A green tea polyphenol, epigalocatechin-3-gallate, induces apoptosis of human hepatocellular carcinoma, possibly through inhibition of Bcl-2 family proteins.

BACKGROUND/AIMS: A major polyphenol of green tea, epigallocatechin-3-gallate (EGCG), has previously been shown to induce cell-cycle arrest and apoptosis in various cancers. However, little is known about its effects on hepatocellular carcinomas (HCCs). METHODS: Four HCC cell lines, HLE, HepG2, HuH-7 and PLC/PRF/5, were treated with EGCG or vehicle. Cell viability was assessed by trypan blue staining and WST-8 assay. Cell-cycle, apoptosis and apoptosis-related proteins in HLE cells were evaluated by flow cytometry and Western blotting. The effect of EGCG was also studied in vivo using a xenograft model. The effect of co-treatment with EGCG and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) was also assessed. RESULTS: EGCG inhibited the growth of all HCC cell lines at concentrations of 50-100 microg/ml. In HLE cells, EGCG induced apoptosis but not cell-cycle arrest and appears to have down-regulated Bcl-2alpha and Bcl-xl by inactivation of NF-kappaB. Oral administration of EGCG showed similar effects in HLE xenograft tumors. Co-treatment with EGCG and TRAIL synergistically induced apoptosis in HLE cells. CONCLUSIONS: EGCG induced apoptosis in HLE cells, both in vitro and in vivo. Moreover, it enhanced TRAIL-induced apoptosis. Therefore, EGCG treatment may be useful for improving the prognosis of HCCs.

[Successful hematologic reconstitution using CD34+ cells positively selected from cryopreserved autologous peripheral blood stem cells in a patient with malignant lymphoma].

Clinical use of CD34+ cells positively selected from cryopreserved peripheral blood stem cells (PBSC) has been limited, and there have been only a few reports of this procedure, mainly because clump formation decreases the proportion of CD34+ cells that can be recovered. A 49-year-old Japanese woman with non-Hodgkin's lymphoma (NHL) (follicular mixed, B cell, stage IVA) was treated with seven cycles of conventional chemotherapy and achieved partial remission. During hematopoietic recovery after the seventh course of chemotherapy, PBSC were harvested by continuous leukapheresis and cryopreserved. However, clonal rearrangement of the immunoglobulin heavy chain gene was detected in the PBSC by Southern blot analysis. After high-dose chemotherapy, CD34+ cells were positively immunoselected from the cryopreserved PBSC and infused into the patient at 1.97 x 10(6)/kg. The overall purity and recovery rate of the CD34+ cells were 72.2% and 65.0%, respectively. There were no severe adverse effects after PBSC transplantation, and the time required for recovery of neutrophils to over 0. 5 x 10(9)/l and platelets to over 50 x 10(9)/l was 11 and 21 days, respectively. Transplantation of CD34+ cells positively selected from cryopreserved PBSC provides engraftment ability similar to that of unmanipulated PBSC.

[Experimental investigation of 201TlCl-scintigraphy in evaluating therapeutic effect of hyperthermia].

We investigated the usefulness of 201Tl-scintigraphy in the evaluation of therapeutic effect of hyperthermia. Satoh's experimental lung cancer tumors implanted in the right thighs of donryu rats were treated with hyperthermia using water bath. Tumors were heated at 44 degrees C or 46 degrees C for 15 min. 201Tl-scintigraphy was obtained before, immediately after and 24 hrs after treatment. Counts ratio of the tumor to the normal muscle (T/N ratio) was measured by gamma camera. We examined blood flow of the tumor, and relative tumor growth rate, and performed autoradiogram and histopathological examination of the tumor after 201Tl-scintigraphy. Immediately after hyperthermia, T/N ratio and blood flow of the tumor significantly decreased (p < 0.05). Autoradiogram showed that the accumulation of 201TlCl in the tumor decreased diffusely. Histopathological finding showed congestion, thrombosis, and swelling of endothelial cells. These results suggest that the decrease in T/N ratio may be caused by the vascular damage due to hyperthermia. The T/N ratio recovered 24 hrs after hyperthermia but was still lower than that for the control. Autoradiogram showed that 201TlCl greatly accumulated in the viable tumor tissue but was hardly seen in the necrotic tumor tissue. These results suggest that the decrease in T/N ratio may be caused by increase of necrotic areas. The T/N ratio 24 hrs after hyperthermia correlated (r = 0.83) with relative tumor growth rate on 7th day after hyperthermia and, therefore, can be used as an indicator of relative tumor growth rate. 201Tl-scintigraphy can be useful for prediction of therapeutic effect of hyperthermia.

Preclinical evaluation of MKC-442, a highly potent and specific inhibitor of human immunodeficiency virus type 1 in vitro.

MKC-442 (6-benzyl-1-ethoxymethyl-5-isopropyluracil or I-EBU) has recently been identified as a highly potent and specific inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase. Since the compound has favorable pharmacokinetic and toxicity profiles in vivo, we have evaluated MKC-442 for its inhibitory effect on the replication of HIV-1 in various cell cultures, including human peripheral blood lymphocytes and monocyte-macrophages. The 50 and 90% effective concentrations for HIV-1 (HTLV-IIIB strain) replication in MT-4 cells were 15 and 98 nM, respectively. MKC-442 was also inhibitory to HIV-1 replication in peripheral blood lymphocytes and monocyte-macrophages as determined by the production of p24 antigens in the culture supernatant. Fluorescence-activated cell sorter analysis revealed that MKC-442 was equally active against zidovudine-resistant mutants and zidovudine-susceptible strains. Furthermore, combinations of MKC-442 with either 3'-azido-3'-deoxythymidine, 2',3'-dideoxycytidine, or 2',3'-dideoxyinosine synergistically inhibited the replication of HIV-1. Thus, MKC-442 has been considered as a candidate for clinical efficacy studies.