The Phytochemical α-Mangostin Inhibits Cervical Cancer Cell Proliferation and Tumor Growth by Downregulating E6/E7-HPV Oncogenes and KCNH1 Gene Expression.

Cervical cancer is the fourth most common cancer among women worldwide. The main factor associated with the onset and progression of this neoplasia is the human papillomavirus (HPV) infection. The HPV-oncogenes E6 and E7 are critical drivers of cellular transformation, promoting the expression of oncogenes such as KCNH1. The phytochemical α-mangostin (AM) is a potent antineoplastic and antiviral compound. However, its effects on HPV oncogenes and KCNH1 gene expression remain unknown. This study evaluated the effects of AM on cell proliferation, cell cycle distribution and gene expression, including its effects on tumor growth in xenografted mice. AM inhibited cell proliferation in a concentration-dependent manner, being the most sensitive cell lines those with the highest number of HPV16 copies. In addition, AM promoted G1-cell cycle arrest in CaSki cells, while led to cell death in SiHa and HeLa cells. Of interest was the finding of an AM-dependent decreased gene expression of E6, E7 and KCNH1 both in vitro and in vivo, as well as the modulation of cytokine expression, Ki-67, and tumor growth inhibition. On these bases, we suggest that AM represents a good option as an adjuvant for the treatment and prevention of cervical cancer.

Emodin Sensitizes Cervical Cancer Cells to Vinblastine by Inducing Apoptosis and Mitotic Death.

In recent years, studies on the effects of combining novel plant compounds with cytostatics used in cancer therapy have received considerable attention. Since emodin sensitizes tumor cells to chemotherapeutics, we evaluated changes in cervical cancer cells after its combination with the antimitotic drug vinblastine. Cellular changes were demonstrated using optical, fluorescence, confocal and electron microscopy. Cell viability was assessed by MTT assay. The level of apoptosis, caspase 3/7, Bcl-2 protein, ROS, mitochondrial membrane depolarization, cell cycle and degree of DNA damage were analyzed by flow cytometry. The microscopic image showed indicators characteristic for emodin- and vinblastine-induced mitotic catastrophe, i.e., multinucleated cells, giant cells, cells with micronuclei, and abnormal mitotic figures. These compounds also increased blocking of cells in the G2/M phase, and the generated ROS induced swelling and mitochondrial damage. This translated into the growth of apoptotic cells with active caspase 3/7 and inactivation of Bcl-2 protein and active ATM kinase. Emodin potentiated the cytotoxic effect of vinblastine, increasing oxidative stress, mitotic catastrophe and apoptosis. Preliminary studies show that the combined action of both compounds, may constitute an interesting form of anticancer therapy.

The Multidirectional Effect of Azelastine Hydrochloride on Cervical Cancer Cells.

A major cause of cancer cell resistance to chemotherapeutics is the blocking of apoptosis and induction of autophagy in the context of cell adaptation and survival. Therefore, new compounds are being sought, also among drugs that are commonly used in other therapies. Due to the involvement of histamine in the regulation of processes occurring during the development of many types of cancer, antihistamines are now receiving special attention. Our study concerned the identification of new mechanisms of action of azelastine hydrochloride, used in antiallergic treatment. The study was performed on HeLa cells treated with different concentrations of azelastine (15-90 µM). Cell cycle, level of autophagy (LC3 protein activity) and apoptosis (annexin V assay), activity of caspase 3/7, anti-apoptotic protein of Bcl-2 family, ROS concentration, measurement of mitochondrial membrane potential (Δψm), and level of phosphorylated H2A.X in response to DSB were evaluated by cytometric method. Cellular changes were also demonstrated at the level of transmission electron microscopy and optical and fluorescence microscopy. Lysosomal enzyme activities-cathepsin D and L and cell viability (MTT assay) were assessed spectrophotometrically. Results: Azelastine in concentrations of 15-25 µM induced degradation processes, vacuolization, increase in cathepsin D and L activity, and LC3 protein activation. By increasing ROS, it also caused DNA damage and blocked cells in the S phase of the cell cycle. At the concentrations of 45-90 µM, azelastine clearly promoted apoptosis by activation of caspase 3/7 and inactivation of Bcl-2 protein. Fragmentation of cell nucleus was confirmed by DAPI staining. Changes were also found in the endoplasmic reticulum and mitochondria, whose damage was confirmed by staining with rhodamine 123 and in the MTT test. Azelastine decreased the mitotic index and induced mitotic catastrophe. Studies demonstrated the multidirectional effects of azelastine on HeLa cells, including anti-proliferative, cytotoxic, autophagic, and apoptotic properties, which were the predominant mechanism of death. The revealed novel properties of azelastine may be practically used in anti-cancer therapy in the future.

