Calcium/calmodulin-dependent kinase inhibitor induces growth inhibition, cell cycle arrest, and apoptosis in human choriocarcinoma cells.

KN-93, a membrane-permeant calcium/calmodulin- dependent kinase-selective inhibitor, induces apoptosis in some lines of human tumor cells. We investigated the effect of KN-93 in the choriocarcinoma cell line, BeWo. BeWo cells were treated with various concentrations of KN-93, and changes in cell growth, the cell cycle, apoptosis, and related parameters were examined. A WST-1 assay showed that BeWo cells were sensitive to the growth inhibitory effect of KN-93. Cell cycle analysis indicated that exposure to KN-93 decreased the proportion of cells in the S phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by Annexin V staining of externalized phosphatidylserine, by the loss of mitochondrial transmembrane potential, and by antibodies directed against histones from fragmented DNA. This induction occurred in conjunction with the altered expression of genes related to cell growth, malignant phenotype, and apoptosis. These results suggest that KN-93 may serve as a therapeutic agent for the treatment of choriocarcinoma.

Effects of bufalin on the proliferation of human choriocarcinoma cells.

OBJECTIVE: Bufalin is a traditional Chinese medicine, and it induces apoptosis in some lines of human tumor cells. METHODS: We investigated the effect of bufalin in the choriocarcinoma cell line, BeWo. BeWo cells were treated with various concentrations of bufalin, and changes in cell growth, the cell cycle, apoptosis, and related parameters were examined. RESULTS: An 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that BeWo cells were sensitive to the growth inhibitory effect of bufalin. Cell cycle analysis indicated that exposure to bufalin decreased the proportion of cells in the synthesis phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and by the loss of mitochondrial transmembrane potential. This induction occurred in conjunction with the altered expression of genes related to cell growth, malignant phenotype, and apoptosis. CONCLUSIONS: These results suggest that bufalin may serve as a therapeutic agent for the treatment of choriocarcinoma.

Erucylphosphocholine induces growth inhibition, cell cycle arrest, and apoptosis in human choriocarcinoma cells.

A membrane-targeted, lipophilic ether lipid of synthetic phospholipid analog, erucylphosphocholine (ErPC), induces apoptosis in some lines of human tumor cells. We investigated the effect of ErPC in the choriocarcinoma cell line, BeWo. BeWo cells were treated with various concentrations of ErPC, and changes in cell growth, the cell cycle, apoptosis, and related parameters were examined. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that BeWo cells were sensitive to the growth inhibitory effect of ErPC. Cell cycle analysis indicated that exposure to ErPC decreased the proportion of cells in the S phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by Annexin V staining of externalized phosphatidylserine and by the loss of mitochondrial transmembrane potential. This induction occurred in conjunction with the altered expression of genes related to cell growth, malignant phenotype, and apoptosis. These results suggest that ErPC may serve as a therapeutic agent for the treatment of choriocarcinoma.

Synergistic anti-neoplastic effect of AG1478 in combination with cisplatin or paclitaxel on human endometrial and ovarian cancer cells.

AG1478, a potent inhibitor of epidermal growth factor receptor (EGFR), facilitates the induction of cell death in combination with a variety of cytotoxic and chemotherapeutic agents in certain human tumor cell lines. The purpose of this study was to elucidate the effect of AG1478 on three endometrial cancer and two ovarian cancer cell lines as compared to normal human endometrial epithelial cells. Cells were treated with various concentrations of AG1478 alone or in combination with the chemotherapeutic drugs cisplatin or paclitaxel, and the effect of AG1478 on cell growth, the cell cycle and apoptosis was investigated. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay revealed that all the cancer cell lines were sensitive to the growth-inhibitory effect of AG1478. Normal endometrial epithelial cells remained viable after treatment with AG1478 at the same doses as those which induced growth inhibition in the endometrial and ovarian cancer cells. Synergistic anti-neoplastic effects were obtained with a combination of AG1478 and cytostatic drugs. Cell-cycle analysis indicated that exposure to these drugs decreased the proportion of cells in the S-phase and increased the proportion in the sub G0/G1 fractions of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and by loss of mitochondrial transmembrane potential. These results suggest that AG1478 alone or in combination with chemotherapeutic drugs may be a novel therapeutic option for the treatment of endometrial and ovarian cancer.

