Bharath Kumar Velmurugan

Anti-apoptotic and pro-survival effect of protocatechuic acid on hypertensive hearts

Cardiac apoptosis was found in hearts from hypertensive animals, therefore in this study we aimed to evaluate the anti-apoptotic and pro-survival effects of protocatechuic acid (PCA) on hypertensive hearts. At first we found that, sedentary group (SHR)-PCA groups decreased TUNEL-positive apoptotic cells than SHR group alone. Protein levels of Fas ligand, Fas death receptor, Fas-associated death domain (FADD), Bid, t-Bid, Bax, cytochrome c, activated caspase-8, activated caspase 9 and activated caspase-3 were decreased in SHR-PCA group compared with SHR group. Moreover, SHR-PCA groups increased pro-survival pathway proteins like IGF1, pIGF1R, pPI3K, p-Akt, Bcl-xL, and Bcl-2 than SHR and sedentary normotensive group (WKY). All these finding suggest us that, Protocatechuic acid prevented hypertension-enhanced cardiac Fas-dependent and mitochondria-dependent apoptotic pathways and enhanced cardiac pro-survival pathway in rat models.

Activation of estrogen receptors with E2 downregulates peroxisome proliferator-activated receptor γ in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality and occurs more often in men than in women; however, little is known about its underlying molecular mechanisms. The present study investigated the effect of estrogen receptor (ER)α and ERβ on peroxisome proliferator-activated receptor γ (PPARγ) expression in Hep3B cells. We examined PPARγ, ERα and ERβ mRNA and protein expression by RT-PCR and western blotting. In order to determine whether PPARγ plays a central role in HCC, we screened for PPARγ expression in liver cancer patient tissues and differentially differentiated HCC cell lines (HA22T, Huh-7, Hep3B and HepG2). We found that PPARγ expression was highly expressed in liver cancer tissues and in Hep3B cells. Furthermore, overexpression of ERα and ERβ was found to decrease PPARγ expression at the transcriptional as well as at the translational level in a ligand-dependent manner. In summary, the present study demonstrated that both ERα and β were sufficient to inhibit PPARγ and provide a valuable therapeutic option for the treatment of HCC patients.

A review on the effects of current chemotherapy drugs and natural agents in treating non–small cell lung cancer

Lung cancer is the leading cause of cancer deaths worldwide, and this makes it an attractive disease to review and possibly improve therapeutic treatment options. Surgery, radiation, chemotherapy, targeted treatments, and immunotherapy separate or in combination are commonly used to treat lung cancer. However, these treatment types may cause different side effects, and chemotherapy-based regimens appear to have reached a therapeutic plateau. Hence, effective, better-tolerated treatments are needed to address and hopefully overcome this conundrum. Recent advances have enabled biologists to better investigate the potential use of natural compounds for the treatment or control of various cancerous diseases. For the past 30 years, natural compounds have been the pillar of chemotherapy. However, only a few compounds have been tested in cancerous patients and only partial evidence is available regarding their clinical effectiveness. Herein, we review the research on using current chemotherapy drugs and natural compounds (Wortmannin and Roscovitine, Cordyceps militaris, Resveratrol, OSU03013, Myricetin, Berberine, Antroquinonol) and the beneficial effects they have on various types of cancers including non-small cell lung cancer. Based on this literature review, we propose the use of these compounds along with chemotherapy drugs in patients with advanced and/or refractory solid tumours.

Acidic leucine-rich nuclear phosphoprotein-32A (ANP32A) association with lymph node metastasis predicts poor survival in oral squamous cell carcinoma patients

Acidic leucine-rich nuclear phosphoprotein-32A (ANP32A) is a multifunctional protein aberrantly expressed in various types of cancers. However, its expression pattern and clinical significance in oral squamous cell carcinoma (OSCC) remains unclear. In this study, we immunohistochemically investigated the expression pattern of ANP32A in 259 OSCC patients and the results were correlated with clinicopathological factors using Allred, Klein and Immunoreactive scoring (IRS) system. Our data indicated that high expression of ANP32A was significantly associated with N stage and tumor differentiation status in OSCC patients. High ANP32A expression with N2/N3 stage had an increased mortality risk than low ANP32A expressing OSCC patients with N0/N1 stage. Functional studies revealed that knockdown of ANP32A significantly decreased the migration and invasion ability thereby concomitantly increasing E-cadherin and decreasing Slug, Claudin-1 and Vimentin expression in vitro. These results suggest that ANP32A is commonly increased in oral squamous cell carcinoma and ANP32A protein could act as a potential biomarker for prognosis assessment of oral cancer patients with lymph node metastasis.

