Prognostic and therapeutic potential of STAT3: Opportunities and challenges in targeting HPV-mediated cervical carcinogenesis.

Cervical cancer (CaCx) ranks as the fourth most prevalent cancer among women globally. Persistent infection of high-risk human papillomaviruses (HR-HPVs) is major etiological factor associated with CaCx. Signal Transducer and Activator of Transcription 3 (STAT3), a prominent member of the STAT family, has emerged as independent oncogenic driver. It is a target of many oncogenic viruses including HPV. How STAT3 influences HPV viral gene expression or gets affected by HPV is an area of active investigation. A better understanding of host-virus interaction will provide a prognostic and therapeutic window for CaCx control and management. In this comprehensive review, we delve into carcinogenic role of STAT3 in development of HPV-induced CaCx. With an emphasis on fascinating interplay between STAT3 and HPV genome, the review explores the diverse array of opportunities and challenges associated with this field to harness the prognostic and therapeutic potential of STAT3 in CaCx.

Targeting Cervical Cancer Stem Cells by Phytochemicals.

Cervical cancer (CaCx) poses a significant global health challenge, ranking as the fourth most common cancer among women worldwide. Despite the emergence of advanced treatment strategies, recurrence remains a bottleneck in favorable treatment outcomes and contributes to poor prognosis. The chemo- or radio-therapy resistance coupled with frequent relapse of more aggressive tumors are some key components that contribute to CaCx-related mortality. The onset of therapy resistance and relapse are attributed to a small subset of, slow-proliferating Cancer Stem Cells (CSC). These CSCs possess the properties of tumorigenesis, self-renewal, and multi-lineage differentiation potential. Because of slow cycling, these cells maintain themselves in a semi-quiescent stage and protect themselves from different anti-proliferative anti-cancer drugs. Keeping in view recent advances in their phenotypic and functional characterization, the feasibility of targeting CSC and associated stem cell signaling bears a strong translational value. The presence of CSC has been reported in CaCx (CCSC) which remains a forefront area of research. However, we have yet to identify clinically useful leads that can target CCSC. There is compelling evidence that phytochemicals, because of their advantages over synthetic anticancer drugs, could emerge as potential therapeutic leads to target these CCSCs. The present article examined the potential of phytochemicals with reported anti-CSC properties and evaluated their future in preclinical and clinical applications against CaCx.

In vivo antiangiogenic effect of nimbolide, trans-chalcone and piperine for use against glioblastoma.

BACKGROUND: Angiogenesis is an important hallmark of Glioblastoma (GBM) marked by elevated vascular endothelial growth factor-A (VEGF-A) and its receptor 2 (VEGFR-2). As previously reported nimbolide (NBL), trans-chalcone (TC) and piperine (PPR) possess promising antiangiogenic activity in several cancers however, their comparative efficacy and mechanism of antiangiogenic activity in GBM against VEGFR-2 has not been elucidated. METHODS: 2D and 3D spheroids cultures of U87 (Uppsala 87 Malignant Glioma) were used for evaluation of non-cytotxoic dose for anti-angiogenic activity. The antiangiogenic effect was investigated by the GBM U87 cell line bearing chick CAM model. Excised U87 xenografts were histologically examined for blood vascular density by histochemistry. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the presence of avian and human VEGF-A and VEGFR-2 mRNA transcripts. RESULTS: Using 2D and 3D spheroid models, the non-cytotoxic dose of NBL, TC and PPR was ≤ 11 µM. We found NBL, TC and PPR inhibit U87-induced neoangiogenesis in a dose-dependent manner in the CAM stand-alone model as well as in CAM U87 xenograft model. The results also indicate that these natural compounds inhibit the expression of notable angiogenic factors, VEGF-A and VEGFR-2. A positive correlation was found between blood vascular density and VEGF-A as well as VEGFR-2 transcripts. CONCLUSION: Taken together, NBL, TC and PPR can suppress U87-induced neoangiogenesis via a reduction in VEGF-A and its receptor VEGFR-2 transcript expression at noncytotoxic concentrations. These phytochemicals showed their utility as adjuvants to GBM therapy, with Piperine demonstrating superior effectiveness among them all.

