Flavopiridol Induces Apoptosis via Mitochondrial Pathway in B16F10 Murine Melanoma Cells and a Subcutaneous Melanoma Tumor Model

Flavopiridol is a cyclin-dependent kinase (CDK) inhibitor that promotes cell cycle arrest. We aimed to examine the anti-proliferative effects of the flavopiridol and oxaliplatin combination on p16INK4A deficient melanoma cells B16F10 and also its apoptotic effects on a subcutaneously injected B16F10 allograft melanoma tumor model. Flavopiridol and oxaliplatin treated B16F10 cell viability was determined by MTT assay. C57BL6 mice were injected with B16F10 cells and treated with flavopiridol after tumor implantation. BRAF and BCL2L1 mRNA expression levels were measured using reverse transcription-polymerase chain reaction (RT-PCR). Caspase 9 and caspase 3/7 activity were determined by activity assay kits. Proliferating cell nuclear antigen (PCNA) and B-cell lymphoma 2 (BCL-2) protein expression levels were analyzed immunohistochemically. Flavopiridol and oxaliplatin decreased cell death. Flavopiridol enhanced caspase 3/7 and caspase 9 activities in vitro and in vivo in a dose dependent manner via the mitochondrial apoptotic pathway. Even though there was a significant increase in Bcl-2 staining, PCNA staining was decreased in flavopiridol-administered mice. Decreased PCNA expression showed antiproliferative effects of flavopiridol which might be the result of cell-cycle arrest. Flavopiridol can be used as a cell cycle inhibitor, which induced apoptosis through the mitochondrial pathway, independently from BCL2 in B16F10 cells and B16F10 injected C57BL6 allografts. </p

Prevalence of Pseudoexfoliation Syndrome and Pseudoexfoliation Glaucoma in Upper Egypt

<p>Abstract</p> <p>Background</p> <p>Pseudoexfoliation (PXF) is a recognized risk factor for developing cataract, glaucoma and lens dislocation. PXF is also associated with increased risk of complications during cataract surgery due to poor mydriasis and zonular weakness. The aim of this study is to report the prevalence of pseudoexfoliation among Upper Egyptians attending the ophthalmology clinic of Assiut University Hospital.</p> <p>Methodology</p> <p>A retrospective, chart review study conducted in the period from February 2002 to August 2009. A total of 7738 patients aged 40 years or older attending the general ophthalmic clinics were included in this study. A detailed evaluation including ophthalmic and general history, slit lamp biomicroscopy, intraocular pressure measurement, gonioscopy and dilated eye examination were performed. Patients with pseudoexfoliative material on the anterior lens surface and ⁄ or the pupillary margin in either or both eyes were labeled as having PXF.</p> <p>Results</p> <p>Out of the 7738 patients included, three hundred twenty (4.14%) subjects had PXF. Mean age of PXF group was 68.15 years (SD 8.16, range 40-92 years). PXF was bilateral in 82.2% of cases. It was significantly associated with cataract, glaucoma and hearing loss. Of the PXF patients, 65% had cataract, 30.3% had glaucoma and 8.1% had hearing loss.</p> <p>Conclusion</p> <p>Pseudoexfoliation appears to be a common disorder in older individuals in Upper Egypt.</p

Metformin Resistant MDA-MB-468 Cells Exhibit EMT-like Phenotype and Increased Migration Capacity

