Identification of phosphorylated serine-15 and -82 residues of HSPB1 in 5-fluorouracil-resistant colorectal cancer cells by proteomics

To identify the proteins involved in 5-fluorouracil (5-FU) resistance, a comparison of the total and phosphorylated proteins between the human colorectal cancer (CRC) cell line DLD-1 and its 5-FU-resistant subclone DLD-1/5-FU was performed. Using 2-DE and MALDI-TOF/TOF-based proteomics, 17 up-regulated and 19 down-regulated protein spots were identified in the 5-FU-resistant DLD-1/5-FU cells compared with the parent cell lines. In DLD-1/5-FU cells, 7 anti-apoptotic proteins (HSPB1, proteasome subunit α-5, transitional endoplasmic reticulum ATPase, 14-3-3 β, 14-3-3 γ, 14-3-3 σ, and phosphoglycerate kinase 1) were up-regulated and 4 proapoptotic proteins (cofilin-1, pyruvate kinase M2, glyceraldehyde-3-phosphate dehydrogenase, and nucleophosmin) were down-regulated. The results show that the acquired drug resistance of DLD-1/5-FU cells is caused by the prevention of drug-induced apoptosis, in particular through the enhanced constitutive expression of HSPB1 and its phosphorylated form. Short interfering RNA knockdown of endogenous HSPB1 in DLD-1/5-FU cells restored the sensitivity to 5-FU. Furthermore, MALDI-TOF/TOF and 2-DE Western blot analysis identified the phosphorylated residues of HSPB1 as Ser-15 and Ser-82 in the main (diphosphorylated) form and Ser-15, Ser-78, and Ser-82 in the minor (triphosphorylated) form. The current findings indicate that phosphorylated HSPB1 may play an important role in 5-FU resistance.     

应用组织芯片检测大肠癌组织中p27和cyclin D1的表达及意义

目的 应用组织芯片检测大肠癌组织中p27和cyclinD1的表达及意义.方法 应用免疫组织化学技术检测人大肠癌组织芯片150芯(包括70例大肠癌组织和5例癌旁组织)中p27和cyclinDl的表达.采用多光谱成像系统对免疫组织化学结果进行图像分析,并用SPSS13.0软件对各组染色分析后的数据做单因素方差分析和SNK(q)检验,检验水准α为0.05.结果 大肠癌组织中P27呈低表达,癌旁组织中呈高表达;大肠癌组织中cyclinD1呈高表达,癌旁组织中cyclinD1呈低表达,2组比较差异均有统计学意义(均P ＜0.05).结论 在大肠癌细胞周期G1/S期调控机制中,cyclinD1作为细胞周期G1／S期调控的正问因子促进细胞增殖;p27具有抑制cyclinD1的作用,从而阻止细胞周期GI/S期的转变,抑制细胞增殖. 统对免疫组织化学结果进行图像分析,并用SPSS13.0软件对各组染色分析后的数据做单因素方差分析和SNK(q)检验,检验水准α为0.05.结果 大肠癌组织中P27呈低表达,癌旁组织中呈高表达;大肠癌组织中cyclinD1呈高表达,癌旁组织中cyclinD1呈低表达,2组比较差异均有统计学意义(均P ＜0.05).结论 在大肠癌细胞周期G1/S期调控机制中,cyclinD1作为细胞周期G1／S期调控的正问因子促进细胞增殖;p27具有抑制cyclinD1的作用,从而阻止细胞周     

大肠肿瘤中PTEN和TGF-β1表达及意义

目的 检测大肠癌及大肠腺瘤中PTEN和TGF-β1蛋白的表达,了解大肠癌临床病理的相关因素.方法 采用SP免疫组化法,检测PTEN和TGF-β1蛋白在大肠组织中的表达及意义.结果 PTEN在正常黏膜、大肠腺瘤、大肠癌组织中的阳性表达率分别为100%、70%和51.61%;而癌旁组织的阳性表达率60.87%,与癌组织相似,两者有明显的同步表达性.大肠癌中PTEN蛋白的阳性表达率明显低于非癌组(P< 0.05).TGF-β1在正常黏膜、大肠腺瘤及大肠癌中的阳性表达率分别为0%、40%、83.87%,癌旁组织为67.39%.正常黏膜组织TGF-β1的表达低于癌旁组织、大肠腺瘤和大肠癌(P< 0.05).PTEN表达随肿瘤分化程度的降低、临床分期提高而降低(P< 0.05),TGF-β1的表达与肿瘤分化程度、临床分期有关(P< 0.05);PTEN与TGF-β1的表达呈负相关.结论 PTEN表达降低和TGF-β1表达升高可能与大肠癌的发生发展密切相关,且可能与大肠癌生物学行为及预后有关.     

