In other words, this study could provide new insights into a better understanding of the role of Que in elevating cisplatin-induced apoptosis with NF-κB down-regulation.

NF-κB as a regulator of cancer metastasis and therapy response: A focus on epithelial-mesenchymal transition

Metastasis of tumor cells is a complex challenge and significantly diminishes the overall survival and prognosis of cancer patients. The epithelial-to-mesenchymal transition (EMT) is a well-known mechanism responsible for the invasiveness of tumor cells. A number of molecular pathways can regulate the EMT mechanism in cancer cells and nuclear factor-kappaB (NF-κB) is one of them. The nuclear translocation of NF-κB p65 can induce the transcription of several genes involved in EMT induction. The present review describes NF-κB and EMT interaction in cancer cells and their association in cancer progression. Due to the oncogenic role NF-κB signaling, its activation enhances metastasis of tumor cells via EMT induction. This has been confirmed in various cancers including brain, breast, lung and gastric cancers, among others. The ZEB1/2, transforming growth factor-β, and Slug as inducers of EMT undergo upregulation by NF-κB to promote metastasis of tumor cells. After EMT induction driven by NF-κB, a significant decrease occurs in E-cadherin levels, while N-cadherin and vimentin levels undergo an increase. The noncoding RNAs can potentially also function as upstream mediators and modulate NF-κB/EMT axis in cancers. Moreover, NF-κB/EMT axis is involved in mediating drug resistance in tumor cells. Thus, suppressing NF-κB/EMT axis can also promote the sensitivity of cancer cells to chemotherapeutic agents.

The role of tumour microenvironment-driven miRNAs in the chemoresistance of muscle-invasive bladder cancer-a review

Successful treatment for muscle-invasive bladder cancer is challenged by the ability of cancer cells to resist chemotherapy. While enormous progress has been made toward understanding the divergent molecular mechanisms underlying chemoresistance, the heterogenous interplay between the bladder tumour and its microenvironment presents significant challenges in comprehending the occurrence of chemoresistance. The last decade has seen exponential interest in the exploration of microRNA (miRNA) as a tool in the management of chemoresistance. In this review, we highlight the miRNAs involved in the tumour microenvironment crosstalk that contributes to the chemoresistance in bladder cancer. Decrypting the role of miRNAs in the interplay beholds scope for future clinical translational application in managing the long-standing concerns of chemoresistance in muscle-invasive bladder cancer.

CDKN3 Overcomes Bladder Cancer Cisplatin Resistance via LDHA-Dependent Glycolysis Reprogramming

Background

Aerobic glycolysis plays an important role in bladder cancer (BLCA) progression and chemoresistance. Cyclin-dependent kinase inhibitor-3 (CDKN3), a dual-specificity protein tyrosine phosphatase, has aberrant upregulation in multiple cancer types and is associated with tumorigenesis. However, the role of CDKN3 in BLCA progression and glycolysis has not been elucidated.

Purpose

In this study, we investigated the effect and underlying mechanisms of CDKN3 on bladder cancer chemoresistance.

Results

This study confirmed that CDKN3 was overexpressed in BLCA tissues and promoted proliferation and migration. Additionally, our results showed a CDKN3-dependent mechanism on chemoresistance; chemoresistance cells were transformed into chemosensitivity cells by CDKN3 knockdown. Additionally, we showed that CDKN3 knockdown decreased glycolysis by inhibiting LDHA expression in BLCA chemoresistance cells. The results also proved that LDHA was an important mediator of CDKN3-regulated BLCA resistance. LDHA overexpression reversed glycolysis inhibition and chemosensitivity induced by CDKN3 downregulation.

Conclusion

These data collectively identified a vital role of CDKN3 in glycolysis and chemoresistance by regulating LDHA expression in BLCA cells, providing a possible therapeutic strategy for treating BLCA.

PR-619, a General Inhibitor of Deubiquitylating Enzymes, Diminishes Cisplatin Resistance in Urothelial Carcinoma Cells through the Suppression of c-Myc: An In Vitro and In Vivo Study

Cisplatin-based chemotherapy is the standard treatment for bladder urothelial carcinoma (UC). Most patients experience chemoresistance, the primary cause of treatment failure, which leads to disease relapse. The underlying mechanism of chemoresistance involves reduced apoptosis. In this study, we investigated the antitumor effect of the deubiquitylating enzyme inhibitor PR-619 in cisplatin-resistant bladder UC. Deubiquitinase (ubiquitin-specific protease 14 (USP14) and USP21) immunohistochemical staining demonstrated that deubiquitination is related to chemoresistance in patients with metastatic UC and may be a target for overcoming chemoresistance. Cytotoxicity and apoptosis were assessed using fluorescence-activated flow cytometry and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay, and PR-619 was found to enhance the cytotoxic and apoptotic effects of cisplatin in cisplatin-resistant T24/R cells. Mitigated cisplatin chemoresistance was associated with the concurrent suppression of c-Myc expression in T24/R cells. Moreover, the expression of c-Myc was upregulated in human bladder UC specimens from patients with chemoresistance. Experiments in a xenograft nude mouse model confirmed that PR-619 enhanced the antitumor effects of cisplatin. These results are promising for the development of therapeutic strategies to prevent UC chemoresistance through the combined use of chemotherapeutic agents/deubiquitination inhibitors (PR-619) by targeting the c-Myc pathway.

