Breaking down the evidence for bevacizumab in advanced cervical cancer: past, present and future

Novel Antigenic Targets of HPV Therapeutic Vaccines

Human papillomavirus (HPV) infection is the cause of the majority of cervical cancers and head and neck cancers worldwide. Although prophylactic vaccines and cervical cancer screening programs have shown efficacy in preventing HPV-associated cervical cancer, cervical cancer is still a major cause of morbidity and mortality, especially in third world countries. Furthermore, head and neck cancer cases caused by HPV infection and associated mortality are increasing. The need for better therapy is clear, and therapeutic vaccination generating cytotoxic T cells against HPV proteins is a promising strategy. This review covers the current scene of HPV therapeutic vaccines in clinical development and discusses relevant considerations for the design of future HPV therapeutic vaccines and clinical trials, such as HPV protein expression patterns, immunogenicity, and exhaustion in relation to the different stages and types of HPV-associated lesions and cancers. Ultimately, while the majority of the HPV therapeutic vaccines currently in clinical testing target the two HPV oncoproteins E6 and E7, we suggest that there is a need to include more HPV antigens in future HPV therapeutic vaccines to increase efficacy and find that especially E1 and E2 could be promising novel targets.

LncRNA AFAP1-AS1/miR-27b-3p/VEGF-C axis modulates stemness characteristics in cervical cancer cells

Background:

Long non-coding RNA (lncRNA) actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) functions as a competing endogenous RNA to regulate target genes expression by sponging microRNAs (miRs) to play cancer-promoting roles in cancer stem cells. However, the regulatory mechanism of AFAP1-AS1 in cervical cancer (CC) stem cells is unknown. The present study aimed to provide a new therapeutic target for the clinical treatment of CC.

Methods:

Hyaluronic acid receptor cluster of differentiation 44 variant exon 6 (CD44v6)(+) CC cells were isolated by flow cytometry (FCM). Small interfering RNAs of AFAP1-AS1 (siAFAP1-AS1) were transfected into the (CD44v6)(+) cells. The levels of AFAP1-AS1 were measured by quantitative real-time PCR (qRT-PCR). Sphere formation assay, cell cycle analysis, and Western blotting were used to detect the effect of siAFAP1-AS1. RNA pull-down and luciferase reporter assay were used to verify the relationship between miR-27b-3p and AFAP1-AS1 or vascular endothelial growth factor (VEGF)-C.

Results:

CD44v6(+) CC cells had remarkable stemness and a high level of AFAP1-AS1. However, AFAP1-AS1 knockdown with siAFAP1-AS1 suppressed the cell cycle transition of G(1)/S phase and inhibited self-renewal of CD44v6(+) CC cells, the levels of the stemness markers octamer-binding transcription factor 4 (OCT4), osteopontin (OPN), and cluster of differentiation 133 (CD133), and the epithelial-mesenchymal transition (EMT)-related proteins Twist1, matrix metalloprotease (MMP)-9, and VEGF-C. In the mechanism study, miR-27b-3p/VEGF-C signaling was demonstrated to be a key downstream of AFAP1-AS1 in the CD44v6(+) CC cells.

Conclusions:

LncRNA AFAP1-AS1 knockdown inhibits the CC cell stemness by upregulating miR-27b-3p to suppress VEGF-C.

The Incorporation of Immunotherapy and Targeted Therapy Into Chemoradiation for Cervical Cancer: A Focused Review

In 2011 the Food and Drug Administration (FDA) approved anti-vascular endothelial growth factor (VEGF) therapy, bevacizumab, for intractable melanoma. Within the year, immunotherapy modulators inhibiting cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) were approved in addition to programmed death-ligand 1 (PD-L1) antibodies in 2012. Since then, research showing the effectiveness of targeted therapies in a wide range of solid tumors has prompted studies incorporating their inclusion as part of upfront management as well as refractory or relapsed disease. For treatment of cervical cancer, which arises from known virus-driven oncogenic pathways, the incorporation of targeted therapy is a particularly attractive prospect. The current standard of care for locally advanced cervical cancer includes concurrent platinum-based chemotherapy with radiation therapy (CRT) including external beam radiation therapy (EBRT) and brachytherapy. Building upon encouraging results from trials testing bevacizumab or immunotherapy in recurrent cervical cancer, these agents have begun to be incorporated into upfront CRT strategies for prospective study. This article will review background data establishing efficacy of angiogenesis inhibitors and immunotherapy in the treatment of cervical cancer as well as results of prospective studies combining targeted therapies with standard CRT with the aim of improving outcomes. In addition, the role of immunotherapy and radiation on the tumor microenvironment (TME) will be discussed.