The first mutations in the MYH gene reported in Moroccan colon cancer patients

Background

Biallelic germline mutations in the MYH gene cause MYH-associated polyposis (MAP) disease, an autosomal recessive form of inherited colorectal cancer. People with MAP tend to develop attenuated multiple adenomatous colon polyps during their lifetime and will have an increased risk of colorectal cancer. Contrary to familial adenomatous polyposis, the number of adenomas is often lower in MAP (from 5 to 100), and even some patients have recently been reported with no identified adenomas.There have been many investigations into MAP that have been conducted in many different countries. Currently there is limited data on MAP in Morocco, and it is reasonable to think, that the prevalence of this form of genetic predisposition is as high as other autosomal recessive genetic diseases found in countries with high rates of consanguinity.The aim of this study is to examine the frequency of MYH mutations in colorectal cancer and/or attenuated polyposis in Moroccan patients.

Patients and methods

The study population consisted of 62 patients; 52 with colorectal cancer, three of them had attenuated polyposis (2 to 99 adenomatous polyps). 10 other patients were referred to our department for polyposis without colorectal cancer.We carried out DNA analysis in 62 patients to screen for the three recurrent mutations c.494A > G (p.Tyr165Cys), c.1145 G > A (p.Gly382Asp) and c.1185_1186dup, p.Glu396GlyfsX43, whereas 40 subjects were screened for germline MYH mutations in the whole coding sequence of the MYH gene by direct DNA sequencing. All these 40 patients, except two, had colorectal cancer without polyposis.

Results

Three patients with colorectal cancer and attenuated polyposis carried biallelic mutations in the MUTYH gene one with the c.494 A > G mutation, one with the c.1105delC mutation, one with the c.1145 G > A mutation. One patient with 25 adenomas without colorectal cancer carried the c.1145 G > A mutation at a homozygote state and one patient with 3 polyps was heterozygote for the mutation c.1145 G > A. No biallelic mutations of MYH gene were detected in colorectal cancer patients and in patients with small number (< 5) of polyps without colorectal cancer.

Conclusion

We report the first biallelic MYH mutations in four Moroccan patients with clinical criteria of MAP; three of them had colorectal cancer with attenuated polyposis. No MYH mutations were found in colorectal patients without polyposis.Despite the relatively small sample size of the current study, our findings suggest that the MAP is not a frequent cause of colon cancer in Morocco as we had expected, and the molecular analysis of MYH gene should be restricted to patients displaying the classical phenotype of MAP.     

Adenomatous polyposis coli as a predictor of environmental chemical‐induced transgenerational effects related to male infertility

Exposure to toxic environmental chemicals during pregnancy is a ubiquitous threat to health with potentially transgenerational consequences. However, the underlying mechanism of how transgenerational effects occur as part of environmental chemical exposure are not well understood. We investigated the potential molecular changes associated with dibutyl phthalate exposure that induced transgenerational effects, using a rat model. Through the analysis of the Gene Expression Omnibus database, we found some similar studies of environmental exposure induced transgenerational effects. Then, we analyzed one of the studies and our results to identify the adenomatous polyposis coli (APC) gene. This gene participated the most of the pathways and was upregulated in both studies. We used the miRWALK data set to predict the microRNAs which targeted the APC gene. We confirmed the miR‐30 family were significantly downregulated in F3 testis tissues and targeted the APC gene. In conclusion, the miR‐30 family/APC interaction is a potential mechanism for the transgenerational effects induced by the environmental chemical.     

腹腔镜手术对结直肠癌根治术患者免疫功能及临床结局的影响

目的:探讨腹腔镜手术对结直肠癌根治术患者免疫功能和临床结局的影响。方法:选取我院2015年2月-2018年2月收治的50例行手术治疗的结直肠癌患者,按照数字随机原则分成两组,对照组25例采用传统开腹手术,观察组25例采用腹腔镜手术,比较两组术前、术后外周血中CD3~+、CD4~+、CD4~+/CD8~+的变化和胃肠功能的改善情况,术后随访1～3年,记录两组患者的生存情况。结果:术前,两组外周血中T淋巴细胞亚群CD3~+、CD4~+、CD4~+/CD8~+比较差异无统计学意义(P0.05);术后1周、2周,观察组CD3~+、CD4~+、CD4~+/CD8~+比例均显著高于对照组,CD8~+明显低于对照组(P0.05)。观察组术后肠鸣音恢复时间、肛门首次排气时间均显著短于对照组(P0.05),两组随访期并发症发生率、死亡率比较差异无统计学意义(P0.05)。结论:结直肠癌患者行腹腔镜手术治疗能够显著提升其免疫功能,术后胃肠功能恢复较快。     