Synthetic Artificial Long Non-coding RNA Shows Higher Efficiency in Specific Malignant Phenotype Inhibition Compared to the CRISPR/Cas Systems

Objective: Both oncogenic transcription factors (TFs) and microRNAs (miRNAs) play an important regulator in human cancer by transcriptional and post-transcriptional regulation, respectively. These phenomena raise questions about the ability of artificial device to regulate miRNAs and TFs simultaneously. In this study, we aimed to construct an artificial long non-coding RNA, “alncRNA,” which imitated CRISPR/Cas systems and to illuminate its therapeutic effects in bladder cancer cell lines. At the same time, we also compared the efficiency of alncRNA and CRISPR/Cas systems in regulating gene expression.

Study Design and Methods: Based on engineering principles of synthetic biology, we combined tandem arrayed cDNA sequences of aptamer for TFs with tandem arrayed cDNA copies of binding sites for the miRNAs to construct alncRNA. In order to prove the utility of this platform, we chose β -catenin, NF-κB, miR-940, and miR-495 as the functional targets and used the bladder cancer cell lines 5637 and T24 as the test models. Real-time Quantitative PCR (qPCR), dual-luciferase assay and relative phenotypic experiments were applied to severally test the expression of relative gene and therapeutic effects of our devices.

Result: Dual-luciferase assay indicated alncRNA could inhibit transcriptional activity of TFs. What’s more, the result of qPCR showed that expression levels of the relative TFs target genes and miRNAs were reduced by corresponding alncRNA and the inhibitory effect was better than CRIPSR dCas9-KRAB. By functional experiments, decreased cell proliferation, increased apoptosis, and motility inhibition were observed in alncRNA-infected bladder cells.

Conclusion: In summary, our synthetic devices indeed function as anti-tumor regulator, which synchronously accomplish transcriptional and post-transcriptional regulation in bladder cancer cell and show higher efficiency in specific malignant phenotype inhibition compared to the CRISPR/Cas systems. Most importantly, Anti-cancer effects were induced by the synthetic alncRNA in the bladder cancer lines. Our devices, therefore, provides a novel strategy for cancer therapy and could be a useful “weapon” for cancer cell.

Bladder cancer-derived interleukin-1 converts the vascular endothelium into a pro-inflammatory and pro-coagulatory surface

Background

Bladder cancer cells orchestrate tumour progression by pro-inflammatory cytokines. Cytokines modulate the local tumour microenvironment and increase the susceptibility of tumour distant tissues for metastasis. Here, we investigated the impact of human bladder cancer cell derived factors on the ability to modulate and activate human vascular endothelial cells.

Methods

The pro-inflammatory and pro-coagulatory potential of four different bladder cancer cell lines was accessed by qRT-PCR arrays and ELISA. Modulation and activation of endothelial cells was studied in microfluidic devices. Clinical relevance of our findings was confirmed by immune histology in tissue samples of bladder cancer patients and public transcriptome data.

Results

The unbalanced ratio between interleukin (IL)-1 and IL-1 receptor antagonist (IL-1ra) in the secretome of bladder cancer cells converted the quiescent vascular endothelium into a pro-adhesive, pro-inflammatory, and pro-coagulatory surface. Microfluidic experiments showed that tumour cell induced endothelial cell activation promoted leukocyte recruitment and platelet adhesion. Human bladder cancer tissue analysis confirmed that loss of IL-1ra and elevated IL-1 expression was associated with enhanced cancer progression.

Conclusions

Our data indicate that IL-1 and IL-1ra were dysregulated in bladder cancer and could facilitate tumour dissemination through endothelial cell activation. Targeting the IL-1/IL-1ra axis might attenuate tumour-mediated inflammation and metastasis formation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07548-z.

The role of long non-coding RNAs in mediating chemoresistance by modulating autophagy in cancer

Cancer is a complex process in which protein-coding and non-coding genes play essential roles. Long noncoding RNAs (lncRNAs), as a subclass of noncoding genes, are implicated in various cancer processes including growth, proliferation, metastasis, and angiogenesis. Due to presence in body fluids such as blood and urine, lncRNAs have become novel biomarkers in cancer detection, diagnosis, progression, and therapy response. Remarkably, increasing evidence has verified that lncRNAs play essential roles in chemoresistance by targeting different signalling pathways. Autophagy, a highly conserved process in response to environmental stresses such as starvation and hypoxia, plays a paradoxical role in inducing resistance or sensitivity to chemotherapy agents. In this regard, we reviewed chemoresistance, the role of lncRNAs in cancer, and the role of lncRNAs in chemoresistance by modulating autophagy.

