Berberine modulates AP-1 activity to suppress HPV transcription and downstream signaling to induce growth arrest and apoptosis in cervical cancer cells

<p>Abstract</p> <p>Background-</p> <p>Specific types of high risk Human papillomaviruses (HR-HPVs) particularly, HPV types 16 and 18 cause cervical cancer and while the two recently developed vaccines against these HPV types are prophylactic in nature, therapeutic options for treatment and management of already existing HPV infection are not available as yet. Because transcription factor, Activator Protein-1 (AP-1) plays a central role in HPV-mediated cervical carcinogenesis, we explored the possibility of its therapeutic targeting by berberine, a natural alkaloid derived from a medicinal plant species, <it>Berberis </it>which has been shown to possess anti-inflammatory and anti-cancer properties with no known toxicity; however, the effect of berberine against HPV has not been elucidated.</p> <p>Results-</p> <p>We studied the effect of berberine on HPV16-positive cervical cancer cell line, SiHa and HPV18-positive cervical cancer cell line, HeLa using electrophoretic mobility gel shift assays, western and northern blotting which showed that berberine could selectively inhibit constitutively activated AP-1 in a dose- and time-dependent manner and downregulates HPV oncogenes expression. Inhibition of AP-1 was also accompanied by changes in the composition of their DNA-binding complex. Berberine specifically downregulated expression of oncogenic c-Fos which was also absent in the AP-1 binding complex. Treatment with berberine resulted in repression of E6 and E7 levels and concomitant increase in p53 and Rb expression in both cell types. Berberine also suppressed expression of telomerase protein, hTERT, which translated into growth inhibition of cervical cancer cells. Interestingly, a higher concentration of berberine was found to reduce the cell viability through mitochondria-mediated pathway and induce apoptosis by activating caspase-3.</p> <p>Conclusion-</p> <p>These results indicate that berberine can effectively target both the host and viral factors responsible for development of cervical cancer through inhibition of AP-1 and blocking viral oncoproteins E6 and E7 expression. Inhibition of AP-1 activity by berberine may be one of the mechanisms responsible for the anti-HPV effect of berberine. We propose that berberine is a potentially promising compound for the treatment of cervical cancer infected with HPV.</p

Infection of human papillomaviruses in cancers of different human organ sites

Clinico-epidemiological and molecular studies have established the casual link between Human Papillomavirus (HPV) infection and cervical cancer as also association of HPV infection with several other cancers. In India, cervical cancer is a leading cancer among women and almost all cases of cervical cancer show prevalence of High Risk (HR)-HPV infection. HPV has been also detected in a significant proportion of oral, esophageal, anal, vaginal, vulvar, and penile cancer and in a small percentage of lung, laryngeal, and stomach cancer in India. Due to lack of organized HPV screening program, insufficient infrastructure and trained manpower and inadequacy in cancer registries, there are not much data available on the countrywide HPV prevalence and its type distribution in different cancers in India. Forthcoming introduction of recently developed HPV vaccines in India given a new urgency to know the prevalence and distribution of various HPV types in different organ sites for the management and monitoring of vaccination program and its impact on prevalence of other cancers. This review, summarizes studies on the prevalence of HPV infection in cancers of different organ sites in India

Anticancer property of Bryophyllum pinnata (Lam.) Oken. leaf on human cervical cancer cells

<p>Abstract</p> <p>Background</p> <p><it>Bryophyllum pinnata </it>(<it>B. pinnata</it>) is a common medicinal plant used in traditional medicine of India and of other countries for curing various infections, bowel diseases, healing wounds and other ailments. However, its anticancer properties are poorly defined. In view of broad spectrum therapeutic potential of <it>B. pinnata </it>we designed a study to examine anti-cancer and anti-Human Papillomavirus (HPV) activities in its leaf extracts and tried to isolate its active principle.</p> <p>Methods</p> <p>A chloroform extract derived from a bulk of botanically well-characterized pulverized <it>B</it>. <it>pinnata </it>leaves was separated using column chromatography with step- gradient of petroleum ether and ethyl acetate. Fractions were characterized for phyto-chemical compounds by TLC, HPTLC and NMR and Biological activity of the fractions were examined by MTT-based cell viability assay, Electrophoretic Mobility Shift Assay, Northern blotting and assay of apoptosis related proteins by immunoblotting in human cervical cancer cells.</p> <p>Results</p> <p>Results showed presence of growth inhibitory activity in the crude leaf extracts with IC₅₀at 552 μg/ml which resolved to fraction F4 (Petroleum Ether: Ethyl Acetate:: 50:50) and showed IC₅₀at 91 μg/ml. Investigations of anti-viral activity of the extract and its fraction revealed a specific anti-HPV activity on cervical cancer cells as evidenced by downregulation of constitutively active AP1 specific DNA binding activity and suppression of oncogenic c-Fos and c-Jun expression which was accompanied by inhibition of HPV18 transcription. In addition to inhibiting growth, fraction F4 strongly induced apoptosis as evidenced by an increased expression of the pro-apoptotic protein Bax, suppression of the anti-apoptotic molecules Bcl-2, and activation of caspase-3 and cleavage of PARP-1. Phytochemical analysis of fraction F4 by HPTLC and NMR indicated presence of activity that resembled Bryophyllin A.</p> <p>Conclusions</p> <p>Our study therefore demonstrates presence of anticancer and anti-HPV an activity in <it>B</it>. <it>pinnata </it>leaves that can be further exploited as a potential anticancer, anti-HPV therapeutic for treatment of HPV infection and cervical cancer.</p

