Isolation, characterization and stress response of dental plaque forming bacteria

The current work deals with the studies of isolation and characterization of oral biofilm forming bacteria. The major constituent of biofilm other than bacterial cells is the Extracellular Polymeric Slime matrix (EPS) which is secreted by the bacterial cells themselves. Physical properties of biofilms like attachment, mechanical strength, antibiotic resistance can be attributed to EPS matrix. In this study, attempts were made to study the stress response of bacteria isolated and their chemotactic response. Further attempts were made to characterize the EPS matrix by chemical as well as spectroscopic studies. The bacterial strains isolated were characterized to be Staphylococcus aureus, Staphylococcus salivarius, Streptococcus mitis, Streptococcus oralis, Bacillus subtilis by biochemical identification method. SEM micrographs taken confirmed the formation of biofilm. It was observed that cell attachment was maximum when glucose was used as the sole carbon source. Test for biofilm formation in presence of metal salts of Iron and Zinc showed moderate to high inhibition of film formation. The chemotaxis studies carried out in present work indicates the poor response of two strains towards fructose and sucrose. The EPS characterization result indicated the presence of a macromolecular complex constituting of carbohydrate, protein, lipids and nucleic acids

Managing cervical cancer using multifunctional gold nanorods

Introduction: Treatment of cervical cancer, the third most prevalent cancer in women, is challenged by resistance to chemo and radio therapy, organ toxicities and disease relapse which is mainly due to undiagnosed small metastases and failure in monitoring the course of treatment. Imaging is therefore another critical aspect in overall cancer management. We designed a triple combination treatment modality involving photo thermal therapy, EGFR mAb and GW627368X, an EP4 prostanoid receptor antagonist in a single nanoprobe which also serves as an efficient X-ray CT contrast agents. Methodology: Stimuli responsive, GW627368X loaded, EGFR mAb tagged Gold Nanorods(GNRs) were prepared by seed mediated method and characterized by TEM, NMR, IR and UV absorption spectroscopy. Cellular uptake of nanoparticles was studied by flow cytometry and fluorescent imaging. Drug release kinetics was studied prior to in vitro study. Cervical cancer cells, SiHa and ME180, were incubated with GNRs for 45 mins, irradiated with cw-NIR laser (808 nm) for various time periods and incubated for 12 hours. Cellular effects were studied by viability assays, flow cytometry, florescent staining, SEM, ELISA and western blot analysis. The X-ray attenuation property of nanoprobe was demonstrated by CT imaging of GNR incubated cervical cancer cells compared with untreated cells. Results: Due to surface plasmone resonance of GNRs, energy from incident NIR rays are converted into heat inducing apoptosis evident in viability assays further confirmed by flow cytometry, microscopy and western blot. Accumulation of the GNRs around the EGFR overexpressing transformed cells and subsequent uptake was confirmed microscopically and by increase in SSC of cells. EGFR blockade disrupts ligand receptor interaction down regulating survival pathways like Ras/MAPK, PI3K/Akt and JAK/STAT. Stimuli dependent drug release inhibits EP4 receptor in turn down regulating COX-2, PI3K/Akt and angiogenesis. Reduced VEGF, EGF and PGE-2 production was confirmed by ELISA and down regulation of pAkt, pMAPK, pEGFR, COX-2 and EP4 proteins was confirmed by western blot analysis. Prominently distinguishable CT attenuation was obtained with gold nanoprobes compared to untreated cells. Conclusion: EGFR mAb tagged, GW627368X loaded GNRs is novel therapeutic approach merging multiple strategies in single nanoprobe. Besides targeted accumulation, EGFR mAb disrupts EGFR signaling which along with stimuli dependent drug release block multiple downstream pathways. Photothermal therapy is highly efficient, selective approach as NIR has high tissue permeability but is harmless to normal tissue. Moreover, high X-ray atteneuation of gold makes it suitable a CT contrast agent for both diagnosis and monitoring the course of treatment. The proposed modality would thus prove to be highly efficient in overall management of cervical cancer

