Immunohistochemical expression of p53 protein and proliferating cell nuclear antigen in hepatocellular carcinoma

Grape seed extract ameliorated Ehrlich solid tumor-induced hepatic tissue and DNA damage with reduction of PCNA and P53 protein expression in mice

This study evaluated the ameliorative potential of grape seed extract (GSE) against Ehrlich solid tumor (EST)-induced hepatic tissue alterations in mice. The control group was infused with physiological saline. The second group received GSE (50 mg/kg day by day orally) for 2 weeks. The third group was subcutaneously injected with 2.5 million of EST cells. The fourth group was injected with EST cells and treated with GSE extract simultaneously. The fifth group was injected with EST cells and kept for 2 weeks until the appearance of a solid tumor, then treated with GSE for 2 weeks. The phytochemical analysis of GSE revealed the presence of total phenols (17.442 mg GAE/g) and total flavonoid (6.687 mg CE/g) with antioxidant activity of 81.506 mg TE/g DPPH. The Ehrlich solid tumor significantly raised the activities of ALT, AST, and ALP; the level of alpha fetoprotein (AFP) in serum; and the protein expressions of hepatic proliferating cell nuclear antigen (PCNA) and tumor suppressor protein (P53), as well as induced DNA damage and pathological alterations in liver tissue. However, it significantly reduced serum albumin and total protein levels. In contrast, the co- or post-treatment of EST-bearing mice with GSE reduced the activities of ALT, AST, and ALP; the level AFP in serum; and hepatic P53 and PCNA protein expressions. In addition, it reduced EST-induced hepatic DNA damage and pathological alterations, while it increased serum albumin and total protein levels. This study suggested that GSE is a potent hepatoprotective agent and both co- and post-treatment of EST-bearing mice with GSE almost had the same effects.

Evaluation of the Cardiac Protection Conferred by Proanthocyanidins in Grape Seeds against Development of Ehrlich Solid Tumors in Mice

Examination of the antineoplastic effects of a range of chemical compounds is often undertaken via the transplantable tumor model of Ehrlich solid tumor (EST), which is a simulation of breast cancer. The purpose of this study was to explore how cardiac toxicity, damage, oxidative stress, and changes in the expressions of TNFα and apoptotic P53 triggered by EST could be countered with grape seed proanthocyanidins (GSPE). To that end, 50 female mice were used, with arbitrary and equal distribution into five groups, namely, the control group (G1), GSPE group (G2), EST group (G3), GSPE + EST (G4; cotreatment consisted of mice that received GSPE treatment at the beginning of EST induction over a period of 14 days), and EST + GSPE (G5; posttreatment consisted of mice with EST that received GSPE treatment for 14 days following the 14 days since the induction of EST). By comparison with the control group, the EST group had significantly higher levels of serum lactate dehydrogenase (LDH), creatine phosphokinase (CPK), creatine kinase MB (CK-MB), myoglobin, cardiac TBARS, nitric oxide (NO), total thiol and hydrogen peroxide, cardiac damage, and expression of P53 and TNFα. On the other hand, the EST group had significantly lower levels of cardiac catalase and total antioxidant (TAC) than the control group. Furthermore, better improvement in cardiac toxicity, oxidative stress, damage, apoptosis, and TNFα expressions was displayed by the cotreated (GSPE + EST) group than by the posttreated (EST + GSPE) group. This led to the conclusion that GSPE conferred cardiac protective and antioxidant effects against EST. This finding calls for more investigation on the benefits of grape seeds as adjuvant agents to prevent and treat cardiac toxicity.

Expression and clinicopathological significance of lipin-1 in human breast cancer and its association with p53 tumor suppressor gene

Breast cancer (BC) is an important cause of female cancer-related death. It has recently been demonstrated that metabolic disorders including lipid metabolism are a hallmark of cancer cells. Lipin-1 is an enzyme that displays phosphatidate phosphatase activity and regulates the rate-limiting step in the pathway of triglycerides and phospholipids synthesis. The objective of this study was to evaluate lipin-1 expression, its prognostic significance, and its correlation with p53 tumor suppressor in patients with BC. In this study, 55 pairs of fresh samples of BC and adjacent noncancerous tissue were used to analyze lipin-1, using quantitative real-time polymerase chain reaction and immunohistochemistry (IHC) staining. The expression of other clinicopathological variables and p53 was also examined using IHC technique. The cell migration was studied in MCF-7 and MDA-MB231 cells following the inhibition of lipin-1 by propranolol. Our results show that the relative expression of lipin-1 messenger RNA was significantly higher in BC tissues compared with the adjacent normal tissue and its inhibition reduced cell migration in cancer cells. This upregulation was negatively correlated with histological grade of tumor and p53 status (p = .001 and p = .034) respectively and positively correlated with the tumor size (p = .006). Our results also seem to indicate that the high lipin-1 expression is related to a good prognosis in patients with BC. The expression of lipin-1 may be considered as a novel independent prognostic factor. The inhibition of lipin-1 may also have therapeutic significance for patients with BC. The correlation between lipin-1 and p53 confirms the role of p53 in the regulation of lipid metabolism in cancer cells.

