• Biomolecules & Therapeutics
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• v.29 no.6
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• pp.650-657
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• 2021

Metformin is an anti-diabetic drug and has anticancer effects on various cancers. Several studies have suggested that metformin reduces cell proliferation and stimulates cell-cycle arrest and apoptosis. However, the definitive molecular mechanism of metformin in the pathophysiological signaling in endometrial tumorigenesis and metastasis is not clearly understood. In this study, we examined the effects of metformin on the cell viability and apoptosis of human cervical HeLa and endometrial HEC-1-A and KLE cancer cells. Metformin suppressed cell growth in a dose-dependent manner and dramatically evoked apoptosis in HeLa cervical cancer cells, while apoptotic cell death and growth inhibition were not observed in endometrial (HEC-1-A, KLE) cell lines. Accordingly, the p27 and p21 promoter activities were enhanced while Bcl-2 and IL-6 activities were significantly reduced by metformin treatment. Metformin diminished the phosphorylation of mTOR, p70S6K and 4E-BP1 by accelerating adenosine monophosphate-activated kinase (AMPK) in HeLa cancer cells, but it did not affect other cell lines. To determine why the anti-proliferative effects are observed only in HeLa cells, we examined the expression level of liver kinase B1 (LKB1) since metformin and LKB1 share the same signalling system, and we found that the LKB1 gene is not expressed only in HeLa cancer cells. Consistently, the overexpression of LKB1 in HeLa cancer cells prevented metformin-triggered apoptosis while LKB1 knockdown significantly increased apoptosis in HEC-1-A and KLE cancer cells. Taken together, these findings indicate an underlying biological/physiological molecular function specifically for metformin-triggered apoptosis dependent on the presence of the LKB1 gene in tumorigenesis.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3653-3656
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• 2012

Background: A number of effective prevention measures have been introduced in attempts to substantially reduce both the incidence and mortality due to many kinds of cancer. The search for new anti-cancer compounds in foods or in plant medicines is one realistic and promising approach to prevention. Chinese medicines provide a rich pool of novel and efficacious agents for cancer prevention and treatment. Previously it was demonstratrated that hyperin extracted from the Manchurian rhododendron leaf reduces the proliferation of many cancer cells. The present study was carried out to evaluate its effects on human endometrial cancer cell viability and apoptosis and to investigate its mechanisms of action in RL952 cells. Methods: Cell viability was measured using the MTT assay. Intracellular calcium ions were detected using laser-scanning confocal microscopy. The effects of hyperin on apoptosis related proteins in RL952 cells were examined using Western blot analysis. Results: The growth of RL952 cells was inhibited by treatment with hyperin. OD values of caspase-3 and caspase-9 were increased and expression of bcl-2 was increased and bax was decreased in protein levels in RL952 cells after 24 h of hyperin treatment, Moreover, intracellular calcium accumulation occurred in hyperin-treated cells. Conclusion: These results suggest that hyperin may play an important role in tumor growth suppression by inducing apoptosis in human endometrial cells via a $Ca^{2+}$-related mitochondrion apoptotic pathway in RL952 cells.

• Journal of Ginseng Research
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• v.46 no.4
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• pp.592-600
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• 2022