Anti-neoplastic effect of ß-hydroxyisovalerylshikonin on a human choriocarcinoma cell line.

ß-hydroxyisovalerylshikonin (ß-HIVS), a compound isolated from the traditional asian medicinal herb Lithospermum radix, is an ATP non-competitive inhibitor of protein-tyrosine kinases such as v-Src and EGFR, and has been shown to induce apoptosis in several human tumor cell lines. We investigated the effect of ß-HIVS in the choriocarcinoma cell line, BeWo. BeWo cells were treated with various concentrations of ß-HIVS, and changes in cell growth, the cell cycle, apoptosis, and related parameters were examined. An MTT assay showed that BeWo cells were sensitive to the growth inhibitory effect of ß-HIVS. Cell cycle analysis indicated that exposure to ß-HIVS decreased the proportion of cells in the S phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by Annexin V staining of externalized phosphatidylserine and by the loss of mitochondrial transmembrane potential. This induction occurred in conjunction with the altered expression of genes related to cell growth, malignant phenotype, and apoptosis. These results suggest that ß-HIVS may serve as a therapeutic agent for the treatment of choriocarcinoma.

PK11195 enhances chemosensitivity to cisplatin and paclitaxel in human endometrial and ovarian cancer cells.

The potential anticancer agent 1-(2-chlorophenyl-N-methylpropyl)-3-isoquinolinecarboxamide (PK11195), a translocator protein ligand, facilitates the induction of cell death by a variety of cytotoxic and chemotherapeutic agents in various human tumor cell lines. The purpose of this study was to elucidate the effect of PK11195 on three endometrial cancer cell lines, two ovarian cancer cell lines and normal human endometrial epithelial cells. Endometrial and ovarian cancer cells were treated with various concentrations of PK11195 alone or in combination with chemotherapeutic drugs (cisplatin, paclitaxel), and its effect on cell growth, the cell cycle, apoptosis and related measurements was investigated. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay revealed that all endometrial and ovarian cancer cell lines were sensitive to the growth-inhibitory effect of PK11195, although normal endometrial epithelial cells were viable after treatment with the same doses of PK11195 that induced growth inhibition in endometrial and ovarian cancer cells. Synergistic anti-neoplastic effects were obtained by a combination of PK11195 with cytostatic drugs. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with altered expression of genes related to apoptosis. These results suggest that PK11195 alone or in combination with chemotherapeutic drugs might be a new therapeutic option for the treatment of endometrial and ovarian cancers.

Targeting calcium/calmodulin-dependence kinase I and II as a potential anti-proliferation remedy for endometrial carcinomas.

Calcium/calmodulin-dependent kinase (CaMK) I and II expression in endometrial cancer cells correlates with the malignant potential of this tumor, and CaMKI and II are potential therapeutic targets in endometrial cancer. CaMKI and II expression was significantly associated with PCNA-labeling index, clinical stage, histological grade, the presence of invasion to greater than one-half the myometrium, and clinical outcome. All endometrial cancer cell lines examined were sensitive to the growth-inhibitory effect of KN-93, a membrane-permeant CaMKs-selective inhibitor that is competitive with calmodulin. KN-93 induced the G0/G1 arrest and apoptosis, rising hopes that KN-93 may become a useful treatment for endometrial cancers.

Erucylphosphocholine shows a strong anti-growth activity in human endometrial and ovarian cancer cells.

