Growth inhibition of colon cancer cells by compounds affecting AMPK activity

AIM: To determine if other molecules reported to modulate AMP-dependent protein kinase (AMPK) activity would have effects resembling those of metformin and phenformin on colon cancer cell proliferation and metabolism. METHODS: Studies were performed with four human colon cancer cell lines, Caco-2, HCT116, HT29 and SW1116. The compounds that were studied included A-769662, 5-aminoimidazole-4-carboxamide-1-ribofuranoside, butyrate, (-)-epigallocatechin gallate (EGCG), KU-55933, quercetin, resveratrol and salicylates. The parameters that were measured were cell proliferation and viability, glucose uptake, lactate production and acidification of the incubation medium. RESULTS: Investigations with several molecules that have been reported to be associated with AMPK activation (A-769662, 5-aminoimidazole-4-carboxamide-1-b-D-ribofuranoside, EGCG, KU-55933, quercetin, resveratrol and salicylates) or AMPK inhibition (compound C) failed to reveal increased medium acidification and increased glucose uptake in colon cancer cells as previously established with metformin and phenformin. The only exception was 5-aminosalicylic acid with which there were apparently lower glucose levels in the medium after incubation for 72 h. Further study in the absence of cells revealed that the effect was an artifact due to inhibition of the enzyme-linked glucose assay. The compounds were studied at concentrations that inhibited cell proliferation. CONCLUSION: It was concluded that treatment with several agents that can affect AMPK activity resulted in the inhibition of the proliferation of colon cancer cells under conditions in which glucose metabolism is not enhanced, in contrast to the effect of biguanides.     

Ursodeoxycholic acid differentially affects three types of sphingomyelinase in human colon cancer Caco 2 cells

We investigated the effects of UDCA on sphingomyelinase (SMase) in Caco 2 cells cultured in monolayer and polarized conditions. Alkaline SMase activity was high in polarized cells whereas, acid and neutral SMase activities were high in monolayer cells. In polarized cells, UDCA increased alkaline SMase expression and caspase 3 activity but had no effect on acid and neutral SMases. In monolayer cells, UDCA reduced both acid and neutral SMase activities, inhibited cell proliferation, but had little effect on alkaline SMase and caspase 3 activities. In conclusion, UDCA differentially affects SMase activity, cell proliferation, and apoptosis in colonic cells depending on the cell conditions.     

CCR7活化与人结肠癌SW620细胞的体外增殖、趋化与侵袭的关系

目的研究CCR7活化对结肠癌SW620细胞体外增殖、趋化与侵袭活性的影响。方法MTT法和软琼脂细胞集落培养观察CCR7活化对细胞增殖的影响,Boyden小室法检测CCR7活化对SW620细胞趋化和侵袭活性的影响。结果和对照组相比CCL21组细胞增殖数量、软琼脂细胞集落数和穿过Boyden小室膜的细胞数均显著增加（P〈0．01）。结论CCR7活化能够促进结肠癌SW620细胞的体外增殖、趋化与侵袭,其可能参与了结肠癌淋巴结转移的过程。进一步研究CCR7在结肠癌中的作用将有助于阐明结肠癌淋巴结转移的机制。     