西妥昔单抗联合化疗治疗K-Ras野生型转移性结直肠癌的疗效及其影响因素分析

目的:探讨西妥昔单抗联合化疗治疗K-Ras野生型转移性结直肠癌(mCRC)的疗效及其影响因素。方法:选取2013年1月～2015年1月河北北方学院附属第一医院收治的K-Ras野生型mCRC患者96例,按照随机数字表法将患者分为对照组(n=48)和观察组(n=48)。对照组给予常规化疗方案治疗,观察组在此基础上给予西妥昔单抗治疗。比较两组临床疗效、中位无进展生存期(PFS)、中位总生存期(OS)以及不良反应发生情况,并分析观察组治疗疗效的影响因素。结果:观察组客观有效率(ORR)和疾病控制率(DCR)分别为54.17%和91.67%,均高于对照组的31.25%和81.25%(P0.05)。观察组患者中位PFS和中位OS均较对照组长(P0.05)。观察组皮肤痤疮样病变发生率高于对照组(P0.05)。单因素分析显示,西妥昔单抗联合化疗治疗K-Ras野生型mCRC的ORR、DCR与年龄、肿瘤部位、肿瘤转移部位、肿瘤分化程度以及西妥昔单抗治疗时间有关(P0.05)。结论:西妥昔单抗联合化疗治疗K-Ras野生型mCRC疗效确切,预后较好,患者对不良反应可耐受,患者年龄、肿瘤部位、转移部位、分化程度及西妥昔单抗治疗时间可能是其疗效的影响因素。     

The mismatch repair-dependent DNA damage response: Mechanisms and implications

An important role for the DNA mismatch repair (MMR) pathway in maintaining genomic stability is embodied in its conservation through evolution and the link between loss of MMR function and tumorigenesis. The latter is evident as inheritance of mutations within the major MMR genes give rise to the cancer predisposition condition, Lynch syndrome. Nonetheless, how MMR loss contributes to tumorigenesis is not completely understood. In addition to preventing the accumulation of mutations, MMR also directs cellular responses, such as cell cycle checkpoint or apoptosis activation, to different forms of DNA damage. Understanding this MMR-dependent DNA damage response may provide insight into the full tumor suppressing capabilities of the MMR pathway. Here, we delve into the proposed mechanisms for the MMR-dependent response to DNA damaging agents. We discuss how these pre-clinical findings extend to the clinical treatment of cancers, emphasizing MMR status as a crucial variable in selection of chemotherapeutic regimens. Also, we discuss how loss of the MMR-dependent damage response could promote tumorigenesis via the establishment of a survival advantage to endogenous levels of stress in MMR-deficient cells.     

Analysis of racial disparities in the treatment and outcomes of colorectal cancer in young adults

BackgroundThe incidence of colorectal cancer (CRC) in young adults is increasing. Minority populations with CRC are known to have worse survival outcomes. The aim of this study is to evaluate adults under age 50 years with CRC by race and ethnicity.MethodsData were obtained from all US hospitals that contributed to the National Cancer Database (NCDB) between 2004 and 2013. Univariate and multivariable testing was done to identify factors associated with patient outcome. Kaplan-Meier analysis and Cox proportional hazards models were used for association between patient characteristics and survival.ResultsA total of 83,449 patients between 18 and 50 years of age were identified. Median age was 45 years (SD ± 6), with male preponderance (53.9%). 72% were non-Hispanic Whites (NHW), Blacks (AA) were 15.1% and Hispanics (who did not identify as Blacks) were 8.3% of the study population. Distribution across stages IIV was 15.6%, 22.4%, 33.9% and 27% consecutively. 41.8% of NHW and 28.4% of AA had rectal cancers (p < 0.001). Despite equally receiving standard of care (SOC) as per national guidelines, AA had significantly lower 5-year survival rates (58.8%) compared to Hispanics (64.8%) and NHW (66.9%; HR 1.42; 1.38-1.46; p < 0.001). Furthermore, NHW (HR 0.85; 0.81-0.88; p < 0.001) and Hispanics (HR 0.75; 0.70-0.79; p < 0.001) were more likely to benefit from chemotherapy compared to AA. SOC utilization was associated with improved survival across all racial groups, especially in AA (HR 0.64; 0.60-0.69; p < 0.001).ConclusionDespite comparable rates of SOC utilization, AA young adults had worse survival outcomes compared to other races. More colon (compared to rectal) cancers in AA may have contributed to their worse outcomes.