OBJECTIVES: A membrane-targeted, lipophilic ether lipid of synthetic phospholipid analog, erucylphosphocholine (ErPC) induces apoptosis in some lines of human tumor cells. We investigated the effect of ErPC on three endometrial cancer cell lines, two ovarian cancer cell lines, and normal human endometrial epithelial cells. METHODS: Endometrial and ovarian cancer cells were treated with various concentrations of ErPC, and its effect on cell growth, cell cycle, apoptosis, and related measurements was investigated. RESULTS: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that all endometrial and ovarian cancer cell lines were sensitive to the growth-inhibitory effect of ErPC, although normal endometrial epithelial cells were viable after treatment with the same doses of ErPC that induced growth inhibition in endometrial and ovarian cancer cells. Cell cycle analysis indicated that their exposure to ErPC decreased the proportion of cells in the S-phase and increased the proportion in the G2/M phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with altered expression of genes related to cell growth, malignant phenotype, and apoptosis. CONCLUSIONS: These results suggest that the anticancer activity of ErPC may occur with higher sensitivity of cancer cells compared with normal healthy cells, when using low concentration, rising hopes that ErPC may become a useful adjuvant therapy for endometrial and ovarian cancers.

Bufalin induces growth inhibition, cell cycle arrest and apoptosis in human endometrial and ovarian cancer cells.

Bufalin is a traditional Chinese medicine and it induces apoptosis in certain human tumor cell lines. We investigated the effect of bufalin on three endometrial cancer cell lines, two ovarian cancer cell lines, and on normal human endometrial epithelial cells. Endometrial and ovarian cancer cells were treated with various concentrations of bufalin, and its effect on cell growth, cell cycle, apoptosis, and related measurements was investigated. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that all endometrial and ovarian cancer cell lines were sensitive to the growth-inhibitory effect of bufalin, although normal endometrial epithelial cells were viable after treatment with the same doses of bufalin that induced growth inhibition in endometrial and ovarian cancer cells. Cell cycle analysis indicated that their exposure to bufalin decreased the proportion of cells in the S-phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with the altered expression of genes related to cell cycle and apoptosis. These results suggest that bufalin may become a useful adjuvant therapy for endometrial and ovarian cancers with minimal side effects.

K252a is highly effective in suppressing the growth of human endometrial cancer cells, but has little effect on normal human endometrial epithelial cells.

The furanosylated indolocarbazole K252a belongs to a family of microbial alkaloids that also includes staurosporine, which is known to inhibit proliferation, stimulate apoptosis and induce the cell cycle arrest of cancer cells. To elucidate the involvement of K252a in endometrial cancer, we investigated the effects of K252a on three endometrial cancer cell lines. Endometrial cancer cells were treated with K252a and its effect on cell growth, cell cycle and related measurements was assessed. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays showed that the endometrial cancer cell lines were sensitive to the growth inhibitory effect of K252a, although normal endometrial epithelial cells were viable after treatment with the same doses of K252a that induced the growth inhibition of endometrial cancer cells. Cell cycle analysis indicated that their exposure to K252a decreased the proportion of cells in the S phase and increased the proportion of cells in the G0/G1 phase of the cell cycle. TUNEL assays demonstrated that K252a induced apoptosis. This occurred in concert with an altered expression of p21WAF1 and bcl-2 proteins related to the G0/G1 phase of the cell cycle and apoptosis. These results raise the possibility that K252a may prove to be particularly effective in the treatment of endometrial cancers.

Beta-hydroxyisovalerylshikonin has a profound anti-growth activity in human endometrial and ovarian cancer cells.

OBJECTIVES: Beta-hydroxyisovalerylshikonin (beta-HIVS), a compound isolated from the traditional oriental medicinal herb Lithospermum radix, is an ATP non-competitive inhibitor of protein-tyrosine kinases, such as v-Src and EGFR, and it induces apoptosis in some lines of human tumor cells. We investigated the effect of beta-HIVS on three endometrial cancer cell lines, two ovarian cancer cell lines, and normal human endometrial epithelial cells. METHODS: Endometrial and ovarian cancer cells were treated with various concentrations of beta-HIVS, and its effect on cell growth, cell cycle, apoptosis, and related measurements was investigated. RESULTS: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that all endometrial and ovarian cancer cell lines were sensitive to the growth-inhibitory effect of beta-HIVS, although normal endometrial epithelial cells were viable after treatment with the same doses of beta-HIVS that induced growth inhibition in endometrial and ovarian cancer cells. Cell-cycle analysis indicated that their exposure to beta-HIVS decreased the proportion of cells in the S phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with altered expression of genes related to cell growth, malignant phenotype, and apoptosis. CONCLUSIONS: These results suggest that the anticancer activity of beta-HIVS may occur with higher sensitivity of cancer cells compared with normal healthy cells, when using low concentration, rising hopes that beta-HIVS may become a useful adjuvant therapy for endometrial and ovarian cancers.

