Changes in the in vitro activity of platinum drugs when administered in two aliquots.

BACKGROUND: The management of ovarian cancer remains a challenge. Because of the lack of early symptoms, it is often diagnosed at a late stage when it is likely to have metastasized beyond ovaries. Currently, platinum based chemotherapy is the primary treatment for the disease. However acquired drug resistance remains an on-going problem. As cisplatin brings about apoptosis by intrinsic and extrinsic pathways, this study aimed to determine changes in activity of platinum drugs when administered in two aliquots as against a bolus and sought to determine association with changes in GSH, speciation of platinum drugs and changes in protein expression. METHODS: The efficacy of administering cisplatin, carboplatin and oxaliplatin in two aliquots with a time gap was investigated in ovarian A2780, A2780(cisR), A2780(ZD0473R) and SKOV-3 cell lines. The cellular accumulation of platinum, level of platinum - DNA binding and cellular glutathione level were determined, and proteomic studies were carried out to identify key proteins associated with platinum resistance in ovarian A2780(cisR) cancer cell line. RESULTS: Much greater cell kill was observed with solutions left standing at room temperature than with freshly prepared solutions, indicating that the increase in activity on ageing was related to speciation of the drug in solution. Proteomic studies identified 72 proteins that were differentially expressed in A2780 and A2780(cisR) cell lines; 22 of them were restored back to normal levels as a result of synergistic treatments, indicating their relevance in enhanced drug action. CONCLUSIONS: The proteins identified are relevant to several different cellular functions including invasion and metastasis, cell cycle regulation and proliferation, metabolic and biosynthesis processes, stress-related proteins and molecular chaperones, mRNA processing, cellular organization/cytoskeleton, cellular communication and signal transduction. This highlights the multifactorial nature of platinum resistance in which many different proteins with diverse functions play key roles. This means multiple strategies can be harnessed to overcome platinum resistance in ovarian cancer. The results of the studies can be significant both from fundamental and clinical view points.

ABO blood group and skin cancers.

Beside the role of ABO group in immunohaematology, there is accumulating evidence that the ABO blood group also plays a key role in various human disorders. The interest in blood groups and their association with disease stems from the awareness that blood group antigens are incredibly important components in the process of cell maturation and control. Studies have indicated a link between cancer and the ABO blood group. The appearance or disappearance of blood type antigens is now considered a hallmark of malignancy in many common cancers. Several tumour markers are in fact known blood group antigens. The aim of this review is to describe the history and possible functions of the ABO group and then summarize the association between blood groups and skin cancers.

A large-scale study exploring understanding of the national premarital screening program among Jordanians: Is an at-risk marriage a valid option for Jordanians?

Detecting carrier couples through premarital screening implementation is an effective way of controlling thalassaemia. The aim of this study was to investigate the knowledge of university students towards premarital screening and their possible involvement in an at-risk marriage. Students (n = 976) were chosen randomly from Jordanian universities. The questionnaire consisted of three sections: socio-demographical data, the students' knowledge about the screening programme, and finally their beliefs and future decisions related to it. Most (90%) participants were aware of the premarital screening availability. Females had significantly better understanding of premarital screening compared to males. Despite the majority of the participants not wanting to go ahead with at-risk marriages, 23% would not be deterred from marrying their anticipated partner and believed engaging in at-risk marriage was a valid idea. We suggest providing more effective educational programmes, genetic counselling and free prenatal diagnosis for at-risk couples.

Artificial Neural Networks Model for Predicting Type 2 Diabetes Mellitus Based on VDR Gene FokI Polymorphism, Lipid Profile and Demographic Data.