Grape seeds proanthocyanidin extract ameliorates Ehrlich solid tumor induced renal tissue and DNA damage in mice

The current study was carried out to evaluate the protective effect of grape seed proanthocyanidins extract (GSPE) against Ehrlich solid tumor (EST) induced renal injury, with the respect to DNA fragmentation and P53 and PCNA proteins expression in renal tissue. A total of 50 female mice were randomly assigned into five groups. Control mice were injected with physiological saline solution. Mice of the 2^nd group were administered with GSPE (50 mg/kg bw/every 2day/per OS) for 2 weeks and injected with physiological saline solution. Mice of the 3^rd group were injected subcutaneously with 2.5 million cells of EAC/mouse. Mice of the 4^th group were injected with EAC as the 3^rd group and administered with GSPE as the 2^nd group simultaneously for 2 weeks. Mice of the 5^th group were injected with EAC as the 3^rd group and left for 2 weeks (till development of solid tumor), then treated with GSPE for another 2 weeks. EST significantly increased serum levels of urea, creatinine, potassium and chloride. In addition, it induced renal tissue and DNA injuries and increased P53, PCNA and ki67 proteins expression in renal tissues. On the other hand, it decreased serum levels of sodium and calcium ions. However, treatment of EST bearing mice with GSPE normalized serum levels of the above-mentioned parameters and improved renal tissue structure and reduced renal tissue DNA damage and P53, PCNA and ki67 proteins expression. These results indicated that GSPE is a promising nephron protective agent against EST induced renal injury.

P21/WAF1 is an independent survival prognostic factor for patients with hepatocellular carcinoma after resection

BACKGROUND/AIMS

The cyclin kinase inhibitor p21/WAF1 is regulated by p53-dependent or independent pathways and inhibits the action of proliferating cell nuclear antigen (PCNA). The prognostic role of p21/WAF1 in hepatocellular carcinoma (HCC) is ambiguous. To further clarify this, we examined the expression of three genes in HCC.

METHODS

A total of 122 resected HCC specimens were collected from 1987 to 1998. Expression of p21/WAF1, p53, and PCNA in HCC was analysed by immunohistochemistry.

RESULTS

Immunoreactivity was detectable for p21/WAF1 in 37%, and for p53 in 41.8% of HCCs. Positive expression of both genes does not relate to each other, but both are associated with a high PCNA labelling index (LI) (P<0.05) in tumour. p53 (+) is also associated with high serum alpha-foetoprotein (alphaFP) (P<0.001), tumour dedifferentiation (P=0.001) and advanced pathologic stages (P=0.017). However, p21/WAF1 (+) did not show clinicopathologic significance. Survival analysis indicated that poor prognostic factors were p21/WAF1 (-) (P=0.024), p53 (+) (P=0.008), high PCNA (P<0.001), tumour without capsule (P=0.001), poor tumour differentiation (P=0.004), advanced pathologic stage (P<0.001), and high serum alphaFP(P<0.001). Independent factors were p21/WAF1 expression, pathologic stage, and PCNA.

CONCLUSION

In HCC, increased proliferation index PCNA is significantly associated with positive p53 and p21/WAF1. But p21/WAF1 expression did not relate to p53 expression. P21/WAF1 (+) is a good event and serves as an independent survival prognostic factor for HCC, which is a novel finding apart from previous reports.

Expression and prognostic role of molecular markers in 99 KIT-positive gastric stromal tumors in Taiwanese

AIM: To elucidate the prognostic role and relationship of three molecular markers such as tumor suppressor gene p53, proliferating cell nuclear antigen (PCNA) and Ki-67 in gastric stromal tumor.

METHODS: A total of 108 surgically resected gastric smooth muscle tumor specimens were collected from January 1987 to December 1999. Immunohistochemical studies were performed on the paraffin sections of 99 of 108 CD117-positive tumors with antibodies of p53, PCNA, and Ki-67. Immunoreactivity of three molecular markers was recorded by labeling index (LI, %) and was analyzed for clinicopathologic and survival correlation.