Abstract Background: Metformin is one of the most prescribed drug for the treatment of type II diabetes. Its anti-proliferative effect is also taken advantage for the treatment of cancer. Despite many of the studies mention the positive effects of metformin in inhibiting the proliferation of cancer cells, there are also studies which questions this idea as well.Methods: In this study, we investigated the most widely studied breast cancer cell lines, ER(+) MCF7 cells, TNBC MDA-MB-231 and MDA-MB468 cells in terms of metastatic behavior under long-term metformin treatment. MCF7, MDA-MB231 and MDA-MB468 cells were gained resistant to metformin starting from 0.2mM to 3.2mM. Results: Compared to MCF7 and MDA-MB231 cell lines, we only observed dramatic changes in MDA-MB468 cells whose morphology has been changed towards mesenchymal like phenotype. Moreoever, migration capacity of these cells were also significanlty increased which were validated at both mRNA and protein levels as well as wound healing assay. In addition EMT like phenotype and increasing migration capacity of metformin resistant MDA-MB468 cells, they exhibited less sensitivity to PI3K inhibitor. Conclusions: All together, our data pointed out that, metformin’s effects should be questioned depending on the subtype of the breast cancer that’s to be treated.</jats:p

Metformin Resistant MDA-MB-468 Cells Exhibit EMT-like Phenotype and Increased Migration Capacity

Abstract Purpose: Metformin is one of the most prescribed drug for the treatment of type II diabetes. Its anti-proliferative effect is also taken advantage for the treatment of cancer. Despite many of the studies mention the positive effects of metformin in inhibiting the proliferation of cancer cells, there are also studies which questions this idea as well.Methods: In this study, we investigated the most widely studied breast cancer cell lines, ER(+) MCF7 cells, TNBC MDA-MB-231 and MDA-MB468 cells in terms of metastatic behavior under long-term metformin treatment. MCF7, MDA-MB231 and MDA-MB468 cells were gained resistant to metformin starting from 0.2mM to 3.2mM. Results: Compared to MCF7 and MDA-MB231 cell lines, we only observed dramatic changes in MDA-MB468 cells whose morphology has been changed towards mesenchymal like phenotype. Moreoever, migration capacity of these cells were also significanlty increased which were validated at both mRNA and protein levels as well as wound healing assay. In addition EMT like phenotype and increasing migration capacity of metformin resistant MDA-MB468 cells, they exhibited less sensitivity to PI3K inhibitor. Conclusions: All together, our data pointed out that, metformin’s effects should be questioned depending on the subtype of the breast cancer that’s to be treated.</jats:p

Role of metformin on base excision repair pathway in p53 wild-type H2009 and HepG2 cancer cells

The antidiabetic agent metformin was shown to further possess chemopreventive and chemotherapeutic effects against cancer. Despite the advances, the underlying molecular mechanisms involved in decreasing tumor formation are still unclear. The understanding of the participation of oxidative stress in the action mechanism of metformin and its related effects on p53 and on DNA base excision repair (BER) system can help us to get closer to solve metformin puzzle in cancer. We investigated the effects of metformin in HepG2 and H2009 cells, verifying cytotoxicity, oxidative stress, antioxidant status, and DNA BER system. Our results showed metformin induced oxidative stress and reduced antioxidant capacity. Also, metformin treatment with hydrogen peroxide (H2O2) enhanced these effects. Although DNA BER enzyme activities were not changed accordantly together by metformin as a single agent or in combination with H2O2, activated p53 was decreased with increased oxidative stress in H2009 cells. Our study on the relationship between metformin/reactive oxygen species and DNA BER system in cancer cells would be helpful to understand the anticancer effects of metformin through cellular signal transduction pathways. These findings can be a model of the changes on oxidative stress that reflects p53’s regulatory role on DNA repair systems in cancer for the future studies. </jats:p

THERAPEUTIC AND GENETIC-ASPECTS OF CONGENITAL GLAUCOMAS

Therapy for congenital glaucoma is primarily surgical. We have investigated 249 cases who have undergone trabeculectomy. There was a 79% success rate as regards to control of the IOP. Vision could be saved among the patients who had applied relatively early. At the end of the follow up which was 5 years IOP remained normal in the successful group. All the patients and their families were analysed genetically by their pedigrees and caryotypes. An autosomal recessive pattern with variable penetrance was found. The majority of the patients came from families with consanguineous marriages giving a rate of 66.6%. It was suggested that the course of the disease is highly affected by and related to parental consanguinity. An early age of onset and an accelerated clinical course could be well correlated