Background: Di-(2-ethylhexyl) phthalate (DEHP) is the most common endocrine disrupting chemical used as a plasticizer. DEHP is associated with the development of endometrium-related diseases through the induction of inflammation. The major therapeutic approaches against endometrial cancer and endometriosis involve the suppression of inflammatory response. Korean Red Ginseng (KRG) is a natural product with anti-inflammatory and anti-carcinogenic properties. Thus, the purpose of this study is to investigate the effects of KRG on DEHP-induced inflammatory response in endometrial cancer Ishikawa cells and a mouse model of endometriosis. Methods: RNA-sequencing was performed and analyzed on DEHP-treated Ishikawa cells in the presence and absence of KRG. The effects of KRG on DEHP-induced cyclooxygenase-2 (COX-2) mRNA levels in Ishikawa cells were determined by RT-qPCR. Furthermore, the effects of KRG on the extracellular signal-regulated kinases (ERKs) pathway, COX-2, and nuclear factor-kappa B (NF-kB) p65 after DEHP treatment of Ishikawa cells were evaluated by western blotting. In the mouse model, the severity of endometriosis induced by DEHP and changes in immunohistochemistry were used to assess the protective effect of KRG. Results: According to the RNA-sequencing data, DEHP-induced inflammatory response-related gene expression was downregulated by KRG. Moreover, KRG significantly inhibited DEHP-induced ERK1/2/NF-κB/COX-2 levels in Ishikawa cells. In the mouse model, KRG administration significantly inhibited ectopic endometriosis growth after DEHP-induced endometriosis. Conclusions: Overall, these results suggest that KRG may be a promising lead for the treatment of endometrial cancer and endometriosis via suppression of the inflammatory response.

• Journal of Ginseng Research
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• v.44 no.1
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• pp.96-104
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• 2020

Objectives: Oleanolic acid, a minor element of ginsenosides, and its derivatives have been shown to have cytotoxicity against some tumor cells. The impact of cytotoxic effect of oleanolic acid 3-acetate on ovarian cancer SKOV3 cells and endometrial cancer HEC-1A cells were examined both in vivo and in vitro to explore the underlying mechanisms. Methods: Cytotoxic effects of oleanolic acid 3-acetate were assessed by cell viability, phosphatidylserine exposure on the cell surface, mitochondrial release of cytochrome C, nuclear translocation of apoptosis-inducing factor, depolarization of mitochondrial transmembrane potential (∆Ψ_m), and generation of reactive oxygen species (ROS). In vivo inhibition of tumor growth was also assessed with xenografts in immunocompromised mice. Results: Oleanolic acid 3-acetate exhibited potent cytotoxicity toward SKOV3 and HEC-1A cells by decreasing cell viability in a concentration-dependent manner. Importantly, oleanolic acid 3-acetate effectively suppressed the growth of SKOV3 cell tumor xenografts in immunocompromised mice. Furthermore, oleanolic acid 3-acetate induced apoptotic cell death as revealed by loss of ∆Ψ_m, release of cytochrome c, and nuclear translocation of apoptosis-inducing factor with a concomitant activation of many proapoptotic cellular components including poly(ADP-ribose) polymerase, Bcl-2, and caspases-8, caspase-3, and caspase-7. Oleanolic acid 3-acetate, however, caused a decrease in ROS production, suggesting the involvement of an ROS-independent pathway in oleanolic acid 3-acetate-induced apoptosis in SKOV3 and HEC-1A cells. Conclusion: These findings support the notion that oleanolic acid 3-acetate could be used as a potent anticancer supplementary agent against ovarian and endometrial cancer. Oleanolic acid 3-acetate exerts its proapoptotic effects through a rather unique molecular mechanism that involves an unconventional ROS-independent but mitochondria-mediated pathway.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.126-133
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• 2021