Type 2 diabetes mellitus (T2DM) is a multifactorial disease associated with many genetic polymorphisms; among them is the FokI polymorphism in the vitamin D receptor (VDR) gene. In this case-control study, samples from 82 T2DM patients and 82 healthy controls were examined to investigate the association of the FokI polymorphism and lipid profile with T2DM in the Jordanian population. DNA was extracted from blood and genotyped for the FokI polymorphism by polymerase chain reaction (PCR) and DNA sequencing. Lipid profile and fasting blood sugar were also measured. There were significant differences in high-density lipoprotein (HDL) cholesterol and triglyceride levels between T2DM and control samples. Frequencies of the FokI polymorphism (CC, CT and TT) were determined in T2DM and control samples and were not significantly different. Furthermore, there was no significant association between the FokI polymorphism and T2DM or lipid profile. A feed-forward neural network (FNN) was used as a computational platform to predict the persons with diabetes based on the FokI polymorphism, lipid profile, gender and age. The accuracy of prediction reached 88% when all parameters were included, 81% when the FokI polymorphism was excluded, and 72% when lipids were only included. This is the first study investigating the association of the VDR gene FokI polymorphism with T2DM in the Jordanian population, and it showed negative association. Diabetes was predicted with high accuracy based on medical data using an FNN. This highlights the great value of incorporating neural network tools into large medical databases and the ability to predict patient susceptibility to diabetes.

Novel Mechanism of Cytotoxicity for the Selective Selenosemicarbazone, 2-Acetylpyridine 4,4-Dimethyl-3-selenosemicarbazone (Ap44mSe): Lysosomal Membrane Permeabilization.

Selenosemicarbazones show marked antitumor activity. However, their mechanism of action remains unknown. We examined the medicinal chemistry of the selenosemicarbazone, 2-acetylpyridine 4,4-dimethyl-3-selenosemicarbazone (Ap44mSe), and its iron and copper complexes to elucidate its mechanisms of action. Ap44mSe demonstrated a pronounced improvement in selectivity toward neoplastic relative to normal cells compared to its parent thiosemicarbazone. It also effectively depleted cellular Fe, resulting in transferrin receptor-1 up-regulation, ferritin down-regulation, and increased expression of the potent metastasis suppressor, N-myc downstream regulated gene-1. Significantly, Ap44mSe limited deleterious methemoglobin formation, highlighting its usefulness in overcoming toxicities of clinically relevant thiosemicarbazones. Furthermore, Cu-Ap44mSe mediated intracellular reactive oxygen species generation, which was attenuated by the antioxidant, N-acetyl-L-cysteine, or Cu sequestration. Notably, Ap44mSe forms redox active Cu complexes that target the lysosome to induce lysosomal membrane permeabilization. This investigation highlights novel structure-activity relationships for future chemotherapeutic design and underlines the potential of Ap44mSe as a selective anticancer/antimetastatic agent.

Identification of differential anti-neoplastic activity of copper bis(thiosemicarbazones) that is mediated by intracellular reactive oxygen species generation and lysosomal membrane permeabilization.

Bis(thiosemicarbazones) and their copper (Cu) complexes possess unique anti-neoplastic properties. However, their mechanism of action remains unclear. We examined the structure-activity relationships of twelve bis(thiosemicarbazones) to elucidate factors regarding their anti-cancer efficacy. Importantly, the alkyl substitutions at the diimine position of the ligand backbone resulted in two distinct groups, namely, unsubstituted/monosubstituted and disubstituted bis(thiosemicarbazones). This alkyl substitution pattern governed their: (1) Cu(II/I) redox potentials; (2) ability to induce cellular (64)Cu release; (3) lipophilicity; and (4) anti-proliferative activity. The potent anti-cancer Cu complex of the unsubstituted bis(thiosemicarbazone) analog, glyoxal bis(4-methyl-3-thiosemicarbazone) (GTSM), generated intracellular reactive oxygen species (ROS), which was attenuated by Cu sequestration by a non-toxic Cu chelator, tetrathiomolybdate, and the anti-oxidant, N-acetyl-l-cysteine. Fluorescence microscopy suggested that the anti-cancer activity of Cu(GTSM) was due, in part, to lysosomal membrane permeabilization (LMP). For the first time, this investigation highlights the role of ROS and LMP in the anti-cancer activity of bis(thiosemicarbazones).

The efficacy of betulinic acid in triple-negative breast cancer.

