BRD4 inhibitor and histone deacetylase inhibitor synergistically inhibit the proliferation of gallbladder cancer in vitro and in vivo

Gallbladder cancer (GBC) is the most common malignancy of the bile duct and has a high mortality rate. Here, we demonstrated that BRD4 inhibitor JQ1 and histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) synergistically inhibited the GBC cells in vitro and in vivo. Our results showed that cotreatment with JQ1 and SAHA significantly inhibited proliferation, cell viability and metastasis, and induced apoptosis and G2/M arrest in GBC cells, with only minor effects in benign cells. In vivo, tumor volumes and weights of GBC xenograft models were significantly decreased after treatment with JQ1 or SAHA; meanwhile, the cotreatment showed the strongest effect. Further study indicated that the above anticancer effects was associated with the downregulation of BRD4 and suppression of PI3K/AKT and MAPK/ERK pathways. These findings highlight JQ1 and SAHA as potential therapeutic agents and their combination as a promising therapeutic strategy for GBC.     

Atiprimod is an inhibitor of cancer cell proliferation and angiogenesis

Atiprimod, a novel compound belonging to the azaspirane class of cationic amphiphilic drugs, exhibits both anti-proliferative and anti-angiogenic activities. Atiprimod inhibited proliferation of all human cancer cell lines included in the National Cancer Institute panel with IC50 values in the low micromolar range. Notably, metastatic cell lines were more sensitive to the compound compared to the non-metastatic cell lines derived from the same tumor tissue types. Atiprimod also induced apoptosis and activated both caspase-9 and caspase-3 in T84 colon carcinoma cells. Hence, the anti-proliferative activity could partly be due to its pro-apoptotic activity. Regarding angiogenesis in vitro, atiprimod inhibited both bFGF and VEGF induced proliferation and migration of human umbilical vein endothelial cells (HUVECs), resulting in disruption of cord formation. In addition, atiprimod also suppressed formation of new blood vessels in a chorioallantoic membrane assay. Previous studies have also shown that atiprimod treatment reduced production of IL-6, VEGF and inhibited activation of Stat3, a constitutively activated protein in majority of human cancers. Together these findings suggest that atiprimod acts on several molecules that are essential for tumor growth, invasion and metastasis.     

Lipoic acid inhibits cell proliferation of tumor cells in vitro and in vivo

Cancer cells convert glucose preferentially to lactate even in the presence of oxygen (aerobic glycolysis–Warburg effect). New concepts in cancer treatment aim at inhibition of aerobic glycolysis. Pyruvate dehydrogenase converts pyruvate to acetylCoA thus preventing lactate formation. Therefore, the aim of this study was to evaluate compounds that could activate pyruvate dehydrogenase in cancer cells. We investigated the effects of (R)-(+)-α-lipoic acid (LPA) and dichloroacetate (DCA), possible activators of pyruvate dehydrogenase, on suppression of aerobic glycolysis and induction of cell death. The neuroblastoma cell lines Kelly, SK-N-SH, Neuro-2a and the breast cancer cell line SkBr3 were incubated with different concentrations (0.1–30 mM) of LPA and DCA. The effects of both compounds on cell viability/proliferation (WST-1 assay), [18F]-FDG uptake, lactate production and induction of apoptosis (flow cytometric detection of caspase-3) were evaluated. Furthermore, NMRI nu/nu mice that had been inoculated s.c. with SkBr3 cells were treated daily for four weeks with LPA (i.p, 18.5 mg/kg) starting at day 7 p.i.. Tumor development was measured with a sliding calliper and monitored via [18F]-FDG-PET. Residual tumors after therapy were examined histopathologically. These data suggests that LPA can reduce (1) cell viability/proliferation, (2) uptake of [18F]-FDG and (3) lactate production and increase apoptosis in all investigated cell lines. In contrast, DCA was almost ineffective. In the mouse xenograft model with s.c. SkBr3 cells, daily treatment with LPA retarded tumor progression. Therefore, LPA seems to be a promising compound for cancer treatment.     