TRPM8激活Calcineurin-NFATc3通路调节结肠癌细胞免疫逃逸

目的  探讨TRPM8调节结肠癌细胞免疫逃逸的机制。方法 采用qRT-PCR和Western blot检测结肠癌细胞系SW620和正常人结肠上皮细胞系CCD 841 CoN中TRPM8的表达水平。将干涉和过表达TRPM8载体TRPM8 siRNA和pcDNA3.1-TRPM8转染至SW620细胞，并设置相应对照组（Control siRNA组和pcDNA3.1组），用CCK-8、集落形成实验和流式细胞术检测细胞增殖和凋亡，酶标仪检测Calcineurin活性，Western blot检测Calcineurin-NFATc3信号通路相关蛋白的表达。采用CCK-8检测CD8⁺T细胞与SW620细胞共孵育的细胞活力，Western blot检测Calcineurin特异性抑制剂FK506处理SW620细胞后NFATc3和PD-L1蛋白表达。结果 与CCD 841 CoN细胞相比，TRPM8 mRNA和蛋白在SW620细胞中的表达均增加（P<0.01）。与Control siRNA组比较，干涉 TRPM8表达后SW620细胞活力、细胞增殖能力、Calcineurin活性，以及TRPM8、PD-L1和 NFATc3蛋白表达均降低（P<0.01），而细胞凋亡率和p-NFATc3蛋白表达均升高（P<0.01）；过表达TRPM8可增强细胞活力、细胞增殖能力和Calcineurin活性，上调TRPM8、PD-L1及NFATc3蛋白表达（P<0.01），下调p-NFATc3蛋白表达（P=0.002）。CD8⁺ T细胞与干涉TRPM8表达的SW620细胞共孵育后总细胞活力降低（P=0.002），而与过表达SW620细胞共孵育后总细胞活力增强（P=0.005）。FK506处理可抑制SW620细胞Calcineurin活性，下调NFATc3、PD-L1蛋白表达（P<0.01）。结论 TRPM8过表达可能通过激活Calcineurin-NFATc3信号通路而促进PD-L1表达，从而增强结肠癌细胞免疫逃逸能力，促进结肠癌细胞增殖。     

Machine learning algorithm to construct cuproptosis- and immune-related prognosis prediction model for colon cancer

BACKGROUND Over the past few years, research into the pathogenesis of colon cancer has progressed rapidly, and cuproptosis is an emerging mode of cellular apoptosis. Exploring the relationship between colon cancer and cuproptosis benefits in identifying novel biomarkers and even improving the outcome of the disease.AIM To look at the prognostic relationship between colon cancer and the genes associated with cuproptosis and the immune system in patients. The main purpose was to assess whether rea...     

Effect of tumor-derived cytokines and growth factors on differentiation and immune suppressive features of myeloid cells in cancer

It is well established that cancers affect differentiation of dendritic cells and promote systemic expansion of immune suppressive immature myeloid cells. This phenomenon may represent a mechanism of tumor escape from immune attack and could have significant impact on tumor progression. In this review we discuss the role of different tumor-derived factors, which were implicated in abnormal myeloid cell differentiation. The role of reactive oxygen species as well as JAK/STAT signaling in mechanisms of the effects of tumor-derived factors on myeloid cells is also discussed.     

Antiproliferative potency of structurally distinct dietary flavonoids on human colon cancer cells

Dietary flavonoids are known to be antiproliferative and may play an important role in cancer chemoprevention, especially cancers of the gastrointestinal tract, because of a direct contact with food. This study was designed to compare the antiproliferative potency of several structurally distinct dietary flavonoids in colon cancer cells, Caco-2 and HT-29, and in rat nontransformed intestinal crypt cells, IEC-6. Flavonoids varied significantly in their antiproliferative potency depending on the structural features but the observations were consistent among the three cell lines studied. Of the two most potent flavonoids, quercetin and genistein, the effect was found to be dose-dependent and chromatin condensation, an indication of apoptosis, was noticed. Quercetin was found to distribute throughout the cell with higher amounts in the perinuclear and nucleoli areas. The lack of specific cell membrane enrichment by quercetin was consistent with its lack of effect on the transepithelial resistance. While several flavonoids including quercetin were found to be unstable, the chemical instability did not correlate with the antiproliferative potency, although it may contribute to the antiproliferative effect.     

EXPRESSION OF FLIP IN HUMAN COLON CARCINOMAS： A NEW MECHANISM OF IMMUNE EVASION

Objective： It has been proposed that Fas ligand （FasL） may play an important role in immune escape of tumors and FLIP is an important mediator of Fas/FasL pathway. In this study, the expression of FLIP was determined in human colon carcinoma cell lines and tissue to investigate the new mechanism of immune evasion of human colon carcinomas. Methods： RT-PCR and immunohistochemistry （IHC） were performed to investigate the expression of FLIP in human colon carcinoma cell lines SW480, LS174 and twenty human primary colon carcinoma specimens. Results： It was shown that SW480 cells, LS174 cells and primary colon carcinoma specimen constitutively expressed FLIP at the mRNA and protein level. The expression of FLIP was not found in the epithelial cells of normal colon mucosa. Conclusion： FLIP was expressed in human primary colon carcinoma specimens but not in the normal counterpart. It suggested that the expression of FLIP may occur during the malignant transformation from normal colon epithelial cells to colon carcinoma cells. Tumor cells might obtain the ability to resist the Fas-mediated apoptosis by expressing FLIP. The expression of FLIP might contribute to the formation of colon carcinomas.     