Helioxanthin suppresses the cross talk of COX-2/PGE2 and EGFR/ERK pathway to inhibit Arecoline-induced Oral Cancer Cell (T28) proliferation and blocks tumor growth in xenografted nude mice

Helioxanthin, an active compound from Taiwania cryptomerioides Hayata, has been shown to have various biological activities. However, their anticancer effect in oral squamous cell carcinoma has not been well established yet. Helioxanthin inhibited the proliferation of oral squamous cell carcinoma cells in a dose‐dependent manner by inducing G2/M phase arrest. Similarly, helioxanthin inhibited cyclooxygenase‐2, (COX‐2), phosphorylated EGFR, and extracellular‐signal‐regulated kinases (ERK) protein level and further reduced the nuclear accumulation of phosphorylated epidermal growth factor receptor (pEGFR) and activator protein‐1(AP‐1) family protein, c‐fos. Moreover, helioxanthin at the dose of 20 and 30 mg kg−1 for 15 days reduced the tumor growth in animal model. This study demonstrated that Helioxanthin exerts its anticancer activity against oral cancer cells by downregulating EGFR/ERK/c‐fos signaling pathway to inhibit COX‐2 level and by activating cyclin‐dependent kinase inhibitor (p27) to further induce G2/M cell cycle arrest. This helioxanthin may serve as a novel candidate for oral cancer prevention.

Toxicity of Doxorubicin (Dox) to different experimental organ systems

&NA; Doxorubicin (Dox) is a valuable anticancer drug for hematologic and solid tumors. Yet, it can cause multi‐organ toxicities in various patients. Since toxicity evaluation is a major criterion to discuss for every experiment, the current mini‐review focuses on the toxicity of Dox to multiple organs and suggests the most probable mechanism. Though several mechanisms have been suggested, the role of oxidative stress remains elusive among other mechanisms and remains the most probable mechanism for cardiotoxic effect of Dox. Graphical abstract Figure. No caption available.

Estrogen and ERα enhanced β-catenin degradation and suppressed its downstream target genes to block the metastatic function of HA22T hepatocellular carcinoma cells via modulating GSK-3β and β-TrCP expression

In our previous experiments, we found β‐catenin was highly expressed in the tumor area with high invasive ability and poor prognosis. In this study, we have examined the mechanism by which ERα regulates β‐catenin expression as well as the metastasis ability of hepatocellular cancer HA22T cells. To identify whether the anticancer effect of estrogen and ERα is mediated through suppression of β‐catenin expression, we co‐transfected pCMV‐β‐catenin and ERα into HA22T cells, and determined the cell motility by wound healing, invasion, and migration assays. Results showed that estrogen and/or ERα inhibited β‐catenin gene expression and repressed HA22T cell motility demonstrated that similar data was observed in cells expressing the ERα stable clone. Moreover, we examined the protein‐protein interaction between ERα and β‐catenin by immunostain, co‐immunoprecipitation, and Western blotting. E2 enhanced the binding of ERα with β‐catenin and then triggered β‐catenin to bind with E3 ligase (βTrCP) to promote β‐catenin degradation. Finally by employing systematic ChIP studies, we showed ERα can interact directly with the β‐catenin promoter region following E2 treatment. All our results reveal that estrogen and ERα blocked metastatic function of HA22T cells by modulating GSK3β and βTrCP expression and further enhanced β‐catenin degradation and suppressed its downstream target genes.