Anti-angiogenic Potential of Trans-chalcone in an In Vivo Chick Chorioallantoic Membrane Model: An ATP Antagonist to VEGFR with Predicted Blood-brain Barrier Permeability.

BACKGROUND: Glioblastoma multiforme (GBM) is characterized by massive tumorinduced angiogenesis aiding tumorigenesis. Vascular endothelial growth factor A (VEGF-A) via VEGF receptor 2 (VEGFR-2) constitutes majorly to drive this process. Putting a halt to tumordriven angiogenesis is a major clinical challenge, and the blood-brain barrier (BBB) is the prime bottleneck in GBM treatment. Several phytochemicals show promising antiangiogenic activity across different models, but their ability to cross BBB remains unexplored. METHODS: We screened over 99 phytochemicals having anti-angiogenic properties reported in the literature and evaluated them for their BBB permeability, molecular interaction with VEGFR-2 domains, ECD2-3 (extracellular domains 2-3) and TKD (tyrosine kinase domain) at VEGF-A and ATP binding site, cell membrane permeability, and hepatotoxicity using in silico tools. Furthermore, the anti-angiogenic activity of predicted lead Trans-Chalcone (TC) was evaluated in the chick chorioallantoic membrane. RESULTS: Out of 99 phytochemicals, 35 showed an efficient ability to cross BBB with a probability score of >0.8. Docking studies revealed 30 phytochemicals crossing benchmark binding affinity <-6.4 kcal/mol of TKD with the native ligand ATP alone. Out of 30 phytochemicals, 12 showed moderate to low hepatotoxicity, and 5 showed a violation of Lipinski's rule of five. Our in silico analysis predicted TC as a BBB permeable anti-angiogenic compound for use in GBM therapy. TC reduced vascularization in the CAM model, which was associated with the downregulation of VEGFR-2 transcript expression. CONCLUSION: The present study showed TC to possess anti-angiogenic potential via the inhibition of VEGFR-2. In addition, the study predicted TC to cross BBB as well as a safe alternative for GBM therapy, which needs further investigation.

Phytochemicals Showing Antiangiogenic Effect in Pre-clinical Models and their Potential as an Alternative to Existing Therapeutics.

Angiogenesis, the formation of new blood vessels from a pre-existing vascular network, is an important hallmark of several pathological conditions, such as tumor growth and metastasis, proliferative retinopathies, including proliferative diabetic retinopathy and retinopathy of prematurity, age-related macular degeneration, rheumatoid arthritis, psoriasis, and endometriosis. Putting a halt to pathology-driven angiogenesis is considered an important therapeutic strategy to slow down or reduce the severity of pathological disorders. Considering the attrition rate of synthetic antiangiogenic compounds from the lab to reaching the market due to severe side effects, several compounds of natural origin are being explored for their antiangiogenic properties. Employing pre-clinical models for the evaluation of novel antiangiogenic compounds is a promising strategy for rapid screening of antiangiogenic compounds. These studies use a spectrum of angiogenic model systems that include HUVEC two-dimensional culture, nude mice, chick chorioallantoic membrane, transgenic zebrafish, and dorsal aorta from rats and chicks, depending upon available resources. The present article emphasizes the antiangiogenic activity of the phytochemicals shown to exhibit antiangiogenic behavior in these well-defined existing angiogenic models and highlights key molecular targets. Different models help to get a quick understanding of the efficacy and therapeutics mechanism of emerging lead molecules. The inherent variability in assays and corresponding different phytochemicals tested in each study prevent their immediate utilization in clinical studies. This review will discuss phytochemicals discovered using suitable preclinical antiangiogenic models, along with a special mention of leads that have entered clinical evaluation.

Exploring Coping and Religiosity in an Indian Ashram for Older Adults.