Astragaloside IV enhanced carboplatin sensitivity in prostate cancer by suppressing AKT/NF-κB signaling pathway

In our study, we explored the effect of astragaloside IV (AgIV) on carboplatin chemotherapy in prostate cancer cell lines in vitro and in vivo. Cell viability assay, colony formation assay, flow cytometry, Western blot, immunohistochemistry, immunofluorescence, and tumor xenograft growth assay were conducted. We found that AgIV significantly decreased the half-maximal inhibitory concentration of carboplatin in prostate cancer cell lines LNCap and PC-3. Moreover, AgIV enhanced the effect of carboplatin in suppressing colony formation and inducing cell apoptosis. A low-dose carboplatin treatment upregulated N-cadherin and Vimentin expression and downregulated E-cadherin expression, but this effect was abolished by combining with AgIV. Carboplatin treatment increased the levels of p-AKT and p-p65 and decreased p-IκBα, but AgIV treatment suppressed this. In addition, AgIV synergized with carboplatin to suppress tumor xenograft growth of PC-3 cells, and decreased pAKT and p-p65 levels in vivo. Our results suggested that AgIV enhanced carboplatin sensitivity in prostate cancer cell lines by suppressing AKT/NF-κB signaling, thus suppressed epithelial-mesenchymal transition induced by carboplatin. Our findings provided a new mechanism for AgIV in overcoming drug resistance of platinum-based chemotherapy and suggested a potential combination therapy of AgIV and carboplatin in prostate cancer.

Overexpression of ABCC2 and NF-Κβ/p65 with Reduction in Cisplatin and 4OH-Tamoxifen Sensitivity in MCF-7 Breast Cancer Cells: The Influence of TNF-α

Background: TNF-α, as a pro-inflammatory cytokine in the tumor microenvironment is able to regulate the expression and function of various ATP binding cassette (ABC) transporters involved in clinical drug resistance and among them, ABCC2 transporter is represented to contribute to cancer multidrug resistance (MDR) by drug efflux. Methods: In this study, we aimed to evaluate the effects of TNF-α and/or E2 (17β-estradiol) on the mRNA and protein expression levels of ABCC2 and NF-κB (p65) transcription factor in estrogen receptor positive (ER+) MCF-7 cells by QRT-PCR and Western blot analysis. Also, we used MTT assay to study the cell sensitivity against the active form of tamoxifen (4OH-TAM), a hypothetical substrate and Cisplatin (Cis), a well-known substrate for ABCC2 used in endocrine and chemo-therapy of breast cancers, respectively. Data were analyzed by one-way ANOVA and Tukey tests. Significance was considered in P-values < 0.05. Results: The expression levels of ABCC2 and the active form of NF-κB (p65) were significantly increased following 20-day concomitant treatment with TNF-α and E2, compared to untreated cells as control. Also, the viability assay showed that 20-day TNF-α+E2 treatment led to more sensitivity reduction of MCF-7 cells to Cis and 4OH-TAM compared to E2-treated and untreated cells. Conclusion: Based on our findings, there is a positive correlation between ABCC2 overexpression, over-activity of NF-ҡB/p65 and decreasing the sensitivity of MCF-7 cells to Cis and 4OH-TAM following TNF-α treatment in MCF-7 cells. Further experiments are needed to elucidate possible mechanistic relationship of these findings and their clinical significance in order to circumvent the drug-resistance in breast tumors.

Chemotherapy-Induced IL8 Upregulates MDR1/ABCB1 in Tumor Blood Vessels and Results in Unfavorable Outcome

Tumor endothelial cells (TEC) lining tumor blood vessels actively contribute to tumor progression and metastasis. In addition to tumor cells, TEC may develop drug resistance during cancer treatment, allowing the tumor cells to survive chemotherapy and metastasize. We previously reported that TECs resist paclitaxel treatment via upregulation of ABCB1. However, whether TEC phenotypes are altered by anticancer drugs remains to be clarified. Here, we show that ABCB1 expression increases after chemotherapy in urothelial carcinoma cases. The ratio of ABCB1-positive TEC before and after first-line chemotherapy in urothelial carcinoma tissues (n = 66) was analyzed by ABCB1 and CD31 immunostaining. In 42 cases (64%), this ratio increased after first-line chemotherapy. Chemotherapy elevated ABCB1 expression in endothelial cells by increasing tumor IL8 secretion. In clinical cases, ABCB1 expression in TEC correlated with IL8 expression in tumor cells after first-line chemotherapy, leading to poor prognosis. In vivo, the ABCB1 inhibitor combined with paclitaxel reduced tumor growth and metastasis compared with paclitaxel alone. Chemotherapy is suggested to cause inflammatory changes in tumors, inducing ABCB1 expression in TEC and conferring drug resistance. Overall, these findings indicate that TEC can survive during chemotherapy and provide a gateway for cancer metastasis. Targeting ABCB1 in TEC represents a novel strategy to overcome cancer drug resistance. SIGNIFICANCE: These findings show that inhibition of ABCB1 in tumor endothelial cells may improve clinical outcome, where ABCB1 expression contributes to drug resistance and metastasis following first-line chemotherapy.