Ipatasertib,an oral AKT inhibitor,inhibits cell proliferation and migration,and induces apoptosis in serous endometrial cancer

Ipatasertib (IPAT) is an orally administered, selective protein kinase B (AKT) inhibitor with promising data in solid tumors in both pre-clinical studies and clinical trials. Given that the PI3K/AKT/mTOR pathway is frequently dysregulated in uterine serous carcinoma (USC), we aimed to explore the functional impact of IPAT on anti-tumorigenic activity in USC cell lines and primary cultures of USC. We found that IPAT significantly inhibited cell proliferation and colony formation in a dose-dependent manner in USC cells. Induction of cell cycle arrest and apoptosis was observed in IPAT-treated ARK1 and SPEC-2 cells. Treatment with IPAT resulted in reduced adhesion and invasion of both cell lines with a concomitant decrease in the expression of Snail, Slug, and N-Cadherin. Compared with single-drug treatment, the combination of IPAT and paclitaxel synergistically reduced cell proliferation and increased the activity of cleaved caspase 3 in both cell lines. Additionally, IPAT inhibited growth in four of five primary USC cultures, and three of five primary cultures also exhibited synergistic growth inhibition when paclitaxel and IPAT were combined. These results support that IPAT appears to be a promising targeted agent in the treatment of USC.     

Drug-induced senescence bystander proliferation in prostate cancer cells in vitro and in vivo

Senescence is a distinct cellular response induced by DNA-damaging agents and other sublethal stressors and may provide novel benefits in cancer therapy. However, in an ageing model, senescent fibroblasts were found to stimulate the proliferation of cocultured cells. To address whether senescence induction in cancer cells using chemotherapy induces similar effects, we used GFP-labelled prostate cancer cell lines and monitored their proliferation in the presence of proliferating or doxorubicin-induced senescent cancer cells in vitro and in vivo. Here, we show that the presence of senescent cancer cells increased the proliferation of cocultured cells in vitro through paracrine signalling factors, but this proliferative effect was significantly less than that seen with senescent fibroblasts. In vivo, senescent cancer cells failed to increase the establishment, growth or proliferation of LNCaP and DU145 xenografts in nude mice. Senescent cells persisted as long as 5 weeks in tumours. Our results demonstrate that although drug-induced senescent cancer cells stimulate the proliferation of bystander cells in vitro, this does not significantly alter the growth of tumours in vivo. Coupled with clinical observations, these data suggest that the proliferative bystander effects of senescent cancer cells are negligible and support the further development of senescence induction as therapy.     

DNA甲基转移酶抑制剂对结肠癌细胞增殖、凋亡及细胞周期影响的体外研究

目的 探讨DNA甲基转移酶抑制剂SGI-1027对结肠癌LoVo细胞增殖、凋亡及细胞周期的影响。方法 取对数生长期LoVo细胞,实验组加入终浓度分别为0.1、1、5、10 μmol／L SGI-1027的培养液,对照组用含10％胎牛血清的RPMI 1640 培养基同步培养。MTT法检测SGI-1027作用于LoVo细胞24、48、72 h的增殖抑制率;倒置相差显微镜观察细胞形态学变化;SGI-1027处理后每个浓度收集细胞1×106个,采用膜联蛋白V-异硫氰酸荧光素（Annexin V-FITC）／碘化丙啶（PI）双染或PI单染流式细胞术分别检测SGI-1027处理后的细胞凋亡率和细胞周期时相分布情况;Western blotting检测SGI-1027对PI3K／Akt通路的影响。 结果 倒置相差显微镜观察显示,随SGI-1027浓度和作用时间的增加,LoVo细胞的凋亡形态学改变更为显著。除0.1 μmol／L SGI-1027处理24 h后的LoVo细胞增殖抑制率与对照组无差异外,随着药物浓度的增加和作用时间的延长,SGI-1027对LoVo细胞的增殖抑制作用不断增强。与对照组比较,SGI-1027（0.1～10 μmol／L）处理LoVo细胞24、48 h的凋亡率均升高,且各浓度间的差异均有统计学意义（P＜0.05）。与对照组比较,1～10 μmol／L SGI-1027处理后G0／G1期细胞比例及PTEN水平均高于对照组,S期和G2／M期细胞比例及Akt水平均低于对照组,差异有统计学意义（P＜0.05）。结论 SGI-1027可抑制LoVo细胞的增殖并诱导细胞凋亡及G0／G1期阻滞,可能与其抑制PI3K／Akt通路激活有关,且SGI-1027作用的时间和浓度均对LoVo 细胞恶性行为有影响。     

