Epigallocatechin-3-gallate Enhances the Efficacy of MicroRNA-34a Mimic and MicroRNA-93 Inhibitor Co-transfection in Prostate Cancer Cell Line.

The potential role of microRNAs (miRNA or MIR) as therapeutic molecules has moved them from basic research to the field of cancer therapy. High expression of miR-93 and low expression of miR-34a have previously been indicated in prostate cancer (PC), which is the second leading cause of cancer-related death in men. Androgen receptor (AR) and prostate-specific antigen (PSA) play key roles in the initiation and progression of this cancer. Therefore, this study aimed to investigate the effects of the transfection and co-transfection of miR-34a mimic and miR-93 inhibitor with or without epigallocatechin-3-gallate (EGCG) on prostate cancer cell line and also to evaluate their effects on the expression of AR, PSA. Human lymph node carcinoma of the prostate (LNCaP) cells were treated with miR-34a mimic or/and miR-93 inhibitor with or without EGCG. Gene or protein expressions were assessed by real-time PCR or western blotting of lysates. The transfection with miR-34a mimics significantly reduced the mRNA expression of AR (p=0.0016), and PSA (p=0.038) compared to the control. Also, the miR-93 inhibitor led to a decrease in the mRNA expression of AR (p=0.0057) and PSA (p>0.05) compared to the control group. Furthermore, the co-transfection, along with EGCG, caused more decrease in both the AR (p<0.001) and the PSA (p=0.003) expression compared with the co-transfection without EGCG. Our study indicates that the reduced expression of AR and PSA in PC cells followed by treatment with miR-34a mimic and miR-93 inhibitor and their combination with EGCG as a natural substance may be a promising therapeutic way for controlling the growth of these malignant cells.

Antitumor and immunomodulatory effects of salvigenin on tumor bearing mice.

Development of agents that specifically kill cancer cells and simultaneously elicit antitumor immune response is a step forward in cancer therapy. Immunostimulation can result in eliminating of the cancer cells; immunotherapy is a promising approach in balancing the immune response by Treg. In the present study, we investigated whether the administration of salvigenin contributes to the augmentation of antitumor immunity and the regression of tumor tissues in a mouse model of breast cancer. Salvigenin was purified from Tanacetum canescens, and its effect on the tumor volume was investigated. The splenocyte proliferation, shifting of cytokine profile, and the presence of naturally-occurring CD4+CD25+Foxp3+ Treg cells were assessed to describe the anti-tumor immune response. Our results demonstrated that a significant decrease in the level of IL-4 and increase in the IFN-γ in the animals treated with salvigenin and significant decreased in the level of splenic CD4+CD25+Foxp3+ T regulatory cells. The cytotoxic and immunomodulatory properties of salvigenin were acknowledged in vivo.

Polymorphisms of glutathione S-transferase M1, T1, and P1 in patients with HBV-related liver cirrhosis, chronic hepatitis, and normal carriers.

OBJECTIVES: Persistent hepatitis B virus (HBV) infection often leads to the development of chronic hepatitis and cirrhosis. The role of host genetic factors in chronic HBV infection is not fully understood. We studied the influence of glutathione S-transferase (GST) M1, T1, and P1 polymorphisms in patients with different stages of HBV infections. METHODS: The sample population included 41 HBV normal carriers, 37 patients with chronic hepatitis, and 38 patients with cirrhosis (infected with HBV) compared to a control group (n = 59). PCR-based procedures were performed in the studied populations to confirm the genotypes of GSTT1, M1, and P1. Odds ratio analysis tests were used for statistical evaluation. RESULTS: We found that the frequency of GSTP1-Val (105)/Val (105) genotype was significantly higher in patients with liver cirrhosis (27%) than HBV normal carriers (2.4%; OR 14.8, 95% CI 1.8-122.5) and the frequency GSTP1-Val (105)/Ile (105) genotype was significantly higher in patients with liver cirrhosis (59.5%) than HBV normal carriers (19.5%; OR 6.1, 95% CI 2.1-16.7). The genotype GSTP1-Val (105)/Val (105) was more frequent in patients with chronic hepatitis (19.4%) than HBV normal carriers (2.4%; OR 9.65, 95% CI 1.1-82.8). Patients with cirrhosis also had a higher frequency of the GSTM1 null genotype (71.1%) than HBV normal carriers (27.5%; OR 6.5, 95% CI 2.4-17.4) and the GSTM1 null genotype was more frequent in patients with chronic hepatitis (64.9%) than HBV normal carriers (27.5%OR 4.9, 95% CI 1.8-12.8). The frequency of GSTT1 genotype was similar in all groups. CONCLUSION: These results suggest that in HBV infection, inheritance of the null GSTM1 and GSTP1-Val (105) polymorphisms involves a host genetic factor that is relevant to disease progression.

Glutathione S-transferases activity in patients with colorectal cancer.

OBJECTIVES: The glutathione S-transferases (GSTs) play a critical role in protecting the colorectal mucosa. We investigated the efficacy of using the GSTs activity of plasma as a biomarker of risk for colorectal cancer. METHODS: GSTs activity was measured in the plasma of control individuals (n=39) and in the plasma, tumor tissue and normal tissue adjacent to a tumor of patients with colorectal cancer taken at colonoscopy (n=60). RESULTS: Mean GSTs activity was significantly (P< 0.01) higher in tumors (242+/- 45 nmol/min mg protein) as compared to normal tissues adjacent to a tumor (84+/- 49 nmol/min mg protein). A significant correlation between normal tissues adjacent to a tumor GSTs with those in malignant tissues was observed (r=0.61). Plasma GSTs activity was significantly (P<0.0001) higher in colorectal cancer patients (164+/-11 nmol/min mL) than those obtained from normal individuals (92+/- 23 nmol/min mL). CONCLUSIONS: GSTs measurement may be useful as a colorectal cancer marker in colorectal cancer, and biopsies obtained at colonoscopy can be used to measure tumor markers.

GSTP1, GSTM1, and GSTT1 genetic polymorphisms in patients with cryptogenic liver cirrhosis.

We investigated glutathione S-transferase (GST) P1 Ile (105) Val, T1, and M1 polymorphisms in 45 patients with documented cryptogenic cirrhosis and 56 healthy control subjects. Polymerase chain reaction-based procedures were performed in the studied populations to confirm the genotypes of GSTT1, M1, and P1. Ile/Val and Val/Val GSTP1 genotypes were more frequent in the patients with cirrhosis (n=39, 87%) than in the control subjects (n=10; 18%) (odds ratio [OR] 34.04; 95% confidence interval [CI] 10.70 to 108.31, P<0.001). Among these patients with cirrhosis, 16 were heterozygous and 23 were homozygous, whereas only one person in the control group was homozygous. The GSTM1 null genotype was also more prevalent in cirrhotic patients than in healthy control subjects (OR 6.83, 95% CI 2.53 to 18.42, P<0.001). The rate of GSTT1 deletion did not show a significant difference between the two groups (OR 2.35, 95% CI 0.76 to 7.28, P=0.111). To our knowledge, this is the first evidence that GSTP1 and GSTM1 polymorphisms may be related to the development of cirrhosis by unknown mechanisms. The significant association of cryptogenic cirrhosis with Val/Val GSTP1 genotype encoding a low detoxification activity protein implicates this polymorphism as a risk factor for the occurrence of the disease.