Background: 20(S)-protopanaxadiol (20(S)-PPD), one of the aglycone derivatives of major ginsenosides, has been shown to have an anticancer activity toward a variety of cancers. This study was initiated with an attempt to evaluate its anti-cancer activity toward human endometrial cancer by cell and xenograft mouse models. Methods: Human endometrial cancer (HEC)-1A cells were incubated with different 20(S)-PPD concentrations. 20(S)-PPD cytotoxicity was evaluated using MTT assay. Apoptosis was detected using the annexin V binding assay and cell cycle analysis. Cleaved poly (ADP-ribose) polymerase (PARP) and activated caspase-9 were assessed using western blotting. HEC-1A cell tumor xenografts in athymic mice were generated by inoculating HEC-1A cells into the flank of BALB/c female mice and explored to validate 20(S)-PPD anti-endometrial cancer toxicity. Results: 20(S)-PPD inhibited HEC-1A cell proliferation in a dose-dependent manner with an IC50 value of 3.5 μM at 24 h. HEC-1A cells morphologically changed after 20(S)-PPD treatment, bearing resemblance to Taxol-treated cells. Annexin V-positive cell percentages were 0%, 10.8%, and 58.1% in HEC-1A cells when treated with 0, 2.5, and 5 μM of 20(S)-PPD, respectively, for 24 h. 20(S)-PPD subcutaneously injected into the HEC-1A cell xenograft-bearing mice three times a week for 17 days manifested tumor growth inhibition by as much as 18% at a dose of 80 mg/kg, which sharply contrasted to controls that showed an approximately 2.4-fold tumor volume increase. These events paralleled caspase-9 activation and PARP cleavage. Conclusion: 20(S)-PPD inhibits endometrial cancer cell proliferation by inducing cell death via a caspase-mediated apoptosis pathway. Therefore, the 20(S)-PPD-like ginsenosides are endowed with ample structural information that could be utilized to develop other ginsenoside-based anticancer agents.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.195-198
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• 2014

Aim: To evaluate precancerous lesions such as hyperplasia and endometrial polyps in obese postmenopausal women. Materials and Methods: Women who were referred with abnormal uterine bleeding in postmenopausal period or the presence of endometrial cells on cervical cytology in our department were investigated. Anthropometric measurements such as height, weight, body mass index, waist/hip ratio and endometrial thickness were compared between a precancerous lesion (hyperplasia and endometrial polyp) group and a pathologically normal group. Results: We detected statistically significant thickening of endometrium in patients with precancerous lesions. Moreover patients with precancerous lesions had higher body mass index than the pathologically normal group. Conclusions: We found elevated precancerous lesion rates in overweight and obese women in the postmenopausal period, of interest given that the prevalence of obesity is increasing in most parts of the world. Although screening for endometrial cancer is not recommended for the general population, in high-risk populations like obese postmenopausal women, it may be very important.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.8975-8979
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• 2014

Objective: To explore the possible significance of aromatase P450 in endometrial hyperplasia with a background of polycystic ovary syndrome (PCOS). Methods: Immunohistochemistry was used to determine the expression of aromatase P450 in endometrium of PCOS patients. Semiquantitative analysis of aromatase P450 expression of mRNA and protein level wasalso carried out by real-time quantitative RT-PCR method. After endometrial cells were stimulated by testosterone and letrozole in vitro, the estradiol ($E_2$) level was determined, and the expression of cell aromatase P450 mRNA was assessed. Results: The aromatase P450 mRNA level was increased in endometria of PCOS patients. When endometrial cells were cultured with $10^{-6}M$ testosterone, the $E_2$ level in the culture medium increased. An inhibitory effect on $E_2$ generation and expression of aromatase P450 mRNA was observed when the endometrial cells were treated with $10^{-5}M$ letrozole. Conclusions: There is an increased expression of aromatase P450 in PCOS patient endometrium. Androgen stimulation could enhance the synthesis of aromatase P450 mRNA and the production of $E_2$ in endometrial cells in vitro while letrozole could do the reverse.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1689-1692
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• 2014