靶向XIAP的siRNA抑制结肠癌LoVo细胞体内外的增殖

目的：研究siRNA干扰X连锁凋亡抑制蛋白（Xlinked inhibitor of apoptosis protein, XIAP）基因表达对结肠癌细胞LoVo体内外增殖的影响。方法：构建XIAP真核表达干扰载体pSil2.1shXIAP1和pSil2.1shXIAP2,脂质体转染结肠癌细胞株LoVo,G418筛选出稳定转染LoVoshXIAP2细胞。RTPCR和Western blotting方法检测XIAP mRNA和蛋白的表达。MTT法和平板克隆形成实验检测LoVo细胞的增殖;流式细胞仪检测细胞的凋亡;裸鼠移植瘤模型观察XIAP表达下调对结肠癌体内增殖活性的影响。结果：LoVoshXIAP2细胞中XIAP mRNA和蛋白表达水平均显著下调。相对于对照组细胞,LoVoshXIAP2细胞的增殖和克隆形成率显著降低(P<0.01）,凋亡率显著增加（P<0.01）。 LoVoshXIAP2移植瘤组织中XIAP蛋白表达明显下调,LoVoshXIAP2移植瘤生长显著抑制（均P<0.05）。结论：pSil2.1shXIAP2能够抑制结肠癌LoVo细胞中XIAP蛋白的表达,抑制LoVo细胞体内外的增殖,有望成为结肠癌免疫治疗的新手段。     

S-allylmercaptocysteine effectively inhibits the proliferation of colorectal cancer cells under in vitro and in vivo conditions

S-allylmercaptocysteine (SAMC), one of the water-soluble organosulfur garlic derivatives, has been demonstrated as a suppressive agent against some tumors. The effects of SAMC on the proliferation and metastasis of colorectal cancer (CRC) under in vitro and in vivo conditions were evaluated here. The viabilities and migrations of CRC cells SW480, SW620, Caco-2 treated with SAMC were measured by MTT, scratch-wound, and transwell assays. The in vivo anticancer effect of SAMC against luciferase-expressing SW620 xenografts in mice was determined by bioluminescence imaging and histopathology observation. The apoptosis of SAMC-treated CRC cells was examined by Western blotting. The results demonstrate that SAMC could effectively suppress the growth and metastasis of colorectal cancer cells both in vivo and in vitro. The anticancer effect of SAMC was related to the decreased proliferation and increased apoptosis as well as necrosis of cancer cells. Oral administration of SAMC in the quantity/concentration used had no apparent toxic side effect on the vital organs of the experimental mice. Taken together, the proliferation and metastasis of CRC cells can be significantly suppressed by SAMC treatment under both in vitro and in vivo conditions. SAMC may thus be a promising candidate for CRC chemotherapy.     

