Combination therapy application of Abemaciclib with Doxorubicin in triple negative breast cancer cell line MDA-MB-231.

Due to lack of clinical biomarkers, Triple Negative Breast Cancer (TNBC) is more likely to have spread to other tissues at time of diagnosis and therapy planning generally involves use of cytotoxic chemotherapy agents, such as Doxorubicin. We aimed to investigate possible advantages of using combination strategy using Doxorubicin alongside Abemaciclib. After determining the IC50 values for Doxorubicin (DOX) and Abemaciclib (ABE); CompuSyn and ComBenefit software were used to reveal the effect resulting from the combination of two drugs. Following the determined effect, cell death was revealed by fluorescence microscopy and a colony forming assay was performed to see the potential of even a single cancer cell with adhesive character to survive over time and form a clone of itself. Detection of changing antioxidant activity following DOX, ABE and DOX+ABE combination therapy in MDAMB231 cells was determined by measuring MDA, SOD and GSH activities. The expression of Cleaved Caspase 3, PARP, Cleaved PARP, Cdk2 and Bax, which changed as a result of DOX, ABE and DOX+ABE application, was shown by Western Blotting.Cyclin-dependent kinase inhibitors appear as promising agents in therapy planning for breast cancer due to their prominent role in cell cycle regulation, where the number of studies interrogating its efficiency in the treatment of cancer such as TNBC is limited. For this reason, in this study, we aimed to determine the impact of the combined use of the CDK4/6 inhibitors ABE and DOX on the cytotoxicity, apoptotic homeostasis, alterations in antioxidative mechanisms, and the molecular pathways that they utilize. Our results showed that when used in combination, Doxorubicin and Abemaciclib showed a synergistic effect on TNBC cell line MDA-MB-231.

Bag-1L is a stress-withstand molecule prevents the downregulation of Mcl-1 and c-Raf under control of heat shock proteins in cisplatin treated HeLa cervix cancer cells.

BACKGROUND: Cisplatin, a DNA damaging agent, induces apoptosis through increasing DNA fragmentation. However, identification of intrinsic resistance molecules against Cisplatin is vital to estimate the success of therapy. Bag-1 (Bcl-2-associated anthanogene) is one anti-apoptotic protein involved in drug resistance impacting on therapeutic efficiency. Elevated levels of this protein are related with increase cell proliferation rates, motility and also cancer development. For this reason, we aimed to understand the role of Bag-1 expression in Cisplatin- induced apoptosis in HeLa cervix cancer cells. Cisplatin decreased cell viability in time- and dose-dependent manner in wt and Bag-1L+HeLa cells. Although, 10 µM Cisplatin treatment induced cell death within 24h by activating caspases in wt cells, Bag-1L stable transfection protected cells against Cisplatin treatment. To assess the potential protective role of Bag-1, we first checked the expression profile of interacting anti-apoptotic partners of Bag-1. We found that forced Bag-1L expression prevented Cisplatin-induced apoptosis through acting on Mcl-1 expression, which was reduced after Cisplatin treatment in wt HeLa cells. This mechanism was also supported by the regulation of heat shock protein (Hsp) family members, Hsp90 and Hsp40, which were involved in the regulation Bag-1 interactome including several anti-apoptotic Bcl-2 family members and c-Raf.

Alignment of a model amyloid Peptide fragment in bulk and at a solid surface.

The alignment of model amyloid peptide YYKLVFFC is investigated in bulk and at a solid surface using a range of spectroscopic methods employing polarized radiation. The peptide is based on a core sequence of the amyloid beta (Abeta) peptide, KLVFF. The attached tyrosine and cysteine units are exploited to yield information on alignment and possible formation of disulfide or dityrosine links. Polarized Raman spectroscopy on aligned stalks provides information on tyrosine orientation, which complements data from linear dichroism (LD) on aqueous solutions subjected to shear in a Couette cell. LD provides a detailed picture of alignment of peptide strands and aromatic residues and was also used to probe the kinetics of self-assembly. This suggests initial association of phenylalanine residues, followed by subsequent registry of strands and orientation of tyrosine residues. X-ray diffraction (XRD) data from aligned stalks is used to extract orientational order parameters from the 0.48 nm reflection in the cross-beta pattern, from which an orientational distribution function is obtained. X-ray diffraction on solutions subject to capillary flow confirmed orientation in situ at the level of the cross-beta pattern. The information on fibril and tyrosine orientation from polarized Raman spectroscopy is compared with results from NEXAFS experiments on samples prepared as films on silicon. This indicates fibrils are aligned parallel to the surface, with phenyl ring normals perpendicular to the surface. Possible disulfide bridging leading to peptide dimer formation was excluded by Raman spectroscopy, whereas dityrosine formation was probed by fluorescence experiments and was found not to occur except under alkaline conditions. Congo red binding was found not to influence the cross-beta XRD pattern.