Histone deacetylase inhibitors induce growth inhibition, cell cycle arrest and apoptosis in human choriocarcinoma cells.

We investigated the effect of five histone deacetylase inhibitors (HDACIs) on the choriocarcinoma cell line, BeWo. BeWo cells were treated with various concentrations of five HDACIs, and their effects on cell growth, cell cycle, apoptosis, and related measurements were investigated. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assays showed that the BeWo choriocarcinoma cell line was sensitive to the growth inhibitory effect of five HDACIs. Cell cycle analysis indicated that exposure to HDACIs decreased the proportion of cells in the S-phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with altered expression of genes related to cell growth, malignant phenotype, and apoptosis. Furthermore, HDACI treatment of this cell line increased acetylation of H3 and H4 histone tails. These results raise the possibility that HDACIs may prove particularly effective in the treatment of choriocarcinoma.

Apicidin, a novel histone deacetylase inhibitor, has profound anti-growth activity in human endometrial and ovarian cancer cells.

Histone deacetylase inhibitors (HDACIs) can inhibit proliferation, induce cell cycle arrest and stimulate apoptosis of cancer cells. Our purpose was to investigate the antiproliferative effects of a novel HDACI, apicidin, on the Ishikawa endometrial cancer cell line, the SK-OV-3 ovarian cancer cell line and normal human endometrial epithelial cells. Endometrial and ovarian cancer cells were treated with various concentrations of apicidin, and the effects on cell growth, cell cycle, apoptosis and related measurements were investigated. MTT assays showed that all endometrial and ovarian cancer cell lines were sensitive to the growth inhibitory effect of apicidin, although normal endometrial epithelial cells were viable after the treatment with the same doses of apicidin that induced the growth inhibition of endometrial and ovarian cancer cells. Cell cycle analysis indicated that their exposure to apicidin decreased the proportion of cells in S-phase and increased the proportion in G0/G1 and/or G2/M phases of the cell cycle. Induction of apoptosis was confirmed by Annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with the altered expression of p21WAF1, p27KIP1, p16, cyclin A, and E-cadherin. Furthermore, apicidin treatment of these cell lines increased acetylation of H3 and H4 histone tails. These results suggest that apicidin exhibits the antiproliferative effects through selective induction of genes related to cell growth, malignant phenotype, and apoptosis. The findings raise the possibility that apicidin may prove particularly effective in the treatment of endometrial and ovarian cancers.

Application of the nuclear factor-kappaB inhibitor BAY 11-7085 for the treatment of endometriosis: an in vitro study.

Most of the current medical treatments for endometriosis aim to downregulate estrogen activity. However, a high recurrence rate after medical treatment has been the most significant problem. BAY 11-7085, a soluble inhibitor of NK-kappaB activation, has been shown to inhibit cell proliferation and induce apoptosis of a variety of cells. To examine the potential application of BAY 11-7085 in the treatment of endometriosis, we investigated the effects of this agent on the cell proliferation and apoptosis of cultured ovarian endometriotic cyst stromal cells (ECSCs) by a modified methylthiazole tetrazolium assay, a 5-bromo-2'-deoxyuridine incorporation assay, and internucleosomal DNA fragmentation assays. The effect of BAY 11-7085 on the cell cycle of ECSCs was also determined by flow cytometry. The expression of apoptosis-related molecules was examined in ECSCs with Western blot analysis. BAY 11-7085 significantly inhibited the cell proliferation and DNA synthesis of ECSCs and induced apoptosis and the G0/G1 phase cell cycle arrest of these cells. Additionally, downregulation of the B-cell lymphoma/leukemia-2 (Bcl-2) and Bcl-X(L) expression with simultaneous activation of caspase-3, -8, and -9 was observed in ECSCs after treatment with BAY 11-7085. These results suggest that BAY 11-7085 induces apoptosis of ECSCs by suppressing antiapoptotic proteins, and that caspase-3-, -8-, and -9-mediated cascades are involved in this mechanism. Therefore, BAY 11-7085 could be used as a therapeutic agent for the treatment of endometriosis.