Gonadotropin-releasing hormone type II antagonists induce apoptotic cell death in human endometrial and ovarian cancer cells in vitro and in vivo

In human endometrial and ovarian cancers, gonadotropin-releasing hormone type I (GnRH-I), GnRH-II, and their receptors are parts of a negative autocrine regulatory system of cell proliferation. Based on a tumor-specific signal transduction, GnRH-I and GnRH-II agonists inhibit the mitogenic signal transduction of growth factor receptors and related oncogene products associated with tyrosine kinase activity via activation of a phosphotyrosine phosphatase resulting in down-regulation of cancer cell proliferation. Induction of apoptosis is not involved. In this study, we show that treatment of human endometrial and ovarian cancer cells with GnRH-II antagonists results in apoptotic cell death via dose-dependent activation of caspase-3. The antitumor effects of the GnRH-II antagonists could be confirmed in nude mice. GnRH-II antagonists inhibited the growth of xenotransplants of human endometrial and ovarian cancers in nude mice significantly, without any apparent side effects. Thus, GnRH-II antagonists seem to be suitable drugs for an efficacious and less toxic endocrine therapy for endometrial and ovarian cancers.     

Green tea polyphenols and its constituent epigallocatechin gallate inhibits proliferation of human breast cancer cells in vitro and in vivo

Tea [Camellia sinensis (Theaceae)] intake is second only to water in terms of worldwide popularity as a beverage. The Green tea polyphenols have been shown to have a protective effect in prostate cancer in various pre-clinical animal models and has been reported to be effective in several other cancer types as well. An inverse association between the risk of breast cancer and the intake of green tea has also been reported in Asian Americans. Several epidemiological studies have shown that breast cancer progression is delayed in the Asian population that consumes green tea on regular basis. In this study, we report the effectiveness of green tea polyphenols (GTP) and its constituent Epigallocatechin Gallate (EGCG) in tumor regression using both in-vitro cell culture models and in vivo athymic nude mice models of breast cancer. The anti-proliferative effect of GTP and EGCG on the growth of human breast cancer MDA-MB-231 cell was studied using a tetrazolium dye-based (MTT) assay. Both GTP and EGCG treatment had the ability to arrest the cell cycle at G1 phase as assessed by flow cytometry. The expression of Cyclin D, Cyclin E, CDK 4, CDK 1 and PCNA were down regulated over the time in GTP and EGCG treated experimental group, compared to the untreated control group as evaluated by western blot analysis for cell cycle proteins, which corroborated the G1 block. Nude mice inoculated with human breast cancer MDA-MB-231 cells and treated with GTP and EGCG were effective in delaying the tumor incidence as well as reducing the tumor burden when compared to the water fed and similarly handled control. GTP and EGCG treatment were also found to induce apoptosis and inhibit the proliferation when the tumor tissue sections were examined by immunohistochemistry. Our results suggest that GTP and EGCG treatment inhibits proliferation and induce apoptosis of MDA-MB-231 cells in-vitro and in-vivo. All together, these data sustain our contention that GTP and EGCG have anti-tumor properties.     

In vitro and in vivo growth inhibition of human malignant astrocytoma cells by the farnesyltransferase inhibitor B1620

p21-Ras, the protein product of the proto-oncogene Ras is overactivated in malignant astrocytomas despite the absence of mutation. It is known that p21-Ras participates in signaling events from membrane tyrosine kinase receptors and a variety of intracellular biochemical pathways to downstream targets. Signal transduction inhibition by targeting against Ras is now thought to be a promising therapeutic strategy for malignant astrocytomas. This study demonstrates that Ras pathway inactivation by a farnesyltransferase inhibitor, B1620, effectively inhibits in vitro and in vivo growth of human astrocytoma cells, although normal human astrocytes (NHA) derived from fetal brain are resistant to B1620. Anti-proliferative effect of B1620 on in vitro growth of astrocytoma cells was examined by MTT assays and soft agar colony formation assay. B1620 inhibited anchorage-dependent growth of six astrocytoma cell lines with a median effective dose (IC₅₀) ranging from 2.0 to 20.7µM. However, growth of NHA was not significantly affected by B1620 even at the concentration of 100µM. All astrocytoma cells showed apoptotic figures after Hoechst 33258 staining, when treated for 5 days at each IC₅₀ concentration against B1620. Anchorage-independent growth of these astrocytoma cell lines was inhibited at a much lower concentration than that of anchorage-dependent growth. Daily treatment of U87 xenograft-bearing athymic mice with B1620 at 100 or 50mgkg^–1 resulted in significant inhibition of tumor growth. A histological study of the B1620-treated tumor tissue showed decreased vascularity with numerous TUNEL-positive apoptotic cells. These results suggest that the mechanism of the growth-inhibitory effect of B1620 is anti-angiogenesis, apoptosis induction and reversion of the transformed phenotype. The potential clinical use of B1620 could be expanded to malignant astrocytomas.     