The Role of Predictive Biomarkers in Endocervical Adenocarcinoma: Recommendations From the International Society of Gynecological Pathologists

To review the scientific evidence related to predictive biomarkers in cervical adenocarcinoma (ADC). The authors reviewed the literature regarding predictive biomarkers in cervical ADC. There were several limitations: (1) there is an overlap between predictive and prognostic biomarkers, as the vast majority of patients are treated with anticancer strategies; (2) in many studies and clinical trials, cervical ADC patients are included in a large series of patients predominantly composed of cervical squamous cell carcinomas; and (3) in most of the studies, and clinical trials, there is no distinction between human papillomavirus (HPV)-associated and HPV-independent cervical ADCs, or between various histologic subtypes. Results obtained from a small group of studies confirm that cervical ADCs exhibit distinct molecular features as compared with squamous carcinomas, and that there are different molecular features between different types of cervical ADCs. Promising areas of interest include ERBB2 (HER2) mutations and PD-L1 expression as predictive biomarkers for anti-HER2 treatment and immunotherapy, respectively. To date, no definitive data can be obtained from the literature regarding predictive biomarkers for cervical ADC. Clinical trials specifically designed for endocervical ADC patients are required to elucidate the predictive value of HER2 mutations and PD-L1 expression. The distinction between HPV-associated and HPV-independent cervical ADCs as well as early involvement of pathologists in the design of future clinical trials are needed to identify new predictive biomarkers in cervical ADC.

NMK-BH2, a novel microtubule-depolymerising bis (indolyl)-hydrazide-hydrazone, induces apoptotic and autophagic cell death in cervical cancer cells by binding to tubulin at colchicine - site

BACKGROUND

Microtubules, the key components of the eukaryotic cytoskeleton and mitotic spindle, are one of the most sought-after targets for cancer chemotherapy, especially due to their indispensible role in mitosis. Cervical cancer is a prevalent malignancy among women of developing countries including India. In spite of the remarkable therapeutic advancement, the non-specificity of chemotherapeutic drugs adversely affect the patients' survival and well-being, thus, necessitating the quest for novel indole-based anti-microtubule agent against cervical cancer, with high degree of potency and selectivity.

METHODS

For in vitro studies, we used MTT assay, confocal microscopy, fluorescence microscopy, flow cytometry and Western blot analysis. Study in cell free system was accomplished by spectrophotometry, fluorescence spectroscopy and TEM and computational analysis was done by AutodockTools 1.5.6.

RESULTS

NMK-BH2 exhibited significant and selective anti-proliferative activity against cervical cancer HeLa cells (IC₅₀ = 1.5 μM) over normal cells. It perturbed the cytoskeletal and spindle microtubules of HeLa cells leading to mitotic block and cell death by apoptosis and autophagy. Furthermore, NMK-BH2 targeted the tubulin-microtubule system through fast and strong binding to the αβ-tubulin heterodimers at colchicine-site.

CONCLUSION

This study identifies and characterises NMK-BH2 as a novel anti-microtubule agent and provides insights into its key anti-cancer mechanism through two different cell death pathways: apoptosis and autophagy, which are mutually independent.

GENERAL SIGNIFICANCE

It navigates the potential of the novel bis (indolyl)-hydrazide-hydrazone, NMK-BH2, to serve as lead for development of new generation microtubule-disrupting chemotherapeutic with improved efficacy and remarkable selectivity towards better cure of cervical cancer.