Bladder neoplasms and NF-κB: an unfathomed association

Introduction: Bladder cancer is the second most common genitourinary tract cancer and is often recurrent and/or chemoresistant after tumor resection. Cigarette smoking, exposure to aromatic amines, and chronic infection/inflammation are bladder cancer risk factors. NF-κB is a transcription factor that plays a critical role in normal physiology and bladder cancer. Bladder cancer patients have constitutively active NF-κB triggered by pro-inflammatory cytokines, chemokines, and hypoxia, augmenting carcinogenesis and progression.Areas covered: NF-κB orchestrates protein interactions (PTEN, survivin, VEGF), regulation (CYLD, USP13) and gene expression (Trp 53) resulting in bladder cancer progression, recurrence and resistance to therapy. This review focuses on NF-κB in bladder inflammation, cancer and resistance to therapy.Expert opinion: NF-κB and bladder cancer necessitate further research to develop better diagnostic and treatment regimens that address progression, recurrence and resistance to therapy. NF-κB is a master regulator that can act with or on minimally one cancer hallmark gene or protein, leading to bladder cancer progression (Tp53, PTEN, VEGF, HMGB1, CYLD, USP13), recurrence (PCNA, BcL-2, JUN) and resistance to therapy (P-gp, twist, SETD6). Thus, an understanding of bladder cancer in relation to NF-κB will offer improved strategies and efficacious targeted therapies resulting in minimal progression, recurrence and resistance to therapy.

The Drug-Resistance Mechanisms of Five Platinum-Based Antitumor Agents

Platinum-based anticancer drugs, including cisplatin, carboplatin, oxaliplatin, nedaplatin, and lobaplatin, are heavily applied in chemotherapy regimens. However, the intrinsic or acquired resistance severely limit the clinical application of platinum-based treatment. The underlying mechanisms are incredibly complicated. Multiple transporters participate in the active transport of platinum-based antitumor agents, and the altered expression level, localization, or activity may severely decrease the cellular platinum accumulation. Detoxification components, which are commonly increasing in resistant tumor cells, can efficiently bind to platinum agents and prevent the formation of platinum–DNA adducts, but the adducts production is the determinant step for the cytotoxicity of platinum-based antitumor agents. Even if adequate adducts have formed, tumor cells still manage to survive through increased DNA repair processes or elevated apoptosis threshold. In addition, autophagy has a profound influence on platinum resistance. This review summarizes the critical participators of platinum resistance mechanisms mentioned above and highlights the most potential therapeutic targets or predicted markers. With a deeper understanding of the underlying resistance mechanisms, new solutions would be produced to extend the clinical application of platinum-based antitumor agents largely.

ZSCAN16 promotes proliferation, migration and invasion of bladder cancer via regulating NF-kB, AKT, mTOR, P38 and other genes

BACKGROUND

As one of the most common genitourinary malignancies worldwide, bladder cancer affects about 3.4 million people globally, with 430,000 new cases a year since 2015. Despite the advances in bladder cancer diagnosis and therapy, there has been little progress in the patients' overall survival in nearly 30 years. Therefore, investigating novel molecular therapeutic targets is required to gain insight into the tumorigenesis of bladder cancer, which ultimately may be used to develop more effective therapeutic strategies.

METHODS

Herein, we used gene knockdown in vitro and in vivo to unveil the unknown roles of ZSCAN16 in bladder cancer. Afterward, to decipher the unknown regulatory role of ZSCAN16 in tumor progression, we verified that a bunch of genes including NF-κB, AKT, mTOR, and P38 were the key downstream regulators of ZSCAN16 by western blot and rescue experiments.

RESULTS

We found high expression of ZSCAN16 transcripts in bladder cancer cells and tumor samples from the TCGA database and tissue microarray bank, demonstrated in correlation with poor prognosis for bladder cancer patients. The in vitro experiments indicated that the silencing of ZSCAN16 by shRNA lentivirus promoted apoptosis and inhibited proliferation, colony formation, as well as migration and invasion in T24 cells. By investigating the signaling pathways, we proved ZSCAN16 play a novel role as oncogenic gene in bladder cancer by regulating NF-κB, AKT, mTOR, P38 and other genes. Furthermore, the in vivo experiments identified that ZSCAN16 knockdown retarded the tumor growth in nude mice.