A New Perspective on Cancer Therapy: Changing the Treaded Path?

During the last decade, we have persistently addressed the question, "how can the innate immune system be used as a therapeutic tool to eliminate cancer?" A cancerous tumor harbors innate immune cells such as macrophages, which are held in the tumor-promoting M2 state by tumor-cell-released cytokines. We have discovered that these tumor-associated macrophages (TAM) are repolarized into the nitric oxide (NO)-generating tumoricidal M1 state by the dietary agent curcumin (CC), which also causes recruitment of activated natural killer (NK) cells and cytotoxic T (Tc) cells into the tumor, thereby eliminating cancer cells as well as cancer stem cells. Indications are that this process may be NO-dependent. Intriguingly, the maximum blood concentration of CC in mice never exceeds nanomolar levels. Thus, our results submit that even low, transient levels of curcumin in vivo are enough to cause repolarization of the TAM and recruitment NK cells as well as Tc cells to eliminate the tumor. We have observed this phenomenon in two cancer models, glioblastoma and cervical cancer. Therefore, this approach may yield a general strategy to fight cancer. Our mechanistic studies have so far implicated induction of STAT-1 in this M2→M1 switch, but further studies are needed to understand the involvement of other factors such as the lipid metabolites resolvins in the CC-evoked anticancer pathways.

Adjuvant Human Papillomavirus Vaccine to Reduce Recurrent Cervical Dysplasia in Unvaccinated Women: A Systematic Review and Meta-analysis.

OBJECTIVE: To perform a systematic review and meta-analysis evaluating the efficacy of adjuvant human papillomavirus (HPV) vaccination in preventing recurrent cervical intraepithelial neoplasia (CIN) 2 or greater after surgical excision. DATA SOURCES: Electronic databases (Cochrane, PubMed, EMBASE, MEDLINE, Scopus, and ClinicalTrials.gov) were searched for studies comparing surgical excision alone to surgical excision with adjuvant HPV vaccination for CIN 2 or greater. Studies published from January 1990 to January 2019 were included. METHODS: A total of 5,901 studies were reviewed. The primary outcomes evaluated included: recurrence of CIN 2 or greater, CIN 1 or greater, and HPV 16,18 associated CIN within 6-48 months. We used Covidence software to assist with screening, and meta-analysis was performed using Review Manager. TABULATION, INTEGRATION, AND RESULTS: Six studies met inclusion criteria and were included in the final analysis. In total 2,984 women were included; 1,360 (45.6%) received adjuvant HPV vaccination after surgical excision, and 1,624 (54.4%) received either placebo or surgical management alone for CIN 2 or greater. Recurrence of CIN 2 or greater occurred within 6-48 months in 115 women (3.9%) overall; however, recurrence was significantly lower for vaccinated women: 26 of 1,360 women (1.9%) vs 89 of 1,624 unvaccinated women (5.9%) (relative risk [RR] 0.36 95% CI 0.23-0.55). The risk of CIN 1 or greater was also significantly lower with adjuvant HPV vaccination, occurring in 86 of 1,360 vaccinated women (6.3%) vs 157 of 1,624 unvaccinated women (9.7%) (RR 0.67 95% CI 0.52-0.85). Thirty-five women developed recurrent CIN 2 or greater lesions specific to HPV 16,18; nine received adjuvant vaccination (0.9%) vs 26 who were unvaccinated (2.0%) (RR 0.41 95% CI 0.20-0.85). CONCLUSION: Adjuvant HPV vaccination in the setting of surgical excision for CIN 2 or greater is associated with a reduced risk of recurrent cervical dysplasia overall and a reduction in the risk of recurrent lesions caused by the most oncogenic strains (HPV 16,18). Human papillomavirus vaccination should therefore be considered for adjuvant treatment in patients undergoing surgical excision for CIN 2 or greater. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42019123786.