Background: An easy, reproducible and simple marker is needed to estimate phase of endometrial pathologic lesions such as hyperplasia and endometrial cancer and distinguish from pathologically normal results. We here aimed to clarify associations among neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), endometrial hyperplasia and cancer in patients with abnormal uterine bleeding. Materials and Methods: Patients (n=161) who were admitted with abnormal uterine bleeding and the presence of endometrial cells on cervical cytology or thick endometrium were investigated. The study constituted of three groups according to pathologic diagnosis. Group 1 included endometrial precancerous lesions like hyperplasia (n=63), group 2 included endometrial cancerous lesions (n=38) and group 3 was a pathologically normal group (n=60). Blood samples were obtained just before the curettage procedure and the NLR was defined as the absolute neutrophil count divided by the absolute lymphocyte count; similarly, PLR was defined as the absolute platelet count divided by the absolute lymphocyte count. Results: The white blood cell count was significantly higher in patients with cancer than in those with hyperplasia (p=0.005). The platelet count and neutrophil to lymphocyte ratio were significantly higher in patients with cancer than in control patients, but there was significantly no difference between patients with hyperplasia and other groups (p=0.001 and p=0.025 respectively). PLR was significantly lower in control subjects than in other groups (p<0.001), but there was no significant difference between patients with hyperplasia and those with cancer. Conclusions: PLR was significantly lower in control subjects than in other groups. Thus both hyperplasia and cancer may be differentiated from pathologically normal patients by using PLR. White blood cell count was significantly higher in patients with cancer than in those with hyperplasia and pathologically normal patients. Therefore white blood cell count may be used for discriminate hyperplasia to cancer. By using multiple inflammation parameters, discrimination may be possible among endometrial cancer, endometrial precancerous lesions and pathologically normal patients.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.11
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• pp.4571-4576
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• 2015

Background: To investigate the inhibitory effect and the underlying mechanism of triptolide on cultured human endometrial carcinoma HEC-1B cells and corresponding xenograft. Materials and Methods: For in vitro studies, the inhibition effect of proliferation on HEC-1B cell by triptolide was determined by MTT assay; cell cycle and apoptosis of the triptolide-treated and untreated cells were detected by flow cytometry. For in vivo studies, a xenograft tumor model of human endometrial carcinoma was established using HEC-1B cells, then the tumor-bearing mice were treated with high, medium, and low-dose ($8{\mu}g$, $4{\mu}g$ and $2{\mu}g/day$) triptolide or cisplatin at $40{\mu}g/day$ or normal saline as control. The mice were treated for 10-15 days, during which body weight of the mice and volume of the xenograft were weighted. Then expression of Bcl-2 and vascular endothelial growth factor (VEGF) was analyzed by SABC immunohistochemistry. Results: Cell growth was significantly inhibited by triptolide as observed by an inverted phase contrast microscope; the results of MTT assay indicated that triptolide inhibits HEC-1B cell proliferation in a dose and time-dependent manner; flow cytometry showed that low concentration (5 ng/ml) of triptolide induces cell cycle arrest of HEC-1B cells mainly at S phase, while higher concentration (40 or 80 ng/ml) induced cell cycle arrest of HEC-1B cells mainly at G2/M phase, and apoptosis of the cells was also induced. High-dose triptolide showed a similar tumor-inhibitory effect as cisplatin (-50%); high-dose triptolide significantly inhibited Bcl-2 and VEGF expression in the xenograft model compared to normal saline control (P<0.05). Conclusions: triptolide inhibits HEC-1B cell growth both in vitro and in mouse xenograft model. Cell cycle of the tumor cells was arrested at S and G2/M phase, and the mechanism may involve induction of tumor cell apoptosis and inhibition of tumor angiogenesis.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.221-225
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• 2015

As metformin can inhibit endometrial carcinoma (EC) cell growth and the insulin growth factor (IGF) system is active in EC, the question of whether it can regulate endometrial carcinoma cell secretion of IGF-1 or expression of IGF-1 receptor (IGF-1R) is of interest. In this study, serum IGF-1 levels in EC patients were found to be comparable with that in the non EC patients (p>0.05). However, the IGF-1 level in the medium of cultured cells after treatment with metformin was decreased (p<0.05). IGF-1R was highly expressed in human endometrial carcinoma paraffin sections, but IGF-1R and phosphor-protein kinase B/protein kinase B (p-Akt/Akt) expression was down-regulated after metformin treatment (p<0.05). In summary, metformin can reduce the secretion of IGF-1 by Ishikawa and JEC EC cell lines and their expression of IGF-1R to deactivate downstream signaling involving the PI-3K/Akt pathway to inhibit endometrial carcinoma cell growth.