CONCLUSIONS

In summary, these findings revealed that ZSCAN16 is a potential novel oncogene in the development and progression of bladder cancer. This study will shed light on developing novel therapeutic targets in the future treatment of bladder cancer.

RETRACTED: Triptolide inhibits viability and migration while promotes apoptosis in nephroblastoma cells by regulation of miR-193b-3p

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief as panels from Figure 1E appear similar to panels from Figures 1G, 3D and 5D. Given the comments of Dr Elisabeth Bik regarding this article “This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

The Combination of the CIGB-300 Anticancer Peptide and Cisplatin Modulates Proteins Related to Cell Survival, DNA Repair and Metastasis in a Lung Cancer Cell Line Model

Background:

CIGB-300 is a pro-apoptotic peptide that abrogates CK2-mediated phosphorylation, and can elicit synergistic interaction in vitro and in vivo when combined with certain anticancer drugs.

Objective:

The combination of CIGB-300 with cisplatin is studied through data mining and expressionbased proteomics to reveal the molecular basis of this interaction. Cisplatin resistance-associated proteins, which have also been reported as CK2 substrates, were first identified by bioinformatic analyses.

Methods:

Data from these analyses suggested that the cisplatin resistance phenotype could be directly improved by inhibiting CK2 phosphorylation on specific substrates. Furthermore, 157 proteins were differentially modulated on the NCI-H125 lung cancer cell line in response to CIGB-300, cisplatin or both drugs as determined by LC-MS/MS.

Results:

The expression of 28 cisplatin resistance-associated proteins was changed when cisplatin was combined with CIGB-300. Overall, the proteins identified are also related to cell survival, cell proliferation and metastasis. Furthermore, the CIGB-300 regulated proteome revealed proteins that were initially involved in the mechanism of action of CIGB-300 and cisplatin as single agents.

Conclusion:

This is the first report describing the protein array modulated by combining CIGB-300 and cisplatin that will support the rationale for future clinical settings based on a multi-target cancer therapy.

Targeting Oncogenic Nuclear Factor Kappa B Signaling with Redox-Active Agents for Cancer Treatment

SIGNIFICANCE

Nuclear factor kappa B (NF-κB) signaling is essential under physiologically relevant conditions. However, aberrant activation of this pathway plays a pertinent role in tumorigenesis and contributes to resistance. Recent Advances: The importance of the NF-κB pathway means that its targeting must be specific to avoid side effects. For many currently used therapeutics and those under development, the ability to generate reactive oxygen species (ROS) is a promising strategy.

CRITICAL ISSUES

As cancer cells exhibit greater ROS levels than their normal counterparts, they are more sensitive to additional ROS, which may be a potential therapeutic niche. It is known that ROS are involved in (i) the activation of NF-κB signaling, when in sublethal amounts; and (ii) high levels induce cytotoxicity resulting in apoptosis. Indeed, ROS-induced cytotoxicity is valuable for its capabilities in killing cancer cells, but establishing the potency of ROS for effective inhibition of NF-κB signaling is necessary. Indeed, some cancer treatments, currently used, activate NF-κB and may stimulate oncogenesis and confer resistance.

FUTURE DIRECTIONS

Thus, combinatorial approaches using ROS-generating agents alongside conventional therapeutics may prove an effective tactic to reduce NF-κB activity to kill cancer cells. One strategy is the use of thiosemicarbazones, which form redox-active metal complexes that generate high ROS levels to deliver potent antitumor activity. These agents also upregulate the metastasis suppressor, N-myc downstream regulated gene 1 (NDRG1), which functions as an NF-κB signaling inhibitor. It is proposed that targeting NF-κB signaling may proffer a new therapeutic niche to improve the efficacy of anticancer regimens.

Post-translational modifications in bladder cancer: Expanding the tumor target repertoire

Over the past decade, genomic and transcriptomic analyses have uncovered promising tumor antigens including immunotherapeutic targets in bladder cancer (BCa). Conventional tumor antigens are proteins expressed on the plasma membrane of tumor cells such as EGFR, FGFR3, and ERBB2 in BCa, which can be targeted by antibodies or similar epitope-specific binding reagents. The cellular proteome consists of ∼100,000 proteins but the expression of these proteins is rarely unique to tumor cells. Many tumor-associated proteins are post-translationally modified with phosphorylation, glycosylation, ubiquitination, or SUMOylation moieties. Although these modifications expand the complexity, they potentially offer novel targeting opportunities across tumor sub-populations. Experimental targeting of cancer-specific post-translational modifications (PTMs) has shown encouraging results in pre-clinical models of BCa, which could potentially overcome issues with inherent intra-tumor heterogeneity due to simultaneous expression on different proteins. Here, we review current knowledge on post-translational modifications in BCa and highlight recent efforts in experimental targeting strategies.

