Correlation of Twist upregulation and senescence bypass during the progression and metastasis of cervical cancer

MiR-34b promotes oxidative stress and induces cellular senescence through TWIST1 in human cervical cancer

PURPOSE

The aim of this research was to elucidate the role of miR-34b in cervical cancer progression and the underlying mechanism behind the miR-34b-mediated tumor suppression. The study revealed the role of miR-34b as a senescence inducer and serves as a potential therapeutic target in developing combination therapy with senotherapeutics.

METHODS

MiR-34b was ectopically expressed in cervical cancer cell lines using a tetracycline inducible system and its effects on cell viability, apoptosis, senescence, DNA damage and oxidative stress were studied using MTT assay, acridine orange/ ethidium bromide staining, senescence associated β-galactosidase assay, gamma H2AX foci staining assay, western blotting and specific dyes for the detection of total and individual ROS species.

RESULTS

Ectopic expression of miR-34b promoted cellular senescence but no significant induction of apoptosis was observed in cervical cancer cell lines. MiR-34b promoted increase in oxidative stress through increase in total and individual ROS species and contributed to increase in cellular senescence. Mechanistically, miR-34b mediates its action by targeting TWIST1 as evidenced by the similar actions of TWIST1 shRNA in cervical cancer cell lines. Furthermore, our study revealed TWIST1 is one of the most significant targets of miR-34b targetome and identified RITA as a novel senolytic agent for use in combination therapy with miR-34b.

CONCLUSION

MiR-34b promotes cellular senescence and oxidative stress by targeting TWIST1, a known oncogene and EMT regulator. This study delved into the mechanism of miR-34b-mediated tumor suppression and provided novel insights for development of miR-34b based therapeutics for cervical cancer.

Cellular senescence and metabolic reprogramming: Unraveling the intricate crosstalk in the immunosuppressive tumor microenvironment

The intrinsic oncogenic mechanisms and properties of the tumor microenvironment (TME) have been extensively investigated. Primary features of the TME include metabolic reprogramming, hypoxia, chronic inflammation, and tumor immunosuppression. Previous studies suggest that senescence-associated secretory phenotypes that mediate intercellular information exchange play a role in the dynamic evolution of the TME. Specifically, hypoxic adaptation, metabolic dysregulation, and phenotypic shifts in immune cells regulated by cellular senescence synergistically contribute to the development of an immunosuppressive microenvironment and chronic inflammation, thereby promoting the progression of tumor events. This review provides a comprehensive summary of the processes by which cellular senescence regulates the dynamic evolution of the tumor-adapted TME, with focus on the complex mechanisms underlying the relationship between senescence and changes in the biological functions of tumor cells. The available findings suggest that components of the TME collectively contribute to the progression of tumor events. The potential applications and challenges of targeted cellular senescence-based and combination therapies in clinical settings are further discussed within the context of advancing cellular senescence-related research.

Clinicopathological and Prognostic Significance of CBX3 Expression in Human Cancer: a Systematic Review and Meta-analysis

BACKGROUND

Chromebox protein homolog 3 (CBX3) as a member of the heterochromatin-associated protein 1 (HP1) family has been reported to be overexpressed in human cancer tissues. Numerous studies have shown the relationship between the CBX3 expression and clinicopathological factor or prognosis in malignant tumors, but their results are inconsistent. To address these results, a meta-analysis was described to investigate the prognostic value and clinicopathological significance of CBX3 expression in human malignant neoplasms.

METHODS

PubMed, Web of Science, Embase, and Chinese National Knowledge Infrastructure (CNKI) were used to search eligible literatures, including publications prior to September 2019. The role of CBX3 in cancer prognosis and clinicopathological characteristics was assessed by pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Eleven studies with 1682 cancer patients were enrolled in this meta-analysis. This analysis demonstrated that the patients' increased CBX3 expression was significantly associated with poor overall survival (OS) (univariate analysis: HR = 1.81, 95% CI 1.46-2.25; multivariate analysis: HR = 1.95, 95% CI 1.63-2.34). Subgroups analysis by tumor type also indicated that high expression of CBX3 was correlated with poor OS in tongue squamous cell carcinoma (HR = 3.31, 95% CI 2.03-5.39), lung cancer (HR = 1.66, 95% CI 1.21-2.29), genitourinary cancer (HR = 2.03, 95% CI 1.15-3.58), and digestive cancer (HR = 1.48, 95% CI 1.23-1.79). For clinicopathological features, high expression of CBX3 was associated with lymph node metastasis (OR = 2.96, 95% CI 1.42-6.20) and lager tumor size (OR = 1.60, 95% CI 1.12-2.28).

CONCLUSION

The results of this meta-analysis indicated that CBX3 expression may be a novel biomarker for predicting patient prognosis and clinicopathological parameters in multiple human cancer.

Exposure to TNF‑α combined with TGF‑β induces carcinogenesis in vitro via NF-κB/Twist axis

Persistent human papilloma virus (HPV) infection induces chronic inflammation resulting in human cervical cancer. However, the mechanisms underlying carcinogenesis via chronic inflammation remain largely unclear. We investigated the role of pro-inflammatory factors in epithelial-mesenchymal transition (EMT) and cancer stem cell-like (CSCL) characteristics of HeLa cells exposed to TNF‑α with or without TGF‑β. We then determined the role of NF-κB/Twist signal axis in the pathogenesis of cervical cancer. We found that HeLa cells exposed to TNF‑α following chronic treatment with TGF‑β exhibited EMT, self-renewal and high mobility. Knockdown of NF-κBp65 inhibited NF-κB and Twist1 expression, and EMT and CSCL properties of HeLa cells following co-treatment with TNF‑α and TGF‑β. Conversely, overexpression of NF-κBp65 potentiated the above effects. However, knockdown or overexpression of Twist1 had no effect on NF-κBp65 expression, but inhibited or promoted EMT and CSCL features. Notably, overexpression of Twist1 rescued NF-κBp65 knockdown. Our results demonstrate the role of NF-κB/Twist signaling axis in which HeLa cells treated with TNF‑α following chronic exposure to TGF‑β induce EMT and CSCL properties. The NF-κB/Twist signal axis may represent an effective therapeutic target in cervical cancer.

Role of epithelial to mesenchymal transition proteins in gynecological cancers: pathological and therapeutic perspectives

Gynecorelogic cancers like ovarian, cervical, and endometrial cancers are among the major threats to modern life, especially to female health. Like some other types of cancers, all of these gynecological cancers have found to be associated with the developmental stage epithelial to mesenchymal transition (EMT). More specifically, the aberrant expression of major EMT markers, such as lower expressions of E-cadherin and alpha-catenin, and overexpressions of N-cadherin, beta-catenin, vimentin, and matrix metalloproteinases, have been reported in ovarian, cervical, and endometrial cancers. The transcription factors, such as Twist, Snail, Slug, and Zeb, which regulate these EMT mediators, are also reported to be overexpressed in gynecological cancers. In addition to the over/lower expression, the promoter methylation of some of these genes has been identified too. In the era of target-specific cancer therapeutics, some promising studies showed that targeting EMT markers might be an interesting and successful tool in future cancer therapy. In this study, we have reviewed the recent development in the research on the association of EMT markers with three major gynecological cancers in the perspectives of carcinogenesis and therapeutics.