Human Papillomavirus Infections in Pregnant Women and Its Impact on Pregnancy Outcomes: Possible Mechanism of Self-Clearance

Young women are at the maximum risk of Human papillomavirus (HPV) infection which are asymptomatic in a majority of cases and spontaneously get cleared. Women in the age between 20 and 35 years are more active sexually and especially in the developing nations, this age group forms a major cohort among the population of pregnant women. The changed hormonal milieu and immune response during pregnancy might favor presence or persistence of HPV infection, while at the same time natural clearance also takes place during pregnancy with an unknown mechanism. Various HPVs have been reported to be associated with preterm rupture of membranes (PROM), fetal growth restriction (FGR), preeclampsia, placental abnormalities and preterm delivery in several populations. The risk factors involved in the intrauterine environment affects fetal development and thus increase the development risk of specific diseases in adult life as per the hypothesis of the fetal origins of adult disease (FOAD). The structural and molecular changes in the feto-maternal interface support and protect the semiallogeneic fetus from immune-mediated or inflammatory injury. On the other hand, the trophoblast cells of placenta facilitate the replication of HPV and the affliction of placenta and the vaginal infection can directly be associated with pregnancy outcomes. So, to optimize better child health care and reproductive outcomes, HPV screening might help during pregnancy. It is therefore important to understand how the HPV is affecting the early pregnancy and immune cells within the feto-maternal interface are educated for self-clearance to fulfill their biological functions or prevalence to affect the pregnancy outcomes and how the persistence of HR-HPV infection overtime increases the development of cervical cancer risk

Differentially localized survivin and STAT3 as markers of gastric cancer progression: Association with Helicobacter pylori

BackgroundLocalization and differential expression of STAT3 and survivin in cancer cells are often related to distinct cellular functions. The involvement of survivin and STAT3 in gastric cancer has been reported in separate studies but without clear understanding of their kinetics in cancer progression.MethodsWe examined intracellular distribution of STAT3 and survivin in gastric adenocarcinoma and compared it with normal and precancer tissues using immunoblotting and immunohistochemistry.ResultsAnalysis of a total of 156 gastric samples comprising 61 histologically normal, 30 precancerous tissues (comprising intestinal metaplasia and dysplasia), and 65 adenocarcinomas, collected as endoscopic biopsies from treatment naïve study participants, revealed a significant (P < .001) increase in overall protein levels. Survivin expression was detectable in both cytoplasmic (90.8%) and nuclear (87.7%) compartments in gastric adenocarcinomas lesions. Precancerous dysplastic gastric lesions exhibited a moderate survivin expression (56.7%) localized in cytoplasmic compartment. Similarly, STAT3 and pSTAT3 expression was detected at high level in gastric cancer lesions. The levels of compartmentalized expression of survivin and STAT3/pSTAT3 correlated in precancerous and adenocarcinoma lesions. Although overexpression of these proteins was found associated with the tobacco use and alcohol consumption, their expression invariably and strongly correlated with concurrent Helicobacter pylori infection. Receiver operating characteristic analysis of nuclear survivin, STAT3, and pSTAT3 in different study groups showed acceptable positive and negative predictive values with area under the curve above 0.8 (P < .001).ConclusionOverall, our results suggest that overall increase in survivin and STAT3 and their subcellular localization are key determinants of gastric cancer progression, which can be collectively used as potential disease biomarkers and therapeutic targets for gastric cancer.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144680/1/cnr21004-Supplementary_Methods_20180313.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144680/2/cnr21004-sup-0001-F1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144680/3/cnr21004_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/144680/4/cnr21004.pd

Aberrant expression and constitutive activation of STAT3 in cervical carcinogenesis: implications in high-risk human papillomavirus infection