Curcumin causes superoxide anion production and p53-independent apoptosis in human colon cancer cells

Curcumin from the rhizome of the Curcuma longa plant has chemopreventative activity and inhibits the growth of neoplastic cells. Since p53 has been suggested to be important for anticancer activity by curcumin, we investigated curcumin-induced cytotoxicity in cultures of p53^+/+ and p53^−/− HCT-116 colon cancer cells, as well as mutant p53 HT-29 colon cancer cells. Curcumin killed wild-type p53 HCT-116 cells and mutant p53 HT-29 cells in a dose- and time-dependent manner. In addition, curcumin-treated p53^+/+ HCT-116 cells and mutant p53 HT-29 cells showed upregulation of total and activated p53, as well as increased expression of p53-regulated p21, PUMA (p53 upregulated modulator of apoptosis), and Bax; however, an equivalent cytotoxic effect by curcumin was observed in p53^+/+ and p53^−/− HCT-116 cells, demonstrating that curcumin-induced cytotoxicity was independent of p53 status. Similar results were obtained when the cytotoxic effect of curcumin was assessed in wild-type p53 HCT-116 cells after siRNA-mediated p53 knockdown. Chromatin condensation, poly (ADP-ribose) polymerase-1 cleavage and reduced pro-caspase-3 levels in curcumin-treated p53^+/+ and p53^−/− HCT-116 cells suggested that curcumin caused apoptosis. In addition, exposure to curcumin resulted in superoxide anion production and phosphorylation of oxidative stress proteins in p53^+/+ and p53^−/− HCT-116 cells. Collectively, our results indicate that, despite p53 upregulation and activation, curcumin-induced apoptosis in colon cancer cells was independent of p53 status and involved oxidative stress. Curcumin may therefore have therapeutic potential in the management of colon cancer, especially in tumors that are resistant to conventional chemotherapy due to defects in p53 expression or function.     

Down-regulation of liver-intestine cadherin enhances noscapine-induced apoptosis in human colon cancer cells

Background: The aim of the present study was to explore the signaling pathway of noscapine which induces apoptosis by blocking liver-intestine cadherin (CDH17) gene in colon cancer SW480 cells.

Methods: Human colon cancer SW480 cells were transfected with CDH17 interference vector and treatment with 10 µmol/L noscapine. The proliferation and apoptosis of SW480 cells were detected by MTT assay and AnnexinV-FITC/PI flow cytometry kit (BD), respectively. Cell invasion were assessed by transwell assays. Apoptosis related proteins (Cyt-c, Bax, Bcl-2 and Bcl-xL) levels were evaluated by western blot.

Results: Compared to the noscapine group, the proliferation was decreased significantly and the apoptosis was increased significantly in SW480 cells of the siCDH17+noscapine group. Cyt-c and Bax protein levels in siCDH17+noscapine group was higher than that of the noscapine group, but Bcl-2 and Bcl-xL protein levels in siCDH17+noscapine group were lower than that of the noscapine group. Moreover, up-expression of CDH17 inhibited the efficacy of noscapine-induced apoptosis in SW480 cells.

Conclusions: We inferred that down-expression of extrinsic CDH17 gene can conspicuously promote apoptosis-inducing effects of noscapine on human colon cancer SW480 cells, which is a novel strategy to improve chemotherapeutic effects on colon cancer.     

TMIGD1在结肠癌中的表达及对结肠癌细胞增殖和侵袭的影响

目的 检测TMIGD1在结肠癌及其相应的癌旁正常结肠上皮组织中的表达情况及过表达TMIGD1对结肠癌细胞生物学行为的影响,并探讨潜在分子机制.方法 通过生物信息学数据库和免疫组织化学染色检测TMIGD1在结肠癌与癌旁正常组织中的表达情况,并分析其与不同临床病理因素之间的关系.对结肠癌细胞系SW480通过慢病毒包装系统使...     