Loss of Fezf2 promotes malignant progression of bladder cancer by regulating the NF-κB signaling pathway

Forebrain embryonic zinc finger 2 (Fezf2) is an evolutionarily conserved zinc finger transcription repressor. It has been reported to be a tumor suppressor; however, neither the role that Fezf2 plays in bladder cancer nor the mechanisms involved have been investigated. In this study, we showed that Fezf2 expression is downregulated in bladder cancer tissues and cell lines compared to adjacent non-tumor tissues and normal urothelial cells. We also retrospectively analyzed the association between Fezf2 and various clinicopathologic characteristics in 196 bladder cancer patients, and showed that low expression of Fezf2 is correlated with larger tumor size, advanced tumor stage, and poor clinical prognosis. Moreover, we found that overexpression of Fezf2 significantly inhibited the proliferation, growth, migration, and invasion of bladder cancer cells, and attenuated angiogenesis, while knockdown of Fezf2 had the opposite effect. Fezf2 suppressed bladder cancer aggressiveness by activating the NF-κB signaling pathway. These findings suggest that Fezf2 holds promise as a prognostic biomarker, and provide a putative mechanism for bladder cancer progression.

Combination chemotherapy with Zyflamend reduced the acquired resistance of bladder cancer cells to cisplatin through inhibiting NFκB signaling pathway

Background

Cisplatin-based chemotherapy is mainstay treatment in urinary bladder cancer (UBC). However, tumor recurrence frequently occurs with the acquisition of cisplatin resistance. We explored the potential effect of a polyherbal preparation, Zyflamend, on UBC cells resistant to cisplatin treatment.

Methods

To establish a cisplatin-resistant human bladder cancer cell line, T24 cells were cultured in increasing concentrations of cisplatin for more than 10 months. These cells (T24R) were then treated with different concentrations of Zyflamend, and both proliferation and activity of nuclear factor kappaB (NFκB) signaling pathway were examined. To test the synergistic effect between Zyflamend and cisplatin, we treated T24R cells either with Zyflamend or cisplatin alone, or in combination. Apoptotic effect was evaluated by Annexin V/propidium iodide double staining, and the levels of the proteins involved in cell cycle and anti-apoptosis were examined by Western blotting. Finally, mice with palpable xenograft were treated either with cisplatin and Zyflamend alone or in combination for 28 days before they were sacrificed for measuring the sizes and weights of the tumor tissues. In addition, proliferation and apoptosis markers were examined by immunohistochemistry.

Results

Comparing to that in the parental T24 cells, NFκB is constitutively active in cisplatin-resistant T24R cells. Zyflamend is capable of inhibiting the growth of T24, T24R, as well as another UBC cell line J82 in a concentration-dependent manner. Mechanistically, Zyflamend suppresses NFκB-mediated cell proliferation, survival, and invasion/angiogenesis and induces apoptosis. In addition, Zyflamend significantly increased the sensitivity of T24R and J82 cells to cisplatin treatment and these findings were confirmed in T24R xenograft model with reduced proliferation index and decreased expression of RelA and its downstream target MMP9.

Conclusion

Zyflamend is capable of counteracting bladder cancer resistance to cisplatin by repressing proliferation and inducing apoptosis through targeting NFκB signaling pathway.

The Kraken Wakes: induced EMT as a driver of tumour aggression and poor outcome

Epithelial mesenchymal transition (EMT) describes the shift of cells from an epithelial form to a contact independent, migratory, mesenchymal form. In cancer the change is linked to invasion and metastasis. Tumour conditions, including hypoxia, acidosis and a range of treatments can trigger EMT, which is implicated in the subsequent development of resistance to those same treatments. Consequently, the degree to which EMT occurs may underpin the entire course of tumour progression and treatment response in a patient. In this review we look past the protective effect of EMT against the initial treatment, to the role of the mesenchymal state, once triggered, in promoting disease growth, spread and future treatment insensitivity. In patients a correlation was found between the propensity of a treatment to induce EMT and failure of that treatment to provide a survival benefit, implicating EMT induction in accelerated tumour progression after treatment cessation. Looking to the mechanisms driving this detrimental effect; increased proliferation, suppressed apoptosis, stem cell induction, augmented angiogenesis, enhanced metastatic dissemination, and immune tolerance, can all result from treatment-induced EMT and could worsen outcome. Evidence also suggests EMT induction with earlier therapies attenuates benefits of later treatments. Looking beyond epithelial tumours, de-differentiation also has therapy-attenuating effects and reversal thereof may yield similar rewards. A range of potential therapies are in development that may address the diverse mechanisms and molecular control systems involved in EMT-induced accelerated progression. Considering the broad reaching effects of mesenchymal shift identified, successful deployment of such treatments could substantially improve patient outcomes.

