MicroRNA-29a Manifests Multifaceted Features to Intensify Radiosensitivity, Escalate Apoptosis, and Revoke Cell Migration for Palliating Radioresistance-Enhanced Cervical Cancer Progression

Combined Effects of Annexin A5 Overexpression, 5-Fluorouracil Treatment, and Irradiation on Cell Viability of Caski Cervical Cancer Cell Line

Cervical cancer is the fourth leading cause of cancer deaths in women globally. Combining gene therapy with chemo- and radiotherapy may improve cervical cancer treatment outcomes. This study evaluated the effects of Annexin A5(ANXA5) overexpression alongside 5-fluorouracil (5-FU) and irradiation on the viability of CaSki cervical squamous cell carcinoma (SCC) cells. pAdenoVator-CMV-ANXA5-IRES-GFP-plasmid and mock plasmid were transfected into CaSki cells using calcium-phosphate. Seventy-two hours post-transfection, GFP expression was quantified by fluorescence microscopy and flow cytometry to evaluate transfection efficiency. ANXA5 overexpression was confirmed via qPCR. Twenty-four hours post-transfection, cells received a single dose of 8 Gy and were treated with 1 and 2 µg/ml of 5-FU (IC50 = 2.783 µg/ml). Cell viability, apoptosis, cell cycle stage, and Bcl-2 and Bax gene expression were assessed via MTT, annexin V/7-AAD, PI staining, and qPCR assays, respectively. ANXA5 was overexpressed 31.5-fold compared to control (p < 0.0001). MTT assays showed ANXA5 overexpression dose-dependently reduced CaSki cell viability (p < 0.001). IC50 of 5-FU was reduced from 2.783 μg/mL to 1.794 μg/mL when combined with ANXA5 overexpression. Additive effects on cell death were observed for ANXA5 plus 5-FU or irradiation versus ANXA5 alone. Apoptosis assays indicated combinatorial treatment increased CaSki cell apoptosis over ANXA5 alone. Cell cycle analysis revealed ANXA5 arrested cell cycle at G1/S phases; the percentage of cells in the S phase further rose with combination treatment. Finally, combination therapy significantly decreased Bcl-2 expression and increased Bax versus control (p < 0.001). Altogether, ANXA5 overexpression alongside 5-FU and irradiation may improve cervical squamous cell carcinoma (SCC) treatment efficacy. Further, in vivo investigations are warranted to confirm these in vitro results.

The research progress on radiation resistance of cervical cancer

Cervical carcinoma is the most prevalent gynecology malignant tumor and ranks as the fourth most common cancer worldwide, thus posing a significant threat to the lives and health of women. Advanced and early-stage cervical carcinoma patients with high-risk factors require adjuvant treatment following surgery, with radiotherapy being the primary approach. However, the tolerance of cervical cancer to radiotherapy has become a major obstacle in its treatment. Recent studies have demonstrated that radiation resistance in cervical cancer is closely associated with DNA damage repair pathways, the tumor microenvironment, tumor stem cells, hypoxia, cell cycle arrest, and epigenetic mechanisms, among other factors. The development of tumor radiation resistance involves complex interactions between multiple genes, pathways, and mechanisms, wherein each factor interacts through one or more signaling pathways. This paper provides an overview of research progress on an understanding of the mechanism underlying radiation resistance in cervical cancer.

Aldolase A promotes cervical cancer cell radioresistance by regulating the glycolysis and DNA damage after irradiation

Radioresistance is the major obstacle that affects the efficacy of radiotherapy which is an important treatment for cervical cancer. By analyzing the databases, we found that aldolase A (ALDOA), which is a key enzyme in metabolic reprogramming, has a higher expression in cervical cancer patients and is associated with poor prognosis. We detected the expression of ALDOA in the constructed cervical cancer radioresistance (RR) cells by repetitive irradiation and found that it was upregulated compared to the control cells. Functional assays were conducted and the results showed that the knockdown of ALDOA in cervical cancer RR cells inhibited the proliferation, migration, and clonogenic abilities by regulating the cell glycolysis. In addition, downregulation of ALDOA enhanced radiation-induced apoptosis and DNA damage by causing G2/M phase arrest and further promoted radiosensitivity of cervical cancer cells. The functions of ALDOA in regulating tumor radiosensitivity were also verified by the mouse tumor transplantation model in vivo. Therefore, our study provides new insights into the functions of ALDOA in regulating the efficacy of radiotherapy and indicates that ALDOA might be a promising target for enhancing radiosensitivity in treating cervical cancer patients.

A novel nomogram and risk stratification for early metastasis in cervical cancer after radical radiotherapy

OBJECT

This study aimed to establish an effective risk nomogram to predict the early distant metastasis (EDM) probability of cervical cancer (CC) patients treated with radical radiotherapy to aid individualized clinical decision-making.

METHODS

A total of 489 patients with biopsy-confirmed CC between December 2018 and January 2021 were enrolled. Logistic regression with the stepwise backward method was used to identify independent risk factors. The nomogram efficacy was evaluated by using the area under the receiver operating characteristic curve (AUC), C-index by 1000 bootstrap replications, etc. Finally, patients were divided into high- and low-risk groups of EDM based on the cut-off value of nomogram points.