肺癌患者外周血淋巴细胞与癌细胞耐药基因表达的相关性研究

目的：探讨肺癌患者外周血淋巴细胞和癌细胞耐药基因表达的相关性。方法：采用RT—PCR法检测40例肺癌患者外周血淋巴细胞耐药基因MDR-1的表达,免疫组化法检测肺癌组织原代培养癌细胞耐药基因蛋白P—gp和MRP的表达。结果：肺癌患者外周血淋巴细胞耐药基因MDR-1的表达率37．5％（15／40）,与肺癌细胞耐药基因蛋白P—gp和MRP的表达具有相关性（P〈0．05）,与肺癌患者的年龄、分期、病理类型及性别无关（P〉0．05）。结论：外周血淋巴细胞耐药基因MDR-1的表达率较高,与癌细胞耐药基因蛋白P—gp和MRP的表达具有相关性,对肺癌临床化疗药物的选择具有重要的参考价值。     

Selective targeting of human colon cancer stem-like cells by the mTOR inhibitor Torin-1

Metastatic colorectal cancer (CRC) is incurable for most patients. Since mammalian target of rapamycin (mTOR) has been suggested as a crucial modulator of tumor biology, we aimed at evaluating the effectiveness of mTOR targeting for CRC therapy. To this purpose, we analyzed mTOR expression and the effect of mTOR inhibition in cancer stem-like cells isolated from three human metastatic CRCs (CoCSCs).CoCSCs exhibited a strong mTOR complex 2 (mTORC2) expression, and a rare expression of mTOR complex 1 (mTORC1). This latter correlated with differentiation, being expressed in CoCSC-derived xenografts. We indicate Serum/glucocorticoid-regulated kinase 1 (SGK1) as the possible main mTORC2 effector in CoCSCs, as highlighted by the negative effect on cancer properties following its knockdown. mTOR inhibitors affected CoCSCs differently, resulting in proliferation, autophagy as well as apoptosis induction. The apoptosis-inducing mTOR inhibitor Torin-1 hindered growth, motility, invasion, and survival of CoCSCs in vitro, and suppressed tumor growth in vivo with a concomitant reduction in vessel formation. Torin-1 also affected the expression of markers for cell proliferation, angio-/lympho-genesis, and stemness in vivo, including Ki67, DLL1, DLL4, Notch, Lgr5, and CD44. Importantly, Torin-1 did not affect the survival of normal colon stem cells in vivo, suggesting its selectivity towards cancer cells. Thus, we propose Torin-1 as a powerful drug candidate for metastatic CRC therapy.     

Crosstalk between colon cancer cells and macrophages via inflammatory mediators and CD47 promotes tumour cell migration

Tumour-associated macrophages (TAMs) of the M2 phenotype are present in the stroma of many tumours and are frequently associated with the progression of several types of cancer. We investigated the role of M2 macrophages in colon cancer progression and found that human colon cancer tissue had elevated numbers of CD68⁺ (macrophage marker) cells and CD206⁺ (M2 macrophage marker) cells and increased CD47 expression. To explore potential interplay between colon cancer cells and M2 macrophages, we differentiated the monocyte cell line THP-1 into M1 and M2 macrophages (CD206^high and Th2 cytokine-secreting cells), respectively. M2 macrophages migrated faster than M1 macrophages towards SW480-conditioned medium. Similarly, M2 macrophage-conditioned medium induced SW480 cell migration and CD47 expression. Factors released by macrophages were involved in this induction. In addition, SW480 cells migrated faster when co-cultured with M2 macrophages. Inhibition of CD47 with blocking antibodies or siRNA significantly reduced the migration of SW480 cells in the presence of M2 macrophages. This effect was further decreased via blocking antibodies against the CD47 ligand signal-regulatory protein α (SIRPα). Additionally, cancer cells also secreted significant levels of IL-10, thereby promoting M2 macrophage differentiation. These findings indicate that a TAM-enriched tumour microenvironment promotes colon cancer cell migration and metastasis.     