Cholesterol content and malignant proliferation of cancer cells

The relationship between cholesterol content and proliferation of cancer cells was studied. When the cholesterol content of cancer cells increased. cAMP content of the cells also increased; the agglutinability of the cells decreased; the percentage of diploid cells increased greatly (from 54% to 79%) and the tetraploid cells reduced rapidly (from 43% to 15%). It was shown that the malignant proliferation of cancer cells decreased obviously. The cholesterol was not absorbed markedly by the V79 cell line and embryo lung cells as compared with the cancer cells when cholesterol content in the medium was increased. There were no apparent changes in the percentages of diploid cells or tetraploid cells.     

miR-96在子宫内膜癌中表达的变化及其对癌细胞恶性生物学行为的影响

目的:探讨miR-96在子宫内膜癌组织和细胞中表达的变化对瘤细胞恶性表型的影响及其可能的作用机制.方法:选取2016年4月至2018年12月在我院妇产科接受手术治疗的76例子宫内膜癌患者的癌组织标本,采用实时荧光定量PCR(qPCR)检测人子宫内膜癌组织和细胞中miR-96的表达情况,并分析miR-96的表达与患者临床...     

Defining the role of prolactin as an invasion suppressor hormone in breast cancer cells

Prolactin hormone (PRL) is well characterized as a terminal differentiation factor for mammary epithelial cells and as an autocrine growth/survival factor in breast cancer cells. However, this function of PRL may not fully signify its role in breast tumorigenesis. Cancer is a complex multistep progressive disease resulting not only from defects in cell growth but also in cell differentiation. Indeed, dedifferentiation of tumor cells is now recognized as a crucial event in invasion and metastasis. PRL plays a critical role in inducing/maintaining differentiation of mammary epithelial cells, suggesting that PRL signaling could serve to inhibit tumor progression. We show here that in breast cancer cells, PRL and Janus-activated kinase 2, a major kinase involved in PRL signaling, play a critical role in regulating epithelial-mesenchymal transformation (EMT), an essential process associated with tumor metastasis. Activation of the PRL receptor (PRLR), achieved by restoring PRL/JAK2 signaling in mesenchymal-like breast cancer cells, MDA-MB-231, suppressed their mesenchymal properties and reduced their invasive behavior. While blocking PRL autocrine function in epithelial-like breast cancer cells, T47D, using pharmacologic and genetic approaches induced mesenchymal-like phenotypic changes and enhanced their invasive propensity. Moreover, our results indicate that blocking PRL signaling led to activation of mitogen-activated protein kinase (extracellular signal-regulated kinase 1/2) and transforming growth factor-beta/Smad signaling pathways, two major prometastatic pathways. Furthermore, our results indicate that following PRL/JAK2 inhibition, ERK1/2 activation precedes and is required for Smad2 activation and EMT induction in breast cancer cells. Together, these results highlight PRL as a critical regulator of epithelial plasticity and implicate PRL as an invasion suppressor hormone in breast cancer.     