A new marker based on risk stratification of human papillomavirus DNA and tumor size to predict survival of locally advanced cervical cancer

OBJECTIVE

To assess the prognostic value of human papillomavirus (HPV) viral load in locally advanced cervical carcinoma treated with radical concurrent chemoradiotherapy.

METHODS

From January 2012 to October 2013, a total of 246 locally advanced cervical carcinoma patients were included in this retrospective study. HPV DNA status was tested by Hybrid Capture 2 assay. Tumor size was measured on T2WI. All the patients in the study received concurrent cisplatin-based chemoradiotherapy with intensity-modulated radiotherapy and three-dimensional brachytherapy. Survival rate was calculated by the Kaplan-Meier method, and a log-rank test was used to compare the survival. Multivariate analysis employed the Cox regression model.

RESULTS

The median follow-up time was 52 months. The median value of HPV DNA was 163.13 relative light unit/cut-off (RLU/CO) (range 1.65-2162.62 RLU/CO). The 5-year overall survival, distant metastasis-free survival of patients in the low HPV DNA group (HPV DNA ≤ 163.13 RLU/CO) and the high HPV DNA group (HPV DNA > 163.13 RLU/CO) were 46.3 % vs 58.5 % (p = 0.009) and 65.9 % vs 75.6% (p = 0.003), respectively. Multivariate analysis showed that the HPV DNA, tumor size, and International Federation of Gynecology and Obstetrics (FIGO) stage were independent prognostic factors for overall survival and distant metastasis-free survival. We choose the tumor size and HPV DNA as the risk stratification factors to build a new prediction marker which can better predict overall survival for locally advanced cervical cancer than can the FIGO stage.

CONCLUSIONS

HPV DNA may be a useful biomarker for locally advanced cervical cancer. Low HPV load predicts a worse survival. The new marker based on risk stratification by combining HPV DNA and tumor size is better associated with overall survival of locally advanced cervical cancer treated with concurrent chemoradiotherapy.

Cervical cancer - State of the science: From angiogenesis blockade to checkpoint inhibition

Vascular endothelial growth factor (VEGF) has emerged as a therapeutic target in several malignancies, including cervical cancer. Chemotherapy doublets combined with the fully humanized monoclonal antibody, bevacizumab, now constitute first-line therapy for women struggling with recurrent/metastatic cervical carcinoma. Regulatory approval for this indication was based on the phase III randomized trial, GOG 240, which demonstrated a statistically significant and clinically meaningful improvement in overall survival when bevacizumab was added to chemotherapy: 17.0 vs 13.3 months; HR 0.71; 98% CI, 0.54-0.95; p = .004. Incorporation of bevacizumab resulted in significant improvements in progression-free survival and response. These benefits were not accompanied by deterioration in quality of life. GOG 240 identified vaginal fistula as a new adverse event associated with bevacizumab use. All fistulas occurred in women who had received prior pelvic radiotherapy, and none resulted in emergency surgery, sepsis, or death. Final protocol-specified analysis demonstrated continued separation of the survival curves favoring VEGF inhibition: 16.8 vs 13.3 months; HR 0.77; 95% CI, 0.62-9.95; p = .007. Post-progression survival was not significantly different between the arms in GOG 240. Moving forward, immunotherapy has now entered the clinical trial arena to address the high unmet clinical need for effective and tolerable second line therapies in this patient population. Targeting the programmed cell death 1/programmed death ligand 1 (PD-1/PD-L1) pathway using checkpoint inhibitors to break immunologic tolerance is promising. The immunologic landscape involving human papillomavirus-positive head and neck carcinoma and cutaneous squamous cell carcinoma can be informative when considering feasibility of checkpoint blockade in advanced cervical cancer. Phase II studies using anti-PD-1 molecules, nivolumab and pembrolizumab are ongoing, and GOG 3016, the first phase III randomized trial of a checkpoint inhibitor (cemiplimab) in cervical cancer, recently activated. Important considerations in attempts to inhibit the inhibitors include pseudoprogression and post-progression survival, abscopal effects, and immune-related adverse events, including endocrinopathies.