RESULTS

36 (7.36%) CC patients had EDM, and 20 (55.6%) EDM had more than one metastatic site involved. Age below 51 (OR = 2.298, p < 0.001), tumor size larger than 4.5 cm (OR = 3.817, p < 0.001) and radiotherapy (OR = 3.319, p < 0.001) were independent risk factors of EDM. For the nomogram model, C-index was 0.701 (95% CI = 0.604-0.798), and 0.675 (95% CI = 0.578-0.760) after 1000 bootstrap resampling validations. The Hosmer-Lemeshow test demonstrated no overfitting (p = 0.924). According to the Kaplan-Meier curve of risk score, patients with high risk were more prone to get EDM (p < 0.001).

CONCLUSION

This is the first research to focus on EDM in CC patients. We have developed a robust scoring system to predict the risk of EDM in CC patients to screen out appropriate cases for consolidation therapy and more intensive follow-up.

Review of possible mechanisms of radiotherapy resistance in cervical cancer

Radiotherapy is one of the main treatments for cervical cancer. Early cervical cancer is usually considered postoperative radiotherapy alone. Radiotherapy combined with cisplatin is the standard treatment for locally advanced cervical cancer (LACC), but sometimes the disease will relapse within a short time after the end of treatment. Tumor recurrence is usually related to the inherent radiation resistance of the tumor, mainly involving cell proliferation, apoptosis, DNA repair, tumor microenvironment, tumor metabolism, and stem cells. In the past few decades, the mechanism of radiotherapy resistance of cervical cancer has been extensively studied, but due to its complex process, the specific mechanism of radiotherapy resistance of cervical cancer is still not fully understood. In this review, we discuss the current status of radiotherapy resistance in cervical cancer and the possible mechanisms of radiotherapy resistance, and provide favorable therapeutic targets for improving radiotherapy sensitivity. In conclusion, this article describes the importance of understanding the pathway and target of radioresistance for cervical cancer to promote the development of effective radiotherapy sensitizers.

NOVAprep-miR-Cervix: New Method for Evaluation of Cervical Dysplasia Severity Based on Analysis of Six miRNAs

Cervical cancer is one of the most common gynecological malignancies and it is preventable through the yearly diagnosis and management of pre-cancerous cervical disease. The profile of miRNA expression in cervical epithelium cells is altered with cervical dysplasia development and further progression. The NOVAprep-miR-CERVIX is a new approach for the assessment of cervical dysplasia through the analysis of six marker miRNAs. This study aims to evaluate theperformance and diagnostic potency of the new method. Cytological smears from 226 women (NILM, n.114; HSIL, n.112) were included in the study. A VPH test was performed with RealBest DNAHPV HR screen Kit, six marker miRNAs (miR-21, -29b, -145, -451a, -1246, -1290) were assayed using NOVAprep-miR-CERVIX kit. Obtained data were analyzed using the Delta Ct method and random forest machine learning algorithm. The results of the quantitative analysis of six microRNAs were expressed as a miR-CERVIX parameter, which ranged from 0 to 1, where "0" corresponded to the healthy cervical epithelium, while "1" corresponded to high-grade squamous intraepithelial dysplasia. The average value of miR-CERVIX differed in groups of NILM and HSIL samples (0.34 vs. 0.72; p < 0.000005). An estimation of miR-CERVIX allowed for the differentiation between healthy and pre-cancerous samples with sensitivity of 0.79 and specificity of 0.79, as well as to confirm HSIL with specificity of 0.98. Interestingly, the HSIL group included HPV(+) and HPV(-) samples, which were statistically significantly different in terms of miR-CERVIX value. Analysis of CC-associated miRNAs in material of cervical smear might serve as an additional method for the evaluation of cervical dysplasia severity.

Improving the prediction for the response to radiotherapy of clinical tumor samples by using combinatorial model of MicroRNA expression

Purpose: Radiation therapy (RT) is one of the main treatments for cancer. The response to radiotherapy varies widely between individuals and some patients have poor response to RT treatment due to tumor radioresistance. Stratifying patients according to molecular signatures of individual tumor characteristics can improve clinical treatment. In here, we aimed to use clinical and genomic databases to develop miRNA signatures that can predict response to radiotherapy in various cancer types.

Methods: We analyzed the miRNAs profiles using tumor samples treated with RT across eight types of human cancers from TCGA database. These samples were divided into response group (S, n = 224) and progressive disease group (R, n = 134) based on RT response of tumors. To enhance the discrimination for S and R samples, the predictive models based on binary logistic regression were developed to identify the best combinations of multiple miRNAs.

Results: The miRNAs differentially expressed between the groups S and R in each caner type were identified. Total 47 miRNAs were identified in eight cancer types (p values &lt;0.05, t-test), including several miRNAs previously reported to be associated with radiotherapy sensitivity. Functional enrichment analysis revealed that epithelial-to-mesenchymal transition (EMT), stem cell, NF-κB signal, immune response, cell death, cell cycle, and DNA damage response and DNA damage repair processes were significantly enriched. The cancer-type-specific miRNA signatures were identified, which consist of 2-13 of miRNAs in each caner type. Receiver operating characteristic (ROC) analyses showed that the most of individual miRNAs were effective in distinguishing responsive and non-responsive patients (the area under the curve (AUC) ranging from 0.606 to 0.889). The patient stratification was further improved by applying the combinatorial model of miRNA expression (AUC ranging from 0.711 to 0.992). Also, five miRNAs that were significantly associated with overall survival were identified as prognostic miRNAs.

Conclusion: These mRNA signatures could be used as potential biomarkers selecting patients who will benefit from radiotherapy. Our study identified a series of miRNA that were differentially expressed between RT good responders and poor responders, providing useful clues for further functional assays to demonstrate a possible regulatory role in radioresistance.