Effect of glutamine on cisplatin-induced nephrotoxicity and antitumor efficacy in mice

Nephrotoxicity is a dose-limiting factor in clinical use of cisplatin.This study aimed at investigating the protective role of two g1utamine[31n] doses against cisplaun-imlucecI nephrotoxictty in normal mice, and investigating their effect on the antitumor efficacy of ciplatin in mice bearing Ehrlich ascites carcinoma[EAC]. Experiment 1: 60 female albino mice were divided into 6 groups, 10 mice each. The first group received a single i.p. injection with normal saline and served as control. The second group received a single i.p.5 mg/kg body weigt cisplatin injection. The third and fourth groups received oral doses of glutamine 150 and 300mg/kg body weight respectively. The fifth and sixth groups received oral glutamine doses as the third and fourth groups one hour prior to Cs injection respectively. Animals were sacrified 7days after cisplatin injection, sera were collected and kidney were surgically removed and 10% homogenates were prepared for detection of creatinine level, malondialdehyde[MDA], reduced glutathione level[GSH], and glutathione peroxidase[GSH-Px].Experiment II for investigating antitumor efficacy, 60 mice bearing i.p. EAC, were treated as mentioned in experiment I The mean survival time was determined. Experiment III, the effect of such treatments on tumor growth delay was also assessed in 60 mice bearing s.c. EAC. Cisplatin injection alone induced a significant increase in serum creatinine, renal MDA, decrease of GSH levels and GSH-Px activity. Histological examination confirmed renal damage. Pretreatment with glutamine significantly attenuated the disturbance induced by cisplatin in creatinine, MDA, GSH levels, GSH-Px activity in a dose dependent manner. Glutamine in low and high dose reserved the improvement of the mean survival time induced by cisplatin. Moreover, pretreatment with glutamine high dose significantly improved the effect of cisplatin on tumor growth delay. These data suggest that glutamine may decrease the toxicity and oxidative stress of cisplatin, besides improving its antitumor efficacy

p53 Mutation in HCV-genotype-4 associated hepatocellular carcinoma in Egyptian patients

HCV-associated hepatocellular carcinoma [HCC] is a common neoplasm in Egypt where genotype-4 is prevalent. In the present study the incidence and pattern of p53 mutations was assessed in relation to HCV-genotype-4 in Egyptian HCC patients. We investigated 25 HCV positive HCCs for p53 mutations over expression in relation to HCV-N53 by immunohistochemistry, SSCP and sequencing. Genotyping was done using LiPA-Il and TRUGENE 5 NC sequencing kit. Results were correlated to standard clinicopathologic prognostic factors for HCC. Thirteen cases showed p53 overexpression, and 10 showed p53 mutation [13 mutations] by sequencing [72% concordance]. The highest mutation rate was in exons 6 and 7 [30%] followed by exons 5 and 8 [20%]. Mutations included 3 transitions, 5 transversions, 3 deletions, and 2 insertions. All exon 7 mutations were at codon 249 specific for AFB1 [AGG-AGT, Arg-Ser] and codon 248 specific for vinyl chloride contamination [CGG-TGG, Arg-Trp]. Other mutations reported are novel. Immunostaining for HCV N53 was detected in 19 cases independent of p53 mutation. p53 aberrations were significantly associated with poor prognostic factors for HCC. However, no specific pattern for p53 mutations was observed in HCV genotype 4-associated HCC and no significant relation between p53 mutations, HCV-N53 expressions or any HCV sub-genotype-4 sequence

Genetic distance and heterogenecity between quasispecies is a critical predictor to IFN response in Egyptian patients with HCV genotype-4

HCV is one of the major health problem in Egypt, where it is highly prevalent. Genotype 4 is the most common genotype of HCV and its response to treatment is still a controversy. HCV genotype 4 quasispecies diversity within the 5' untranslated region [5'UTR] was studied in a series of 22 native Egyptian patients with chronic hepatitis C virus with no previous treatment who satisfied all NIH criteria for combined treatment of pegylated IFN and ribavirine and was correlated with the outcome of treatment. The study also included 7 control patients with no antiviral treatment. HCV sequencing was done using the TRUGENE HCV 5-NC genotyping kit. At the 48[th] week of treatment, 15 patients [68%] showed virological response. Whereas HCV-RNA was still detected in 7 patients [32%] in this period; of those, 6 experienced a partial virological response followed by viral breakthrough during treatment. Only one patient did not show any virological or chemical response. The four females included in this study were all responders. There was a significant correlation between the response rate and lower fibrosis [p=0.026] as well as the total number of mutation spots [including all the insertions, deletions, transitions and transversions] [p=0.007, p= 0.035]. Patients who responded to interferon treatment had statistically significant less number in both transitions [p=0.007] and the genetic distances between the quasispecies [p= 0.035]. So, viral genetic complexity and variability may play a role in the response to IFN treatment. The consensus alignment of all three groups revealed no characteristic pattern among the three groups. However, the G to A transitions at 160 was observed among non responders who need further study to confirm this observation

Hepatitis c virus and hepatocellular carcinoma

Different etiological factors such as hepatitis viral infection, alcohol, aflatoxin and chemical carcinogens were mentioned in relation to HCC. However, the global distribution of HCC is strongly linked to the prevalence of hepatitis virus infection. The exact pathogenic mechanisms involved in viral-associated HCC are unclear although direct and indirect mechanisms are possible. Direct carcinogenicity is less certain in HCV-Induced HCC since it is a typical RNA virus and therefore the integration of viral genome into host cell chromosomes has not been shown to occur. However, the presence of two conserved potential nuclear localization signals and a DNA binding motif in the HCV core protein suggest a possible functional role as a regulatory element. Moreover, some studies demonstrated that this protein interacts with certain cellular proto-oncogenes at the transcriptional level, resulting in the promotion of cell proliferation and thus affecting normal hepatocyte growth. Therefore the pathogenesis of HCC may be attributed at least in part to the upregulation of hepatocyte growth induced by HCV core protein and other viral proteins like NS3 and NS5. However, the process of malignant transformation represents a dynamic interplay between classes of genes; oncogenes, tumor suppressor genes, mismatch repair genes, genes controlling apoptosis and cell cycle regulatory genes. In conclusion, since the exact mechanism of action of HCV in the context of HCC is still poorly understood, clarification of the molecular basis of viral replication in hepatocytes, the possible genetic and cytogenetic abnormalities that may be induced by the virus were emphasized in this review. Moreover, early detection of hepatocellular changes by molecular biomarkers may help to detect individuals at high risk of development HCC, thus allowing more effective intervention for cure or prevention