Synthetic artificial "long non-coding RNAs" targeting oncogenic microRNAs and transcriptional factors inhibit malignant phenotypes of bladder cancer cells

Both oncogenic transcription factors (TFs) and microRNAs (miRNAs) play important roles in human cancers, acting as transcriptional and post-transcriptional regulators, respectively. These phenomena raise questions about the ability of an artificial device to simultaneously regulate miRNAs and TFs. In this study, we aimed to construct artificial long non-coding RNAs, "alncRNAs", and to investigate their therapeutic effects on bladder cancer cell lines. Based on engineering principles of synthetic biology, we combined tandem arrayed aptamer cDNA sequences for TFs with tandem arrayed cDNA copies of binding sites for the miRNAs to construct alncRNAs. In order to prove the utility of this platform, we chose β-catenin and the miR-183-182-96 cluster as the functional targets and used the bladder cancer cell lines 5637 and SW780 as the test models. Dual-luciferase reporter assay, real-time quantitative PCR (qRT-PCR) and related phenotypic experiments were used to test the expression of related genes and the therapeutic effects of our devices. The result of dual-luciferase reporter assay and qRT-PCR showed that alncRNAs could inhibit transcriptional activity of TFs and expression of corresponding microRNAs. Using functional experiments, we observed decreased cell proliferation, increased apoptosis, and motility inhibition in alncRNA-infected bladder cancer cells. What's more, follow-up mechanism experiments further confirmed the anti-tumor effect of our devices. In summary, our synthetic devices indeed function as anti-tumor regulators, which synchronously accomplish transcriptional and post-transcriptional regulation in bladder cancer cells. Most importantly, anti-cancer effects were induced by the synthetic alncRNAs in the bladder cancer lines. Our devices, all in all, provided a novel strategy and methodology for cancer studies, and might show a great potential for cancer therapy if the challenges of in vivo DNA delivery are overcome.

Metformin increases the cytotoxicity of oxaliplatin in human DLD-1 colorectal cancer cells through down-regulating HMGB1 expression

Colorectal cancer (CRC) is the fourth most common cause of cancer death worldwide. Chemotherapy has been the major strategy for treating patients with advanced CRC. Oxaliplatin (OXA) is used as both an adjuvant and neoadjuvant anticancer agent available to treat advanced CRC. High-mobility group box 1 protein (HMGB1) is a critical regulator of cell death and survival. HMGB1 overexpression has been shown to be resistant to cytotoxic agents. In addition, Metformin, a widely used drug for diabetes, has emerged as a potential anticancer agent. In this study, we examined whether HMGB1 plays a role in the OXA- and/or metformin-induced cytotoxic effect on CRC cells. The results showed that treatment with OXA increased HMGB1 expression in the ERK1/2- and Akt-dependent manners in DLD-1 cells. HMGB1 gene knockdown enhanced the cytotoxicity and cell growth inhibition of OXA. Moreover, OXA-increased HMGB1 expression was by inducing NF-κB-DNA-binding activity to in DLD-1 cells. Compared to a single agent, OXA combined with metformin administration resulted in cytotoxicity and cell growth inhibition synergistically, accompanied with reduced HMGB1 level. These findings may have implications for the rational design of future drug regimens incorporating OXA and metformin for the treatment of CRC.

Ginkgolic acids induce HepG2 cell death via a combination of apoptosis, autophagy and the mitochondrial pathway

Ginkgolic acids may induce malignant cell death via the B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 apoptosis pathway. Concurrently, apoptosis, autophagy and mitochondrial dysfunction may also be involved in bringing about this endpoint. The anticancer effect of Ginkgolic acids (GAs) was investigated using the HepG2 cell line. The median lethal dose of the GAs of the HepG2 was measured via an MTT assay, the dose-response curves were evaluated and changes in cell morphology were monitored by microscopy. Autophagy in HepG2 cells was down regulated using 3-methyladenine (3-MA) or Beclin-1-specific small interfering RNA (siRNA) and the expression of apoptosis associated proteins caspase-3, Bax/Bcl-2, and the autophagy-associated protein 5 and microtubule-associated protein 1A/1B-light chain 3 in the GA-treated HepG2 cells were all measured by western blot analysis. The level of apoptosis in the GA-treated cells was also assessed using terminal deoxynucleotidyl-transferase-mediated dUTP nick-end labeling (TUNEL) assay, and the mitochondrial membrane potential (Δψ_m) was detected by immunofluorescence. The results of the MTT and TUNEL assays indicated that the proliferation of HepG2 cells treated with GAs was significantly reduced compared with the control group, and the rate of the inhibition was dose-dependent. Western blot analysis indicated that treatment with the Gas induced apoptosis and autophagy in the HepG2 cells. The Δψ_m of the GA-treated HepG2 cells was decreased compared with the control, as monitored by immunofluorescence. However, upon the administration of 3-MA or Beclin-1-specific siRNAs (inhibitors of the autophagy), the expression levels of the apoptosis- and autophagy-associated proteins were decreased. In conclusion, the results of the present study indicated that GAs are potent anticancer agents that function through a combination of the apoptosis, autophagy and mitochondrial pathways.