CBHA is a family of hybrid polar compounds that inhibit histone deacetylase, and induces growth inhibition, cell cycle arrest and apoptosis in human endometrial and ovarian cancer cells.

OBJECTIVES: We investigated the effect of a novel synthesized histone deacetylase inhibitor (HDACI), CBHA, on three endometrial cancer cell lines, two ovarian cancer cell lines, and normal human endometrial epithelial cells. METHODS: Endometrial and ovarian cancer cells were treated with various concentrations of CBHA, and its effect on cell growth, cell cycle, apoptosis, and related measurements was investigated. RESULTS: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay showed that all endometrial and ovarian cancer cell lines were sensitive to the growth-inhibitory effect of CBHA, although normal endometrial epithelial cells were viable after treatment with the same doses of CBHA that induced growth inhibition in endometrial and ovarian cancer cells. Cell cycle analysis indicated that their exposure to CBHA decreased the proportion of cells in the S-phase and increased the proportion in the G(0)/G(1) phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with altered expression of genes related to cell growth, malignant phenotype, and apoptosis. Furthermore, CBHA treatment of these cell lines increased acetylation of H3 and H4 histone tails. CONCLUSIONS: These results raise the possibility that CBHA may prove particularly effective in the treatment of endometrial and ovarian cancers.

Anticancer activity of MS-275, a novel histone deacetylase inhibitor, against human endometrial cancer cells.

BACKGROUND: Histone deacetylase inhibitors (HDACIs) can inhibit cell proliferation, induce cell cycle arrest and stimulate apoptosis of cancer cells. MATERIALS AND METHODS: The effects of a novel HDACI, MS-275, on 4 endometrial cancer cell lines and normal human endometrial epithelial cells was investigated. Endometrial cancer cells were treated with various concentrations of MS-275 and its effect on cell growth, cell cycle, apoptosis and related measurements was investigated. RESULTS: The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays showed that all endometrial cancer cell lines were sensitive to the growth inhibitory effect of MS-275, although the normal endometrial epithelial cells were viable after treatment with the same doses of MS-275 that induced growth inhibition in endometrial cancer cells. The cell cycle analysis indicated that their exposure to MS-275 induced the G0/G1 arrest of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with altered expression of genes related to cell growth, malignant phenotype and apoptosis. CONCLUSION: These results raise the possibility that MS-275 may prove particularly effective in the treatment of endometrial cancer.

A novel histone deacetylase inhibitor, Scriptaid, induces growth inhibition, cell cycle arrest and apoptosis in human endometrial cancer and ovarian cancer cells.

Histone deacetylase inhibitors (HDACIs) can inhibit cell proliferation, induce cell cycle arrest, and stimulate the apoptosis of cancer cells. We investigated the effects of a novel HDACI, Scriptaid, on the Ishikawa endometrial cancer cell line, SK-OV-3 ovarian cancer cell line, and normal human endometrial epithelial cells. Endometrial and ovarian cancer cells were treated with various concentrations of Scriptaid, and its effect on cell growth, cell cycle, apoptosis, and related measurements was investigated. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays showed that all endometrial and ovarian cancer cell lines were sensitive to the growth inhibitory effect of Scriptaid, although normal endometrial epithelial cells were viable after treatment with the same doses of Scriptaid that induced the growth inhibition of endometrial and ovarian cancer cells. Cell cycle analysis indicated that their exposure to Scriptaid decreased the proportion of cells in the S phase and increased the proportion in the G0/G1 and/or G2/M phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with the altered expression of genes related to cell growth, malignant phenotype, and apoptosis. Furthermore, Scriptaid treatment of these cell lines increased acetylation of H3 and H4 histone tails. These results raise the possibility that Scriptaid may prove particularly effective in the treatment of endometrial and ovarian cancers.

Expression of c-Ets1 protein in normal human placenta.

