The Effects of Synthesized Rhenium Acetylsalicylate Compounds on Human Astrocytoma Cell Lines.

PURPOSE: Because of the scarcity of suitable brain cancer drugs, researchers are frantically trying to discover novel and highly potent drugs free of side effects and drug-resistance. Rhenium compounds are known to be nontoxic and exhibit no drug resistance. For that reason, we have developed a series of novel rhenium acetylsalicylato (RAC or ASP) complexes to test their cytotoxicity on brain cancer cells. Also we have attempted to explore the DNAbinding properties of these compounds because many drugs either directly or indirectly bind to DNA. METHODS: We have treated the RAC series compounds on human astrocytoma brain cancer cell lines and rat normal brain astrocyte cells and determined the efficacy of these complexes through in vitro cytotoxicity assay. We carried out the DNA-binding study through UV titrations of a RAC compound with DNA. Also we attempted to determine the planarity of the polypyridyl ligands of the RAC series compounds using DFT calculations. RESULTS: RAC6 is more potent than any other RAC series compounds on HTB-12 human astrocytoma cancer cells as well as on Glioblastoma Multiforme D54 cell lines. In fact, The IC-50 value of RAC6 on HTB-12 cancer cells is approximately 2 µM. As expected, the RAC series compounds were not active on normal cells. The DFT calculations on the RAC series compounds were done and suggest that the polypyridyl ligands in the complexes are planar. The UV-titrations of RAC9 with DNA were carried out. It suggests that RAC9 and possibly all RAC series compounds bind to minor grooves of the DNA. CONCLUSION: Because of the very low activity of RAC6 on normal cells and low lC50 value of on astrocytoma (HTB-12) cell lines, it is possible that RAC6 and its derivatives may potentially find application in the treatment of brain cancers. The DFT calculations and UV titrations suggest that RAC series compounds either bind to DNA intercalatively or minor grooves of the DNA or both. However, it is highly premature to make any definite statement in the absence of other techniques.

Short Communication: Studying the Role of Smart Flare Gold Nano Particles in Studying Micro RNA and Oncogene Differential Expression in Prostate Cancer Cell Lines.

Nano technology is a cutting edge science which is now effectively used in the field of cancer biology. Smart Flare gold nanoparticles are now used often for differential gene expression analysis. In this manuscript we are reporting the use of micro RNA miR 146a and onco gene EZH2 Smart Flare probes to study their expression in different prostate cancer cell lines and the effect of novel Rhenium compounds on these genes using a flow cytometer and a Fluorescence microscope. Our results showed this novel nanotechnology can be effectively used in cancer biology to successfully detect the effect of novel drugs on oncogenes and could be a very useful tool for next generation of cancer researchers.

Epigenetic approaches in glioblastoma multiforme and their implication in screening and diagnosis.

Epigenetic modifications have been reported in a number of non-germ-line tumor types. Epigenetic modifications to the genome, especially DNA methylation and histone modifications, affect gene expression causing increased risk for cancers and other diseases. We have summarized information about DNA methylation percentages in Glioblastoma multiforme (GBM) line HTB-12, alveolar cell carcinoma, and acute lymphocytic leukemia samples and determined H3 (K27) methyltransferase activity in GBM and leukemia cells and made comparisons to H3 (K27) methyltransferase activity in normal astrocyte, lung, and lymphocyte cells. GBM and alveolar cell carcinoma gDNA possessed lower gDNA methylation percentages compared to normal cells. Methyl-sensitive cut counting analysis (MSCC) showed fold decreases in GBM CpG methylation sites for genes PBK, KIF23, COL6A3, and LOX. There was no significant difference in CpG DNA methylation, but less histone methyltransferase activity in acute lymphocytic leukemia compared to normal cells. GBM possessed increased histone methyltransferase activity compared to normal samples. Challenges in the field in diagnosis and prognosis for cancer risk especially with regard to the results of this work are discussed.

C-6 Ceramide Induces p53 Dependent Apoptosis in Human Astrocytoma Grade4 (Glioblastoma Multiforme) Cells.

Ceramide is composed of sphingosine and a fatty acid found in large concentration within the cell membrane and often acts as a signaling molecule for various functions including programmed cell death. In the present investigation, we observed that C6-ceramide induces p53-dependent apoptosis and effectively killed the Astrocytoma grade4 (Glioblastoma Multiforme) HTB12 cell lines. Ceramide-induced cell death was confirmed by Trypan blue assay which showed about 65% cells dying from ceramide treatment. Apoptosis was confirmed by Caspase3 ELISA assay and DNA fragmentation assay. The p53 induction was confirmed by immunoblot studies. Since C6 Ceramide induces apoptosis in Glioblastoma cells, it may be employed in chemotherapeutic strategy to treat this highly malignant brain cancer.

Immuno-expression of human melanoma stem cell markers in tissues at different stages of the disease.

BACKGROUND: Human cutaneous melanoma can be one of the most aggressive tumors and is extremely resistant to all current therapeutic modalities. Immunohistochemistry (IHC) studies were undertaken to assess independent relative frequency on preferential overexpression and simultaneous expression of four stem cell markers; CD133+, ABCB5+, CD166, and Nestin, at different stages of the disease. MATERIAL AND METHODS: Five-micron sections from paraffin blocks from primary melanoma, lymph node (LN) metastases, distant metastases, benign nevi from non-melanoma patients (NMP), and patients with past history of melanoma (MP) were IHC stained with monoclonal antibodies (mAb) to the four stem cell markers. RESULTS: Overexpression of CD133+ was noted in tissues from LN and distant metastases compared to benign nevi (P < 0.0022, P < 0.013, respectively). Overexpression of ABCB5+ was observed comparing primary melanoma, LN, and distant metastases to benign nevi from NMP (P < 0.0063, P < 0.001, P < 0.00058, respectively). Significant overexpression of ABCB5+ was noted in tissues from LN and distant metastases compared with benign nevi from MP (P < 0.0003, P < 0.0068). None of the benign nevi of NMP demonstrated ABCB5+. CONCLUSIONS: This study clearly shows the existence of a distinct hyperpolarized population of stem cells and may implicate genetic factors in human cutaneous melanoma. Simultaneous overexpression of CD133+ and Nestin could reflect on their origin or lineage association with a neural stem cell. These findings may open new perspectives for therapeutic implication of a melanoma stem cell in specific cancer therapy.