Targeting mTORC2 inhibits colon cancer cell proliferation in vitro and tumor formation in vivo

The mammalian target of rapamycin (mTOR), which exists in two functionally distinct complexes, mTORC1 and mTORC2 plays an important role in tumor growth. Whereas the role of mTORC1 has been well characterized in this process, little is known about the functions of mTORC2 in cancer progression. In this study, we explored the specific role of mTORC2 in colon cancer using a short hairpin RNA expression system to silence the mTORC2-associated protein rictor. We found that downregulation of rictor in HT29 and LS174T colon cancer cells significantly reduced cell proliferation. Knockdown of rictor also resulted in a G1 arrest as observed by cell cycle analysis. We further observed that LS174T cells deficient for rictor failed to form tumors in a nude mice xenograft model. Taken together, these results show that the inhibition of mTORC2 reduces colon cancer cell proliferation in vitro and tumor xenograft formation in vivo. They also suggest that specifically targeting mTORC2 may provide a novel treatment strategy for colorectal cancer.     

Suberoylanilide hydroxamic acid, an inhibitor of histone deacetylase, suppresses the growth of prostate cancer cells in vitro and in vivo

Suberoylanilide hydroxamic acid (SAHA) is the prototype of a family of hybrid polar compounds that induce growth arrest in transformed cells and show promise for the treatment of cancer. SAHA induces differentiation and/or apoptosis in certain transformed cells in culture and is a potent inhibitor of histone deacetylases. In this study, we examined the effects of SAHA on the growth of human prostate cancer cells in culture and on the growth of the CWR22 human prostate xenograft in nude mice. SAHA suppressed the growth of the LNCaP, PC-3, and TSU-Pr1 cell lines at micromolar concentrations (2.5-7.5 microM). SAHA induced dose-dependent cell death in the LNCaP cells. In mice with transplanted CWR222 human prostate tumors, SAHA (25, 50, and 100 mg/kg/day) caused significant suppression of tumor growth compared with mice receiving vehicle alone; treatment with 50 mg/kg/day resulted in a 97% reduction in the mean final tumor volume compared with controls. At this dose, there was no detectable toxicity as evaluated by weight gain and necropsy examination. Increased accumulation of acetylated core histones was detected in the CWR22 tumors within 6 h of SAHA administration. SAHA induced prostate-specific antigen mRNA expression in CWR22 prostate cancer cells, resulting in higher levels of serum prostate-specific antigen than predicted from tumor volume alone. The results suggest that hydroxamic acid-based hybrid polar compounds inhibit prostate cancer cell growth and may be useful, relatively nontoxic agents for the treatment of prostate carcinoma.     

三氧化二砷抑制子宫内膜癌生长的体内外实验研究

目的:探讨三氧化二砷(arsenic trioxide, ATO)对人子宫内膜癌HEC-1-A细胞生长的抑制作用.方法:采用MTT法比较ATO、孕酮、安宫黄体酮(medroxyprogesterone acetate,MPA)和顺铂(cisplatin, CDDP)对HEC-1-A细胞的抑制作用,应用FCM和DNA电泳检测ATO对细胞周期和细胞凋亡的影响.建立裸鼠人子宫内膜癌移植瘤动物模型,随机分为ATO低(4 mg·kg-1·d-1)、中(6 mg·kg-1·d-1)、高(8 mg·kg-1·d-1)剂量组、阳性对照CDDP组(3 mg·kg-1·d-1)及阴性对照组,腹腔连续给药14 d,计算肿瘤体积和肿瘤质量抑制率.结果:1～20 μmol/L ATO和CDDP可明显抑制细胞生长,且ATO 对细胞的抑制作用强于CDDP.5 μmol/L ATO作用后可导致细胞凋亡,并使细胞周期阻滞于S和G2/M期.低、中、高剂量ATO组和CDDP组的肿瘤体积抑制率分别为50.97%、75.58%、56.92%和52.23%,肿瘤质量抑制率分别为10.15%、29.33%、16.67%和14.69%,与阴性对照组相比差异有统计学意义(P＜0.05).结论:ATO可抑制HEC-1-A细胞及鼠荷人子宫内膜癌移植瘤的生长,有望成为治疗子宫内膜癌的新型药物.