沉默GOLPH3基因表达逆转人结肠癌细胞顺铂耐药的研究

背景与目的：化疗是结肠癌的重要治疗方法之一,其方案常含有铂类药物,而化疗耐药会影响结肠癌疗效和预后,其发生机制与基因异常表达有关。高尔基磷酸化蛋白3（Golgi phosphoprotein 3,GOLPH3）是一个癌基因,在结肠癌组织中存在过表达,可促进结肠癌细胞的增殖,与预后不良相关。目前,GOLPH3基因的高表达与结肠癌对铂类耐药的相关性尚不明确。探讨沉默GOLPH3基因逆转人结肠癌HT29细胞对顺铂的化疗耐药效应和机制。方法：HT29细胞分为5组。① 对照组：人结肠癌HT29细胞;② 转染组：siRNA-GOLPH3转染HT29细胞;③ 实验组1：经顺铂处理的HT29细胞;④ 实验组2：经顺铂处理的siRNA-GOLPH3转染HT29细胞;⑤ 实验组3：经顺铂和细胞外调节蛋白激酶（extracellular signal-regulated protein kinases,ERK）1/2抑制剂PD98059处理的HT29细胞。四甲基偶氮唑蓝（methyl thiazolyl tetrazolium,MTT）法、平板克隆形成实验检测各组结肠癌HT29细胞增殖及克隆形成能力。蛋白质印迹法（Western blot）检测GOLPH3、P-糖蛋白（P-glycoprotein,P-gp）、ERK1/2和pERK1/2蛋白的表达。结果：经顺铂处理后,实验组1、实验组2的细胞在波长490 nm处的吸光度（D）值均显著低于对照组（P<0.05）,实验组2的D₄₉₀值显著低于实验组1（P<0.001）;实验组1和实验组2的细胞集落数均显著低于对照组（P<0.01）,实验组2的细胞集落数显著低于实验组1（P<0.001）。实验组1的P-gp、GOLPH3、pERK1/2蛋白表达量显著高于实验组2（P<0.01）;实验组3的P-gp蛋白表达量较实验组1显著降低（P<0.01）。结论：沉默GOLPH3基因可通过抑制丝裂原活化蛋白激酶/细胞外信号调节激酶（mitogen-activated protein kinase/extracellular signal-regulated kinase,MAPK/ERK）信号通路逆转HT29结肠癌细胞对顺铂化疗的耐药性。     

TNP-470联合5-FU抑制结肠癌生长的实验研究

背景与目的：新生血管生成是肿瘤生长转移的一个重要条件,本研究通过体内外实验观察血管生成抑制剂TNP-470联合5-氟尿嘧啶（5-fluorouracil,5-Fu）对结肠癌生长的影响。方法：采用四甲基偶氮唑盐（MTT）法检测TNP-470和5-Fu对LOVO细胞的生长抑制效应,用Burgi法分析联合用药效果。建立结肠癌皮下移植瘤模型,观察TNP-470单独或联合5-Fu对移植瘤的生长抑制作用,采用免疫组化和图像分析系统定量检测肿瘤组织中血管内皮生长因子（VEGF）的表达,抗Ⅷ因子抗体标记计数肿瘤微血管密度（MVD）。结果：TNP-470和5-Fu对体外培养的LOVO细胞的生长具有抑制作用,半数抑制浓度（IC50）分别为55.8ng/ml和4.6ng/ml,Burgi法分析表明两者联合应用具有协同效应,LOVO细胞生长进一步受到抑制。体内实验表明：各治疗组肿瘤的生长明显受到抑制,而联合治疗组抗瘤作用进一步增强。联合治疗组和5-Fu组肿瘤组织中VEGF的表达较对照组显著减少,联合治疗组和TNP-470组肿瘤组织中的MVD与对照组比较也显著降低。结论：TNP-470能够抑制LOVO细胞及其皮下移植瘤的生长和新生血管形成,与5-Fu联合应用具有协同作用,可提高抗瘤效应。