BACKGROUND AND OBJECTIVES: With the aging of Indians and the cultural context of family care, faith-based ashrams are a possible middle way for older adult care for strained families. Religiosity is multidimensional, but it is unclear how its different dimensions relate to coping. This exploratory study investigates the profile of residents living in a faith-based ashram of Haridwar, a pilgrimage town in Northern India. Additionally, it examines religiosity and coping in this population, and the correlates of positive coping response (PCR). METHODOLOGY: Preliminary field survey helped zero in on a single consenting ashram. We included 95 older adult participants (≥ 60 years) residing for more than six months. Relevant dimensions were captured with a survey interview form to record sociodemographics, BriefCOPE, and Duke University Religion Index. The sample was representative of the institutionalized older-adult population considering the overlap of sociodemographics (age, gender, and marital status). We conducted linear regression to examine possible predictors of PCR. RESULTS: Most older adults were Hindus, higher educated, married, and lived with their spouses. The participants were highly religious. Coping through religion was most common, followed by active coping. On linear regression, a significant model emerged [F (13, 63) = 3.411, p < .001), where age, education, and organizational religious activity were significant predictors of PCR. However, other sociodemographic (sex, marital status, economics, family contact) and dimensions of religiosity (non-organizational religious activity and intrinsic religiosity) variables failed to predict PCR. CONCLUSION: Lesser age, higher education, and involvement in the public practice of religiosity are essential contributors to PCR in older adults. How different aspects of religiosity influence coping and lend meaning to dealing with stress, needs further exploration.

Physical interaction between STAT3 and AP1 in cervical carcinogenesis: Implications in HPV transcription control.

The constitutive activation and aberrant expression of Signal Transducer and Activator of Transcription 3 (STAT3) plays a key role in initiation and progression of cervical cancer (CaCx). How STAT3 influences HPV transcription is poorly defined. In the present study, we probed direct and indirect interactions of STAT3 with HPV16/18 LCR. In silico assessment of cis-elements present on LCR revealed the presence of potential STAT3 binding motifs. However, experimental validation by ChIP-PCR could not confirm any specific STAT3 binding on HPV16 LCR. Protein-protein interaction (PPI) network analysis of STAT3 with other host transcription factors that bind LCR, highlighted the physical association of STAT3 with c-FOS and c-JUN. This was further confirmed in vitro by co-immunoprecipitation, where STAT3 co-immunoprecipitated with c-FOS and c-JUN in CaCx cells. The result was supported by immunocytochemical analysis and colocalization of STAT3 with c-FOS and c-JUN. Positive signals in proximity ligation assay validated physical interaction and colocalization of STAT3 with AP1. Colocalization of STAT3 with c-FOS and c-JUN increased upon IL-6 treatment and decreased post-Stattic treatment. Alteration of STAT3 expression affected the subcellular localization of c-FOS and c-JUN, along with the expression of viral oncoproteins (E6 and E7) in CaCx cells. High expression of c-JUN in tumor tissues correlated with poor prognosis in both HPV16 and HPV18 CaCx cohort whereas high expression of STAT3 correlated with poor prognosis in HPV18 CaCx lesions only. Overall, the data suggest an indirect interaction of STAT3 with HPV LCR via c-FOS and c-JUN and potentiate transcription of viral oncoproteins.

Chick chorioallantoic membrane: a valuable 3D in vivo model for screening nanoformulations for tumor antiangiogenic therapeutics.

Drug discovery is an extensive process. From identifying lead compounds to approval for clinical application, it goes through a sequence of labor-intensive in vitro, in vivo preclinical screening and clinical trials. Among thousands of drugs screened only a few get approval for clinical trials. Furthermore, these approved drugs are often discontinued due to systemic toxicity and comorbidity at clinically administered dosages. To overcome these limitations, nanoformulations have emerged as the most sought-after strategy to safely and effectively deliver drugs within tumors at therapeutic concentrations. Most importantly, the employment of suitably variable preclinical models is considered highly critical for the therapeutic evaluation of candidate drugs or their formulations. A review of literature from the past 10 years on antiangiogenic nanoformulations shows the employment of limited types of preclinical models mainly the 2-dimensional (2D) monolayer cell culture and murine models as the mainstay for drug uptake, toxicity and efficiency studies. To top it all, murine models are highly expensive, time-consuming and require expertise in handling them. The current review highlights the utilization of the age-old chicken chorioallantoic membrane (CAM), a well-defined angiogenic model in the investigation of antiangiogenic compounds and nanoformulations in an economic framework. For practical applicability, we have evaluated the CAM model to demonstrate the screening of antiangiogenic compounds and that tumor cells can be implanted onto developing CAM for growing xenografts by recruiting host endothelial and other cellular components. In addition, the exploitation of CAM tumor xenograft models for the evaluation of nanoparticle distribution has also been reinforced by demonstrating that intravenously administered iron oxide nanoparticles (IONPs) passively accumulate and exhibit intracellular as well as extracellular compartment accumulation in highly vascular xenografts. Finally, the ethical considerations, benefits, and drawbacks, of using CAM as an experimental model for testing potential therapeutics are also highlighted.

