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Mark H Lee

Publications and source records attributed to Mark H Lee.

24 records · Page 2Linked to original sources
PubMed2003

Monensin inhibits the growth of renal cell carcinoma cells via cell cycle arrest or apoptosis.

Previously, we showed that monensin, Na+ ionophore, potently inhibited the growth of acute myelogenous leukemia and lymphoma cells. Here, we demonstrate that monensin inhibited the proliferation of renal cell carcinoma cells with IC50 of about 2.5 micro M. Monensin induced a G1 or a G2-M phase arrest in these cells. When we examined the effects of this drug on ACHN cells, monensin decreased the levels of CDK2, CDK6, cdc2, cyclin A and cyclin B1 proteins. p21 and p27 proteins were increased by monensin. In addition, monensin markedly enhanced the binding of p21 with CDK2 and the binding of p27 with CDK6. Furthermore, the activities of CDK2- and CDK6-associated kinase were reduced in association with hypophosphorylation of Rb protein. Monensin also induced the apoptosis in several renal cell carcinoma cells. Apoptotic process of Caki-2 cells was associated with the changes of Bcl-2, Bcl-XL, caspase-9, caspase-3, caspase-7 proteins as well as mitochondria transmembrane potential (DeltaPsim) loss. Taken together, these results demonstrate for the first time that monensin inhibits the growth of renal cell carcinoma cells via cell cycle arrest or apoptosis.

Antifungal Agents↗
PubMed2003

Trichostatin inhibits the growth of ACHN renal cell carcinoma cells via cell cycle arrest in association with p27, or apoptosis.

We investigated the in vitro effect of trichostatin (histone deacetylase inhibitor) on cell proliferation, cell cycle regulation and apoptosis in renal cell carcinoma cell lines. Trichostatin significantly inhibited the proliferation of all six cell lines examined in dose-dependent manner with IC50 of about 125-250 nM. Trichostatin (72-h incubation) induced a G1 phase arrest in ACHN, Caki-1, Caki-2 and Renca cell lines and a G2-M phase arrest in A498 cells. When we examined the effects of this drug on ACHN cells, trichostatin decreased the levels of CDK4, CDK6, cyclin D1 and cyclin A proteins. p27 protein was increased by trichostatin. In addition, trichostatin markedly enhanced the binding of p27 with CDK2 and CDK4. Furthermore, the activities of CDK2, CDK4- and CDK6-associated kinase were reduced and the lack of the CDK activity was paralleled by increased hypophosphorylation of Rb protein. Trichostatin also induced apoptosis in all the renal cell carcinoma cell lines. Apoptotic process of ACHN cells was associated with the changes of Bcl-2, caspase-9, caspase-3, caspase-7 proteins as well as mitochondria transmembrane potential (deltapsim) loss. Taken together, these results demonstrate that trichostatin inhibits the growth of renal cell carcinoma cells via cell cycle arrest or apoptosis.

Apoptosis↗
PubMed2002

Importance of open lung biopsy in the diagnosis of invasive pulmonary aspergillosis in patients with hematologic malignancies.

Invasive pulmonary aspergillosis is a serious infectious complication in immunocompromised patients. Recent reports indicate its favorable clinical outcomes by early diagnosis with chest computed tomography scan. We retrospectively analyzed our experiences with histopathological evaluation by open lung biopsy in 31 patients (32 cases) with hematologic malignancies, suspected of having invasive pulmonary aspergillosis clinically and radiologically. Although the initial computed tomography findings of all cases were highly indicative of invasive pulmonary aspergillosis by demonstrating nodules or masses with a halo sign (16 cases), segmental area of consolidation with ground-glass attenuation (7 cases), both nodules or masses with a halo sign and segmental area of consolidation with ground-glass attenuation (7 cases) and poorly defined centrilobular nodules (2 cases), we could histopathologically confirm invasive fungal infections only in 17 cases (53.1%) by open lung biopsy. There were 13 cases of invasive pulmonary aspergillosis, two cases of aspergilloma, and two cases of mucormycosis. No fungal hyphae were found in the other 15 cases: organizing pneumonia in seven cases, pulmonary hemorrhage in three cases, brochiolitis obliterans with organizing pneumonia in two cases, and CMV pneumonia, pulmonary tuberculosis, candida pneumonia in one case each, respectively. We could perform open lung biopsy without mortality and significant morbidity. In view of the low positive predictive value of chest computed tomography scan and the very low morbidity of open lung biopsy, this procedure is recommendable for the diagnosis of invasive pulmonary aspergillosis and determination of its treatment.

Adolescent↗
PubMed2002

In vitro bioactivity and degradation behavior of silica xerogels intended as controlled release materials.

Room temperature-processed silica-based sol-gel, termed silica xerogel, is a novel type of controlled release material. As shown previously, these materials are porous, degradable and can release biologically functional molecules in a controlled manner. It was also demonstrated that these materials are biocompatible in vivo. Herein we report on the ability of silica-based xerogels to form a bioactive, apatite-like (AP) surface and the effect of AP surface on the xerogel stability in vitro. Formation of a crystalline, carbonated AP (c-AP) was found on all silica xerogels studied, with or without Ca- and P-oxides. Calcium and phosphate (Ca-P) free xerogels showed long times to Ca-P precipitation and to formation of a detectable AP-layer (up to 2 weeks). In contrast, the times to precipitation were reduced by 2-3 orders of magnitude, and the c-AP layer was formed within 24 h on all Ca-P containing xerogels. Mechanisms of the c-AP formation on these xerogels were similar to those typical for Ca-P based ceramics: dissolution of calcium and phosphate ions, solution oversaturation with respect to AP and subsequent precipitation of bone-like minerals. The presence of the c-AP surface film produced a remarkable surface stabilizing effect: the rates and the amounts of Si release were significantly reduced in comparison to those for xerogels without the film. This evidence of in vitro bioactivity and controlled degradation, combined with previous in vitro and in vivo reports, suggests that silica xerogel is a promising controlled release material.

Apatites↗
PubMed2002

Oxaliplatin and UFT combination chemotherapy in patients with metastatic colorectal cancer.

A phase II study was performed to evaluate the clinical efficacy and toxicity of oxaliplatin combined with uracil and tegafur (UFT) in patients with advanced colorectal cancer previously treated with a fluoropyrimidine-based regimen. From January to December 1999, 34 patients were enrolled in this study. Patients received intravenous oxaliplatin 130 mg/m2 on day 1 and daily oral UFT 350 mg/m2 in 3 divided doses for 21 days and repeated every 21 days. Thirty-one of 34 patients were assessable for response and 32 patients for toxicity. Partial response was observed in four patients and stable disease in six patients. The response rate was 12.9% (95% CI, 3.6-29.8%) and median duration of response was 17 weeks. The median overall survival and progression-free survival of all patients were 26 weeks (range, 3-90+ weeks) and 9 weeks (range, 3-56 weeks), respectively. Sensory neuropathy was the most common toxicity, but there was no severe toxicity (>grade II) except for a case of grade III neutropenia. We conclude that oxaliplatin and UFT combination chemotherapy was well tolerated without significant toxicities. The results of this trial will serve as the basis for designing new clinical trials with a different dose or schedule.

Adenocarcinoma↗