The Microbiome–Estrogen Connection and Breast Cancer Risk

The microbiome is undoubtedly the second genome of the human body and has diverse roles in health and disease. However, translational progress is limited due to the vastness of the microbiome, which accounts for over 3.3 million genes, whose functions are still unclear. Numerous studies in the past decade have demonstrated how microbiome impacts various organ-specific cancers by altering the energy balance of the body, increasing adiposity, synthesizing genotoxins and small signaling molecules, and priming and regulating immune response and metabolism of indigestible dietary components, xenobiotics, and pharmaceuticals. In relation to breast cancer, one of the most prominent roles of the human microbiome is the regulation of steroid hormone metabolism since endogenous estrogens are the most important risk factor in breast cancer development especially in postmenopausal women. Intestinal microbes encode enzymes capable of deconjugating conjugated estrogen metabolites marked for excretion, pushing them back into the enterohepatic circulation in a biologically active form. In addition, the intestinal microbes also break down otherwise indigestible dietary polyphenols to synthesize estrogen-like compounds or estrogen mimics that exhibit varied estrogenic potency. The present account discusses the potential role of gastrointestinal microbiome in breast cancer development by mediating metabolism of steroid hormones and synthesis of biologically active estrogen mimics

Inflammation induced by human papillomavirus in cervical cancer and its implication in prevention

Many pathological conditions including most cancers show an exacerbated activation of the inflammatory pathways and their sustained maintenance. In cervical carcinogenesis, the hyperactivation of the inflammatory pathways plays an important role in tumorigenesis, progression of the disease from low-grade lesions to invasive cervical cancer as well as in the initiation of other infections such as HIV. Cyclooxygenase-2 (COX-2) is the inducible isoform of cyclooxygenases regulated by growth factors and cytokines, hence overexpressed under inflammatory conditions. Higher levels of COX-2 expression are closely related to a higher incidence of parametrial invasion and lymph node metastases in early-stage uterine cervical cancer. The principal products of COX-2 enzyme, prostanoids, are released from cells and act locally in autocrine and paracrine modes, activating diverse intracellular pathways, which in turn induce cellular proliferation, antiapoptotic activity, angiogenesis and increased metastasis. In the current review, we focus on the role of the viral oncogenic proteins in activation of the COX-2/PGE2 pathway and their clinical implications, a better understanding of which would be helpful in designing newer and more effective therapeutic and preventive strategies for the disease

Role of Omentin in Obesity Paradox in Lung Cancer

Lung cancer remains the second-most-common cancer worldwide and is associated with the highest number of cancer-related mortality. While tobacco smoking is the most important risk factor for lung cancer, many other lifestyles and occupational factors significantly contribute. Obesity is a growing global health concern and contributes to ~30% cancer-related mortality, but unlike other lifestyle diseases, lung cancer is negatively associated with obesity. We meta-analyzed multiple case-control studies confirming increased survival and better outcomes in overweight and obese lung cancer patients. Tumor heterogeneity analysis showed significant enrichment of adipocytes and preadipocytes in normal lungs compared to lung cancers. Interestingly, one of the understudied adipokine, omentin, was significantly and consistently lower in lung neoplasms compared to normal lungs. Omentin has been examined in relation to osteoarthritis, inflammatory bowel disease, cardiovascular diseases, diabetes, chronic liver disease, psoriasis and some other cancers. Aberrant expression of omentin has been reported in solid tumors; however, little is known about its role in lung cancer. We found omentin to be consistently downregulated in lung cancers, and it exhibited a negative correlation with important transcription factors FOXA1, EN1, FOXC1 and ELK4. We, therefore, suggest that omentin may serve as a prognostic factor in lung cancer and explain the “obesity paradox” in lung cancer

The gut microbiota in breast cancer development and treatment: The good, the bad, and the useful!

ABSTRACTRegardless of the global progress in early diagnosis and novel therapeutic regimens, breast carcinoma poses a devastating threat, and the advances are somewhat marred by high mortality rates. Breast cancer risk prediction models based on the known risk factors are extremely useful, but a large number of breast cancers develop in women with no/low known risk. The gut microbiome exerts a profound impact on the host health and physiology and has emerged as a pivotal frontier in breast cancer pathogenesis. Progress in metagenomic analysis has enabled the identification of specific changes in the host microbial signature. In this review, we discuss the microbial and metabolomic changes associated with breast cancer initiation and metastatic progression. We summarize the bidirectional impact of various breast cancer-related therapies on gut microbiota and vice-versa. Finally, we discuss the strategies to modulate the gut microbiota toward a more favorable state that confers anticancer effects