Investigation of molecular mechanisms underlying JAK/STAT signaling pathway in HPV-induced cervical carcinogenesis using 'omics' approach.

The precise mechanism of action of Janus Kinases (JAK)/Signal Transducer and activator of Transcription (STAT) signaling in human papillomavirus (HPV)-associated cervical cancer (CaCx) is poorly defined. The present study dissected the underlying components of JAK/STAT signaling in HPV-positive cervical neoplasms. Whole transcriptome profile of CaCx cohort from TCGA database revealed elevated STAT3 and its impact on CaCx patients' survival. Using the RT2 Profiler PCR Array, we analyzed 84 genes of interest associated with JAK/STAT signaling in mRNA derived from HPV-negative and HPV-positive cervical lesions which revealed 21 differentially expressed genes (DEGs). Analyses of DEGs using the Database for Annotation, Visualization and Integrated Discovery tool indicated maximum genes enriched in immune response and negative regulation of apoptotic process. Protein-protein network analysis indicated IL4, STAT5A, STAT4, and JAK3 to be the key genes in the interaction network. Further, 7 key DEGs (IL4R, IRF1, EGFR, OAS1, PIAS1, STAT4, and STAT5A) were validated in TCGA cohort using R2 platform. These genes were differentially expressed among HPV-positive cervical tissues and their correlation with STAT3 was established. EGFR and IL4R showed a comparatively strong correlation with STAT3 that supports their involvement in pathogenesis of CaCx. Finally, the Kaplan-Meier analysis established the prognostic association of the key DEGs, in CaCx cohort. The STAT3 and associated key genes discovered from our study establish a strong pathogenic role of JAK/STAT3 pathway in HPV-mediated cervical carcinogenesis.

Phytochemicals as Potential Chemopreventive and Chemotherapeutic Agents for Emerging Human Papillomavirus-Driven Head and Neck Cancer: Current Evidence and Future Prospects.

Head and neck cancer (HNC) usually arises from squamous cells of the upper aerodigestive tract that line the mucosal surface in the head and neck region. In India, HNC is common in males, and it is the sixth most common cancer globally. Conventionally, HNC attributes to the use of alcohol or chewing tobacco. Over the past four decades, portions of human papillomavirus (HPV)-positive HNC are increasing at an alarming rate. Identification based on the etiological factors and molecular signatures demonstrates that these neoplastic lesions belong to a distinct category that differs in pathological characteristics and therapeutic response. Slow development in HNC therapeutics has resulted in a low 5-year survival rate in the last two decades. Interestingly, HPV-positive HNC has shown better outcomes following conservative treatments and immunotherapies. This raises demand to have a pre-therapy assessment of HPV status to decide the treatment strategy. Moreover, there is no HPV-specific treatment for HPV-positive HNC patients. Accumulating evidence suggests that phytochemicals are promising leads against HNC and show potential as adjuvants to chemoradiotherapy in HNC. However, only a few of these phytochemicals target HPV. The aim of the present article was to collate data on various leading phytochemicals that have shown promising results in the prevention and treatment of HNC in general and HPV-driven HNC. The review explores the possibility of using these leads against HPV-positive tumors as some of the signaling pathways are common. The review also addresses various challenges in the field that prevent their use in clinical settings.