Protumorigenic role of Timeless in hepatocellular carcinoma.

The mammalian timeless (TIM) protein interacts with proteins of the endogenous clock and essentially contributes to the circadian rhythm. In addition, TIM is involved in maintenance of chromosome integrity, growth control and development. Thus, we hypothesized that TIM may exert a potential protumorigenic function in human hepatocarcinogenesis. TIM was overexpressed in a subset of human HCCs both at the mRNA and the protein level. siRNA-mediated knockdown of TIM reduced cell viability due to the induction of apoptosis and G2 arrest. The latter was mediated via CHEK2 phosphorylation. In addition, siRNA-treated cells showed a significantly reduced migratory capacity and reduced expression levels of various proteins. Mechanistically, TIM directly interacts with the eukaryotic elongation factor 1A2 (EEF1A2), which binds to actin filaments to promote tumor cell migration. siRNA-mediated knockdown of TIM reduced EEF1A2 protein levels thereby affecting ribosomal protein biosynthesis. Thus, overexpression of TIM exerts oncogenic function in human HCCs, which is mediated via CHEK2 and EEF1A2.

Comparing prothrombin induced by vitamin K absence-II (PIVKA-II) with the oncofetal proteins glypican-3, Alpha feto protein and carcinoembryonic antigen in diagnosing hepatocellular carcinoma among Egyptian patients.

BACKGROUND: Hepatocellular carcinoma (HCC) is usually asymptomatic in the early stage and does not show elevated alpha-feto protein (AFP). AFP shows 60-80% sensitivity in diagnosing HCC. Glypican3 (GPC-3) is an oncofetal protein that is only detected in HCC cells but not in benign liver tissues, while Carcinoembryonic antigen (CEA) is expressed in various neoplasms including HCC. Although, it is not specific for HCC. Prothrombin induced by vitamin K absence-II (PIVKA-II) is an abnormal prothrombin protein that is increased in the serum of HCC patients. It has higher sensitivity and specificity compared to AFP. The aim of this study is to compare the clinical utility of PIVKA-II with GPC-3, AFP and CEA in diagnosing HCC. PATIENTS AND METHODS: This study included 40 patients with HCC, 10 patients with cirrhosis as a benign control group, and 10 apparently healthy volunteers as normal controls. Serum samples were subjected to routine laboratory investigations, measurement of CEA, AFP using MEIA technique (Axsym), glypican3, and PIVKA-II using ELISA technique in the sera of all patients and controls. RESULTS: All markers showed the highest results in the HCC group. Higher concentrations of PIVKA-II were detected in patients with splenomegaly, and in tumors with size (>3cm). Combination of Glypican-3 and PIVKA-II showed the highest sensitivity, while GPC-3 alone and combination of GPC-3 and AFP showed the highest specificity to differentiate HCC from liver cirrhosis and normal controls. GPC-3, PIVKAII, and combination of both showed the highest sensitivity, while GPC-3 alone showed the highest specificity to differentiate HCC from liver cirrhosis. CONCLUSION: Glypican-3 is the only oncofetal antigen that showed comparable high diagnostic accuracy as PIVKA-II in diagnosing HCC among Egyptian patients.

Role of Ki67 in predicting resistance to adjuvant tamoxifen in postmenopausal breast cancer patients.

INTRODUCTION: Breast cancer (BC) is a major health problem in Egypt and worldwide. Its prognosis depends not only on tumor stage but also on tumor biology. AIM: To correlate the expression of Ki67 with the clinical outcomes of early hormone-receptor positive postmenopausal BC patients who are receiving tamoxifen. METHODS: This cohort study included 70 patients. They were followed up for a minimum of 2 years. Ki67 was assessed on paraffin-embedded blocks using immunohistochemistry methods. RESULTS: The median Ki67 value was 22.5% (IQR, 10%-50%). Ki67 was significantly higher in patients with HER2 positive tumors compared to HER2 negative tumors. After a median follow up period of 53 months, 22 patients (31%) developed disease recurrence either loco-regional or distant in 5.7% and 30%, respectively. Recurrent patients had significantly higher tumor stage, nodal stage and Ki67 values compared to non-recurrent cases. The 2-, 3- and 5-year overall survival (OS) and disease-free survival (DFS) rates were 100% & 91%, 98% & 84% and 77% & 59%, respectively. DFS was significantly worse with higher TNM stage, lower ER expression and higher Ki67 values. OS was significantly worse in patients with Ki67 values ≥ 30%. Ki67 ≥ 30% was an independent predictor of recurrence, poor DFS and OS. CONCLUSION: High Ki67 expression is predictive of poor prognosis and of resistance to adjuvant tamoxifen therapy in postmenopausal BC. We recommend considering Ki67 as one of the risk factors that guide adjuvant treatment decisions.