Adiponectin, Obesity, and Cancer: Clash of the Bigwigs in Health and Disease

Adiponectin is one of the most important adipocytokines secreted by adipocytes and is called a “guardian angel adipocytokine” owing to its unique biological functions. Adiponectin inversely correlates with body fat mass and visceral adiposity. Identified independently by four different research groups, adiponectin has multiple names; Acrp30, apM1, GBP28, and AdipoQ. Adiponectin mediates its biological functions via three known receptors, AdipoR1, AdipoR2, and T-cadherin, which are distributed throughout the body. Biological functions of adiponectin are multifold ranging from anti-diabetic, anti-atherogenic, anti-inflammatory to anti-cancer. Lower adiponectin levels have been associated with metabolic syndrome, type 2 diabetes, insulin resistance, cardiovascular diseases, and hypertension. A plethora of experimental evidence supports the role of obesity and increased adiposity in multiple cancers including breast, liver, pancreatic, prostrate, ovarian, and colorectal cancers. Obesity mediates its effect on cancer progression via dysregulation of adipocytokines including increased production of oncogenic adipokine leptin along with decreased production of adiponectin. Multiple studies have shown the protective role of adiponectin in obesity-associated diseases and cancer. Adiponectin modulates multiple signaling pathways to exert its physiological and protective functions. Many studies over the years have shown the beneficial effect of adiponectin in cancer regression and put forth various innovative ways to increase adiponectin levels

pH-degradable and thermoresponsive water-soluble core cross-linked polymeric nanoparticles as potential drug delivery vehicle for doxorubicin

Controlled and efficient delivery of therapeutics to tumor cells is one of the key issues in cancer therapy. In the present work, a new class of water soluble core Cross-linked Polymer Nanoparticles (CLPNs) possessing acid degradable core and thermoresponsive shell was synthesized for pH-triggered delivery of drugs to cancerous cells. The diol groups of the poly(ethylene glycol)-b-poly(N-isopropylacrylamide)-b-poly(glycidyl methacrylate) diol triblock copolymer were utilized to form the core cross-linked polymeric nanoparticles through an arm-first method by reaction with aldehyde functionalized cross-linkers through formation of acetal linkages. The encapsulation efficiency as well as the release properties of these CLPNs was investigated using doxorubicin (DOX), a known anticancer drug. The release was found to be preferable at the desired lysosomal pH (∼5.0) of the cancer cells and below the LCST (∼32°C) of poly(N-isopropylacrylamide) (PNIPA). The cytotoxicities of the precursor polymer as well as the CLPNs were tested on the growth of NIH/3T3, normal mouse fibroblast cells and they were found to be nontoxic. The anticancer activity of the DOX loaded CLPN was confirmed using cervical cancer cell lines HeLa and SiHa by MTT assay, morphological studies and flow cytometry. These studies revealed an increased accumulation of the drug around the nucleus when treated with DOX-loaded CLPN as compared to free DOX along with significant reduction in IC₅₀ of both the cell lines. Thus, these CLPNs are potentially useful for controlled drug delivery in the case of advanced chemotherapeutic applications

Molecular inhibition of prostaglandin E2 with GW627368X: Therapeutic potential and preclinical safety assessment in mouse sarcoma model

Prostaglandin E2, the major COX-2 product, acts via 4 functionally distinct prostanoid receptors, EP(1-4). PGE-2, through its receptors, feeds back to positively increase COX-2 expression augmenting its own synthesis thereby driving angiogenesis, while suppressing apoptosis and innate immunity. In addition to the well characterized PGE2/EP4/cAMP/PKA/CREB, EP4 activation increases GSK3 phosphorylation via PI3K and Akt consequently reducing β-catenin phosphorylation. EP4 induces angiogenesis by enhancing VEGF production via ERK activation. These effects of EP4 are asserted either directly or via EGFR transactivation depending on the type of cancer. In view of the safety concerns regarding long term use of COX-2 inhibitors and to find more effective alternatives, we evaluated the potential of EP4 prostanoid receptor as a target for treating cancer progression using a highly selective EP4 antagonist, 4-(4,9-diethoxy-1,3-dihydro-1-oxo-2H-benz[f]isoindol-2-yl)-N-(phenylsulfonyl)-benzeneacetamide. Oral administration of GW627368X showed significant tumor regression characterized by tumor reduction and induction of apoptosis. Reduction in prostaglandin E2 synthesis also led to reduced level of VEGF in plasma. Regulation of multiple pathways downstream of EP4 was evident by down regulation of COX-2, p-Akt, p-MAPK and p-EGFR. Considering wide distribution of the EP4 prostanoid receptor in major organs and the array of physiological processes it contributes to, the safety profile of the drug was analyzed. No major organ toxicity, immunosupression, behavioral change or change in blood parameters attributable to the drug was observed. The results assert the significance of EP4 prostanoid receptor as a therapeutic target as well as the safety of EP4 blockade by GW627368X