Margin-infiltrating CD20(+) B cells display an atypical memory phenotype and correlate with favorable prognosis in hepatocellular carcinoma.

PURPOSE: The role of infiltrating B cells in hepatocellular carcinoma has been overlooked for many years. This study is aimed to delineate the distribution, prognostic value, and functional status of B cells in human hepatocellular carcinoma. EXPERIMENTAL DESIGN: Immunohistochemistry was used to investigate the distribution and clinical significance of infiltrating CD20(+) B cells in a series of 120 patients with hepatocellular carcinoma. The results were further tested in an independent series of 200 patients with hepatocellular carcinoma. The functional status of CD20(+) B cells was determined by flow cytometry, immunofluorescence, and in vitro coculture assay. RESULTS: Infiltrating CD20(+) B cells were predominantly concentrated in the tumor invasive margin, compared with the peri- and intratumor areas. High density of margin-infiltrating B lymphocytes (MIL-B) positively correlated with small tumor size, absence of vascular invasion, and increased density of CD8(+) T cells (P < 0.05). Survival analyses revealed that increased number of MIL-Bs and their penetration through the tumor capsule were significantly associated with improved overall and recurrence-free survival, and were identified as independent prognosticators for patients with hepatocellular carcinoma (P < 0.05). Importantly, the results were further validated in another independent hepatocellular carcinoma cohort. Moreover, we found that MIL-Bs featured an atypical memory phenotype (IgD(-)IgG(+)CD27(-)CD38(-)), expressed surface markers characteristic of antigen-presenting cells, possessed tumor-killing potential by producing IFN-γ, interleukin 12p40 (IL-12p40), granzyme B, and TRAIL, and acted in cooperation with CD8(+) T cells. CONCLUSIONS: The profile of CD20(+) B cells in situ is a new predictor of prognosis for patients with hepatocellular carcinoma and provides a novel target for an optimal immunotherapy against this fatal malignancy.

Identification of side population cells in human hepatocellular carcinoma cell lines with stepwise metastatic potentials.

PURPOSE: To identify the side population (SP) cells from four hepatocellular carcinoma (HCC) cell lines with stepwise metastatic potentials. METHODS: SP cells were sorted from HCCLM3, MHCC97-H, MHCC97-L and Hep3B by flow cytometry, and then analyzed by differentiation study, clonogenic assay, chemoresistance study and tumorigenicity assay in vivo. The expression of ABCG(2) in SP cells was detected by immunocytochemistry, western blotting and real-time quantitative PCR, respectively. RESULTS: There was significant difference in SP proportion among HCCLM3, MHCC97-H, MHCC97-L and Hep3B (28.7 +/- 1.6%, 14.5 +/- 0.6%, 4.2 +/- 0.4%, 0.9 +/- 0.1%, respectively, P < 0.01). All the SP cells showed similar characteristics of self-renewal, high clonogenicity, remarkable chemo-resistance and high expression of ABCG(2). As low as 2,000 SP cells could initiate tumors in non-obese diabetic/severe combined immunodeficiency mice successfully. CONCLUSIONS: SP cells purified from HCC cell lines harbors cancer stem cell-like properties, and may be related to the metastatic potentials and therapeutic-resistance of HCC.

Arsenic trioxide overcomes apoptosis inhibition in K562/ADM cells by regulating vital components in apoptotic pathway.

Extensive researches have revealed that arsenical can exert anti-tumor efficacy against several kinds of cancers including leukemia. Though, little is known about the effects of arsenical on leukemia resistant to chemotherapy, emerging as a serious clinical problem. In this study, we tested arsenic trioxide (As(2)O(3))-induced apoptosis in K562/ADM multidrug-resistant leukemic cells and investigated its possible mechanisms. Using microscopy, flow cytometry (FCM) and DNA electrophoresis, we found that As(2)O(3) could induce the cells to undergo G2/M phase arrest and apoptosis. Further, it was shown that the levels of FAS and P53 proteins increased and P-glycoprotein (P-gp) decreased upon drug action by employing FCM. Reverse transcription polymerase chain reaction (RT-PCR) detected increased mRNA product of FAS and caspase-3 genes and reduced MDR1 mRNA. CASPASE-3 activity was also enhanced after As(2)O(3) treatment. However, the expression of BCL-2 protein was not affected by the drug. Taken together, As(2)O(3) is able to reverse the apoptosis resistance in drug-resistant K562/ADM cells by modulating expression or activity of key factors associated with apoptosis induction.