Fenofibrate induced PPAR alpha expression was attenuated by oestrogen receptor alpha overexpression in Hep3B cells

The physiological regulation of Oestrogen receptor α (ERα) and peroxisome proliferator‐activated receptor alpha (PPARα) in Hepatocellular carcinoma (HCC) remains unknown. The present study we first treat the cells with fenofibrate and further investigated the possible mechanisms of 17β‐estradiol (E2) and/or ERα on regulating PPARα expression. We also found higher PPARα expression in the tumor area than adjacent areas and subsequently compared PPARα expression in four different hepatic cancer cell lines. Hep3B cells were found to express more PPARα than the other cell lines. Using the PPARα agonist fenofibrate, we found that fenofibrate increased Hep3B cell proliferation efficiency by increasing cell cycle proteins, such as cyclin D1 and PCNA, and inhibiting p27 and caspase 3 expressions. Next, we performed transient transfections and immuno‐precipitation studies using the pTRE2/ERα plasmid to evaluate the interaction between ERα and PPARα. ERα interacted directly with PPARα and negatively regulated its function. Moreover, in Tet‐on ERα over‐expressed Hep3B cells, E2 treatment inhibited PPARα, its downstream gene acyl‐CoA oxidase (ACO), cyclin D1 and PCNA expression and further increased p27 and caspase 3 expressions. However, over‐expressed ERα plus 17‐β‐estradiol (10−8 M) reversed the fenofibrate effect and induced apoptosis, which was blocked in ICI/melatonin/fenofibrate‐treated cells. This study illustrates that PPARα expression and function were negatively regulated by ERα expression in Hep3B cells.

Preventive effect of celecoxib use against cancer progression and occurrence of oral squamous cell carcinoma

Overexpression of cyclooxygenase-2 in oral cancer increases lymph node metastasis and is associated with a poor prognosis. The potential of celecoxib (CXB) use is reported in cancer treatment by inhibiting proliferation through apoptosis, but the effects on the epithelial-mesenchymal transition (EMT) and cancer cell mobility remain unclear. We performed a preclinical study and population-based study to evaluate CXB use in the prevention of oral cancer progression and occurrence. The in-vitro findings showed that CXB is involved in the inhibition of EMT and cell mobility through blocking transcription factors (Slug, Snail and ZEB1), cytoplasmic mediators (focal adhesion kinase (FAK), vimentin and β-catenin), cell adhesion molecules (cadherins and integrins), and surface receptors (AMFR and EGFR). The murine xenograft model showed a 65% inhibition in tumour growth after a 5-week treatment of CXB compared to placebo. Xenograft tumours in placebo-treated mice displayed a well-to-moderate/moderate differentiated SCC grade, while those from CXB-treated mice were well differentiated. The expression levels of membrane EGFR, and nuclear FAK, Slug and ZEB1 were decreased in the xenograft tumours of CXB-treated mice. A retrospective cohort study showed that increasing the daily dose and medication time of CXB was associated with oral cancer prevention. The findings provide an alternative prevention strategy for oral cancer development with CXB use.

17β-Estradiol and/or estrogen receptor alpha blocks isoproterenol-induced calcium accumulation and hypertrophy via GSK3β/PP2A/NFAT3/ANP pathway

The present study was aimed to investigate the protective effects of 17β-estradiol (E2) and estrogen receptor α (ERα) on isoproterenol (ISO)-treated H9c2 cardiomyoblast cells. In the present study, we treated H9c2 cells with ISO, a β-adrenergic receptor agonist, to induce myocardiac hypertrophy. Pre-administration of E2 or ERα (induced by doxycycline) and E2 plus ERα significantly prevented ISO-induced increase of cell size and cytosolic calcium accumulation, accompanied with increased mRNA of atrial natriuretic peptide and brain natriuretic peptide. However, ICI-ERs antagonist, and melatonin, a specific inhibitor for ERα, reversed the cardioprotective effects, suggesting that E2 action was mediated through ERα. Further evidences showed that E2 and ERα increased the protein level of GSK3β and protein phosphatase 2a inhibitor 2 (I2-PP2A), which subsequently enhanced the activation of I2-PP2A by disrupting PP2A activity and maintains normal calcium outflow. Collectively, E2 and ERα inhibited hypertrophy by preventing cytosol calcium accumulation and by inhibiting the association between PP2A with Na+–Ca2+ exchanger via GSK3β and I2-PP2A activation.