BACKGROUND: The proto-oncogene product c-Ets1 is a transcriptional factor that controls the expression of a number of genes involved in extracellular matrix remodeling such as stromelysin-1 (matrix metalloproteinase-3; MMP-3), collagenase-1, and urokinase-type plasminogen activator (u-PA). To elucidate the involvement of c-Ets1 in the invasive pathway of the trophoblasts, we analyzed c-Ets1 protein expression in placentas by fluorescent immunohistochemistry and Western blot analysis. METHODS: We analyzed serial frozen sections for c-Ets1 protein expression of the chorionic villi and cell column in the first trimester and the basal plate of placenta and amniotic membranes in the third trimester by fluorescent immunohistochemistry. Moreover, we examined the expression of c-Ets1 in the first and the third trimester by Western blot analysis. RESULTS: In the first trimester, c-Ets1 was strongly expressed in the cytoplasm of cytotrophoblasts. Moreover, the cell column that invaded the endometrium had the strongest expression of c-Ets1. In the third trimester, c-Ets1 was detected in both cytoplasm and nucleus of the invading trophoblasts in the basal plate. Furthermore, c-Ets1 was expressed in both cytoplasm and nucleus of the trophoblasts in amniotic membrane. Western blotting revealed that c-Ets1 expressions in the first trimester were stronger than those in the third trimester. CONCLUSION: Our results demonstrate that c-Ets1 expression in normal human placenta correlates to the invasive behavior of the trophoblasts, probably by activating the transcription of matrix-degrading MMPs, including MMP-3, collagenase-1, and u-PA.

M344 is a novel synthesized histone deacetylase inhibitor that induces growth inhibition, cell cycle arrest, and apoptosis in human endometrial cancer and ovarian cancer cells.

OBJECTIVE: Histone deacetylase inhibitors (HDACIs) can inhibit cell proliferation, induce cell cycle arrest, and stimulate apoptosis of cancer cells. METHODS: We investigated the effects of a novel synthesized HDACI, M344, on Ishikawa endometrial cancer cell line, SK-OV-3 ovarian cancer cell line, and normal human endometrial epithelial cells. Endometrial and ovarian cancer cells were treated with various concentrations of M344, and its effect on cell growth, cell cycle, apoptosis, and related measurements was investigated. RESULTS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays showed that all endometrial and ovarian cancer cell lines were sensitive to the growth inhibitory effect of M344, although normal endometrial epithelial cells were viable after the treatment with the same doses of M344 that induced growth inhibition of endometrial and ovarian cancer cells. Cell cycle analysis indicated that their exposure to M344 decreased the proportion of cells in the S-phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with altered expression of genes related to cell growth, malignant phenotype, and apoptosis. Furthermore, M344 treatment of these cell lines increased acetylation of H3 and H4 histone tails. CONCLUSIONS: These results raise the possibility that M344 may prove particularly effective in the treatment of endometrial cancers and ovarian cancers.

C2-ceramide exhibits antiproliferative activity and potently induces apoptosis in endometrial carcinoma.

The purpose of the present study was to investigate the effects of an exogenously administered cell-permeable synthetic ceramide analogue, C(2)-ceramide (N-acetyl-sphingosine) on the growth, cell cycle, and death of Ishikawa human endometrial carcinoma cells. We investigated the effects of C(2)-ceramide on Ishikawa endometrial cancer cell lines in vitro. The cells were treated with C(2)-ceramide, and its effects on cell growth, cell cycle, apoptosis, and related measurements were investigated. MTT assays showed that C(2)-ceramide, a cell-permeable analogue of ceramide, significantly induced dose- and time-dependent death in human endometrial carcinoma Ishikawa cells. Cell-cycle analysis indicated that their exposure to C(2)-ceramide decreased the proportion of cells in S phase and increased the proportion in G0/G1 and/or G2/M phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with the altered expression of genes related to cell growth, malignant phenotype, and apoptosis, including cleavage of poly-ADP ribose polymerase. Furthermore, we demonstrated that the amount of phosphorylated Akt was decreased by C(2)-ceramide. These results raise the possibility that C(2)-ceramide may prove particularly effective in the treatment of endometrial cancers.