PURPOSE: The treatment of triple-negative breast cancer remains a daunting challenge with the standard-of-care treatments eventually failing due to acquired drug resistance, toxic side effects and the presence of a deregulated immune response. New treatments for overcoming these drawbacks include the use of plant extracts. STUDY DESIGN: In this study, the efficacy of betulinic acid, a naturally abundant phytochemical exhibiting anti-inflammatory and anti-proliferative activity, has been evaluated for the treatment of triple-negative breast cancer MDA-MB-231 and MDA-MB-468 cell lines. Furthermore, the ability of betulinic acid to inhibit angiogenesis was also determined. RESULTS: Here, we report that betulinic acid was able to inhibit the inflammatory response, inhibit angiogenesis and cause cell cycle arrest ultimately causing apoptosis in triple-negative breast cancer cells. Our findings support that the identification of naturally occurring anti-tumour compounds may provide a chemotherapeutic approach for the treatment of triple-negative breast cancer. CONCLUSION: Overall, our results provide a molecular basis for the ability of betulinic acid to mediate apoptosis, suppress inflammation and inhibit angiogenesis in triple-negative breast cancer cell lines.

Carboplatin and oxaliplatin in sequenced combination with bortezomib in ovarian tumour models.

BACKGROUND: Ovarian cancer remains an on-going challenge mainly due to the development of drug resistance and also because the cancer is likely to have metastasized at the time of diagnosis. Currently, chemotherapy based on platinum drugs such as cisplatin is the primary treatment for the disease. Copper transporter 1 is involved in the transport of cisplatin into the cell, but is also down-regulated by the drug. Bortezomib, a proteasome inhibitor, has been reported to block this platinum-induced down-regulation of CTR1, so that in the presence of bortezomib, the cellular uptake of platinum drugs may be increased. Increased platinum accumulation may result in increased platinum - DNA binding so that the platinum drug in combination with bortezomib may produce enhanced cell kill. METHODS: In this study the efficacy of the sequential combinations of carboplatin, oxaliplatin and a trans-platinum compound coded as CH1 with BORT on the human ovarian A2780, A2780cisR, A2780ZD0473R and SKOV-3 cancer cell lines was evaluated. The levels of cellular platinum accumulation and platinum-DNA binding were determined following the treatment with these combinations. In order to investigate the effect of the combinations of the formation of ROS, the total and oxidized glutathione levels were also determined. RESULTS: Prevention of copper transporter 1 degradation by bortezomib is found to enhance the cellular accumulation of platinum, the level of Platinum - DNA binding and increases oxidative stress especially in the resistant cell lines. CONCLUSIONS: The results suggest that the prevention of CTR1 degradation by bortezomib may be playing a major role in increasing the cellular uptake of platinum drugs and platinum-DNA binding level. Furthermore, the generation of oxidative stress appears to be a major contributor to the enhanced cell kill.

Modulation of cisplatin cytotoxicity due to its combination with bortezomib and the nature of its administration.

The widely used anticancer drug cisplatin (CS) is believed to cross the cell membrane by passive diffusion, carrier-mediated transport and pinocytosis. One carrier involved in the transport of CS into the cell is the copper transporter CTR1. However, CS is found to trigger the down-regulation of CTR1 and its proteasomal degradation. The proteasome inhibitor bortezomib (Bort) has been reported to block CS-induced down-regulation of CTR1 so that in the presence of Bort, the cellular uptake of CS may be increased. Increased platinum accumulation may result in increased platinum-DNA binding so that CS in combination with Bort may produce pronounced cell kill. In this study, synergism in activity from the sequenced combination of CS and Bort in human ovarian A2780, A2780(cisR) and A2780(ZD0473R) cancer cell lines was studied. We also investigated the effect on cell kill due to the administration of CS in two aliquots with a time gap. Addition of Bort 2 h before CS was found to produce greater cell kill than the converse and the bolus, especially in the resistant A2780(cisR) and A2780(ZD0473R) cell lines, in line with increased platinum accumulation and platinum-DNA binding levels. Thus, the prevention of CTR1 degradation by Bort may play a significant role, especially in the resistant cell lines. Administration of CS in two aliquots with a time gap was also found to maximise the cell kill in the ovarian cancer cell lines. If such findings are found to be true in vivo, the results may be significant clinically.