RESULTS: Of the 99 cases, immunostaining revealed that 52 patients (52.5%) had p53, and 37 patients (37.3%) had Ki-67 immunoreactivity (defined as >10% of LI). All patients (100%) had PCNA immunoreactivity ranging from 12% to 93% of LI, divided into high or low by median. Statistics revealed that LI of three markers positively correlate to each other (P<0.01) and to microscopic tumor mitotic counts (P <0.001). By combination, patients with ≥2 markers (positive or high) in tumors had early tumor recurrence (P <0.001) and unfavorable outcome (P <0.001). Univariate analysis indicated that patients with tumor size >5 cm (P = 0.003), tumor mitosis >5/50 HPF (P < 0.001), p53 immunoreactivity (P  = 0.001), Ki-67 immunoreactivity (P =0.026), high PCNA LI (P =0.015) and male gender (P =0.036) were six predictors for early disease recurrence. Subsequent multivariate analysis revealed that mitotic counts, tumor size, and p53 immunoreactivity were three independent prognostic factors for both disease free and overall survival of patients. By combination of three independent prognostic factors for grouping, we found higher tumor recurrence rate (P <0.001) and shorter survival (P <0.001) existed in groups with increasing factors.

CONCLUSION: We first provide the prognostic value and linkage of three molecular markers in GISTs. The combination of three factors (p53, tumor size, and tumor mitosis) provides a more powerful prediction of prognosis than any single factor does.

VASA is a specific marker for both normal and malignant human germ cells

VASA is so far the only known gene in mammals whose expression is specific for the germ cell lineage. We investigated the presence of VASA mRNA and protein in a series of germ cell tumors of different histologic subtypes and anatomic location, as well as in nongerm cell tumors such as testicular lymphomas and Leydig cell tumors. We detected VASA mRNA (by quantitative RT-PCR) and protein (by immunohistochemical staining) in normal spermatogenesis, seminoma (both classic and spermatocytic), carcinoma in situ (the precursor of classic seminoma and nonseminoma), dysgerminoma, and gonadoblastoma. VASA immunostaining was relatively weak in seminomas and dysgerminomas compared with spermatocytic seminomas, despite similar mRNA levels, suggesting that VASA is regulated in part by post-transcriptional mechanisms. A higher staining intensity compared with the invasive counterparts was observed in the precursor lesions (ie, carcinoma in situ and gonadoblastoma). No VASA mRNA or protein was detectable in nonseminomatous germ cell tumors (such as embryonal carcinoma, teratoma, and yolk sac tumor) and derived cell lines, or nongerm cell tumors such as lymphoma or Leydig cell tumor. These results provide direct evidence that some germ cell tumors retain germ cell characteristics, whereas other tumors of germ cell origin result from differentiation and loss of germ cell identity. Furthermore, these findings suggest that VASA is likely to serve as a useful and highly specific biomarker for germ cell tumors, particularly classic and spermatocytic seminoma/dysgerminoma, including their precursor stages.

Expression and prognostic roles of the G1-S modulators in hepatocellular carcinoma: p27 independently predicts the recurrence

Expression of cell-cycle modulators at the G1-S boundary, retinoblastoma gene product (pRb), p21, p16, p27, p53, cyclin D1, and cyclin E was investigated with 104 hepatocellular carcinomas (HCC), as well as 90 of their adjacent noncancerous lesions and 9 normal liver control specimens. The labeling indices (LI) of pRb, p21, p16, and p27 were higher in HCC lesions than in the adjacent noncancerous lesions and normal controls. Especially, p27 LI in noncancerous lesions was significantly higher than that in normal livers (P =.011). Aberrant p53 expression and cyclin D1 and E overexpression were observed exclusively in HCC lesions. pRb was positive in 85.6% of the HCC cases and was not related to any clinicopathological parameters. The p21 LI was generally low (average, 5.5 +/- 9.8). Although a negative regulator, p21 LI was higher in cases with intrahepatic metastasis (P =.0359). The p16 LI was significantly decreased (P =.0121) in cases with advanced stage. p27 LI was significantly decreased in cases with portal invasion (P =.0409), poor differentiation (P <.0001), larger size (P =.0421), and intrahepatic metastasis (P =.0878, borderline significance). On the other hand, aberrant p53 expression showed positive relationships with poor differentiation (P =.0004) and Ki-67 LI (P =. 0047). Cyclin D1 overexpression was found in 32.6% of the cases and occurred more frequently in those with high Ki-67 LI (P =.0032), pRb expression (P =.0202), poor differentiation (P =.0612, borderline significance), and intrahepatic metastasis (P =.0675, borderline significance). Cyclin E was overexpressed in 35.5% and had positive relationships with Ki-67 LI (P =.0269) and stage (P =.0125). In univariate analysis, cases with p27 LI < 50 (P =.0004), cyclin D1 overexpression (P =.0041), and cyclin E overexpression (P =.0572, borderline significance) showed poorer outcomes for disease-free survival (DFS). In multivariate analysis, p27 expression could be recognized as an independent prognostic marker for DFS. These findings suggest that in HCC: 1) p27 is active against HCC progression in early phases and, possibly, hepatocarcinogenesis as a negative regulator and can be a novel prognostic marker for DFS; and 2) cyclin D1 predominantly works for cell-cycle progression at the G1-S boundary.