The molecular mechanisms of chemoresistance in cancers

Overcoming intrinsic and acquired drug resistance is a major challenge in treating cancer patients because chemoresistance causes recurrence, cancer dissemination and death. This review summarizes numerous molecular aspects of multi-resistance, including transporter pumps, oncogenes (EGFR, PI3K/Akt, Erk and NF-κB), tumor suppressor gene (p53), mitochondrial alteration, DNA repair, autophagy, epithelial-mesenchymal transition (EMT), cancer stemness, and exosome. The chemoresistance-related proteins are localized to extracellular ligand, membrane receptor, cytosolic signal messenger, and nuclear transcription factors for various events, including proliferation, apoptosis, EMT, autophagy and exosome. Their cross-talk frequently appears, such as the regulatory effects of EGFR-Akt-NF-κB signal pathway on the transcription of Bcl-2, Bcl-xL and survivin or EMT-related stemness. It is essential for the realization of the target, individualized and combine therapy to clarify these molecular mechanisms, explore the therapy target, screen chemosensitive population, and determine the efficacy of chemoreagents by cell culture and orthotopic model.

BST2 confers cisplatin resistance via NF-κB signaling in nasopharyngeal cancer

Concurrent/adjuvant cisplatin-based chemoradiotherapy is regarded as the standard of treatment for locoregionally advanced nasopharyngeal carcinoma (NPC). However, patients who do not respond to cisplatin suffer, rather than benefit, from chemotherapy treatment. The goal of this study was to identify molecules involved in cisplatin resistance and to clarify their molecular mechanisms, which would help in the discovery of potential therapeutic targets and in developing a personalized and precise treatment approach for NPC patients. We previously generated a cisplatin-sensitive NPC cell line, S16, from CNE2 cells and found that eIF3a, ASNS and MMP19 are upregulated in S16 cells, which contributes to their cisplatin sensitivity. In this study, we found that BST2 is downregulated in cisplatin-sensitive S16 cells compared with CNE2 cells. Knockdown of BST2 in NPC cells sensitized their response to cisplatin and promoted cisplatin-induced apoptosis, whereas exogenous overexpression of BST2 increased their cisplatin resistance and inhibited cisplatin-induced apoptosis. Further investigation demonstrated that BST2-mediated cisplatin resistance depended on the activation of the NF-κB signaling pathway and consequent upregulation of anti-apoptotic genes, such as Bcl-X_L and livin. Moreover, an analysis of clinical data revealed that a high BST2 level might serve as an independent indicator of poor prognosis in patients with locally advanced NPC treated with platinum-based chemoradiotherapy. These findings suggest that BST2 likely mediates platinum resistance in NPC, offering guidance for personalized and precise treatment strategies for patients with NPC.

TAZ overexpression is associated with epithelial-mesenchymal transition in cisplatin-resistant gastric cancer cells

Gastric cancer is one of the common malignant diseases. The poor treatment outcome is mainly due to chemotherapeutic resistance. Therefore, it is important to determine the molecular mechanism of drug resistance in gastric cancer. To explore the mechanisms of cisplatin resistance in gastric cancer cells, several approaches were performed including MTT assay, real-time RT-PCR, western blot analysis, migration and invasion assays, wound healing assay, and transfection. We found that cisplatin-resistant (CR) gastric cancer cells acquired epithelial-mesenchymal transition (EMT) phenotype. The CR cells with EMT features obtained higher migratory and invasive activities. Moreover, we observed that TAZ was highly expressed in CR cells. Consistently, depletion of TAZ caused partial reversal of EMT to MET in CR cells. Our results suggest that TAZ plays a pivotal role in CR-induced EMT. Targeting TAZ could be a potential therapeutic strategy for gastric cancer.

CYLD downregulates Livin and synergistically improves gemcitabine chemosensitivity and decreases migratory/invasive potential in bladder cancer: the effect is autophagy-associated

Although GC (gemcitabine and cisplatin) chemotherapy remains an effective method for treating bladder cancer (BCa), chemoresistance is a major obstacle in chemotherapy. In this study, we determined whether gemcitabine resistance correlates with migratory/invasive potential in BCa and whether this relationship is regulated by the cylindromatosis (CYLD)-Livin module. First, we independently investigated the correlation of CYLD/Livin and gemcitabine resistance with the potential for tumor migration and invasiveness. Second, we found that co-transfected CYLD and Livin dramatically improved sensitivity to gemcitabine chemotherapy and decreased migration/invasion potential. Next, we determined that CYLD may regulate Livin by the NF-κB-dependent pathway. We also found that CYLD overexpression and Livin knockdown might improve gemcitabine chemosensitivity by decreasing autophagy and increasing apoptosis in BCa cells. Finally, the effects of CYLD-Livin on tumor growth in vivo were evaluated. Our study demonstrates that CYLD-Livin might represent a potential therapeutic for chemoresistant BCa.