<p>Abstract</p> <p>Background</p> <p>Recent observations indicate potential role of transcription factor STAT3 in cervical cancer development but its role specifically with respect to HPV infection is not known. Present study has been designed to investigate expression and activation of STAT3 in cervical precancer and cancer in relation to HPV infection during cervical carcinogenesis. Established cervical cancer cell lines and prospectively-collected cervical precancer and cancer tissues were analyzed for the HPV positivity and evaluated for STAT3 expression and its phosphorylation by immunoblotting and immunohistochemistry whereas STAT3-specific DNA binding activity was examined by gel-shift assays.</p> <p>Results</p> <p>Analysis of 120 tissues from cervical precancer and cancer lesions or from normal cervix revealed differentially high levels of constitutively active STAT3 in cervical precancer and cancer lesions, whereas it was absent in normal controls. Similarly, a high level of constitutively active STAT3 expression was observed in HPV-positive cervical cancer cell lines when compared to that of HPV-negative cells. Expression and activity of STAT3 were found to change as a function of severity of cervical lesions from precancer to cancer. Expression of active pSTAT3 was specifically high in cervical precancer and cancer lesions found positive for HPV16. Interestingly, site-specific accumulation of STAT3 was observed in basal and suprabasal layers of HPV16-positive early precancer lesions which is indicative of possible involvement of STAT3 in establishment of HPV infection. In HPV16-positive cases, STAT3 expression and activity were distinctively higher in poorly-differentiated lesions with advanced histopathological grades.</p> <p>Conclusion</p> <p>We demonstrate that in the presence of HPV16, STAT3 is aberrantly-expressed and constitutively-activated in cervical cancer which increases as the lesion progresses thus indicating its potential role in progression of HPV16-mediated cervical carcinogenesis.</p

Human papillomavirus and control of cervical cancer in India

Cervical cancer is the principal cause of cancer-related mortality and is a major reproductive health problem in Indian women. Despite the successful development of vaccines against its causative agent (human papillomavirus [HPV]), which could be used as primary prevention tool, the highly beneficial effects of cervical screening by visual inspection with acetic acid, cytology and recently HPV DNA detection, and advances in technologies for detection of incipient lesions and HPV infection, the problem of cervical cancer is still prevalent in the country. This article reviews the status of HPV and the epidemiology of the major disease that it causes in India with various opportunities, obstacles and efforts to overcome the roadblocks for the control of cervical cancer in resource-limited settings such as India

Anti-human papillomavirus therapeutics: facts &amp; future

Even after 25 years of establishing Human Papillomavirus (HPV) as the causative agent for cervical cancer, effective treatment of HPV infection still unavailable. Comprehensive efforts especially for targeting HPV infection have been made only in recent years. Conventional physical ablation of HPV-induced lesions such as cryo-therapy, photo-therapy, LEEP, laser cone-biopsy and localized radiotherapy are shown to be effective to some extent in treating localized lesions where the removal of diseased tissue is associated with removal of transforming keratinocytes harboring HPV. Apart from currently available prophylactic vaccines which prevent the viral entry and should be given prior to viral exposure, several attempts are being made to develop therapeutic vaccines that could treat prevailing HPV infection. In addition, immunomodulators like interferons and imiquimod that have been shown to elicit cytokine milieu to enhance host immune response against HPV infection. Also, antiviral approaches such as RNA interference (RNAi) nucleotide analogs, antioxidants and herbal derivatives have shown effective therapeutic potential against HPV infection. These leads are being tested in pre-clinical and clinical studies. Present article provides a brief overview of conventional therapies for HPV-associated diseases. Potential of non-ablative anti-HPV treatment modalities that could prove useful for either elimination of HPV in early stages of infection when the virus is not integrated into the host cell genome or suppression of the expression of viral oncogenes that dysregulate the host cell cycle following transformation is discussed

Level of phospho-STAT3 (Tyr705) correlates with copy number and physical state of human papillomavirus 16 genome in cervical precancer and cancer lesions.

Our earlier studies indicated an important role of inducible transcription factor STAT3 in the establishment of persistent infection of human papillomavirus (HPV) type 16 and promotion of cervical carcinogenesis. Since HPV load and its physical state are two potential determinants of this virally-induced carcinogensis, though with some exceptions, we extended our study to examine the role of active STAT3 level in cervical precancer and cancer lesions and it's association with HPV viral load and physical state. An elevated level of active STAT3 was measured by assessing phospho-STAT3-Y705 (pSTAT3), in tumor tissues harboring higher viral load irrespective of the disease grade. Physical state analysis of HPV16 by assessing the degree of amplification of full length E2 and comparing it with E6 (E2:E6 ratio), which predominantly represent episomal form of HPV16, revealed low or undetectable pSTAT3. A strong pSTAT3 immunoreactivity was found in tissues those harbored either mixed or predominantly integrated form of viral genome. Cumulative analysis of pSTAT3 expression, viral load and physical state demonstrated a direct correlation between pSTAT3 expression, viral load and physical state of HPV. The study suggests that there exists a strong clinical correlation between level of active STAT3 expression and HPV genome copy number, and integrated state of the virus that may play a pivotal role in promotion/maintanence of tumorigenic phenotype