Expression of ERK5 in colorectal cancer tissues and its correlation with distant metastasis in colorectal cancer patients

AIM: To investigate the expression of extracellular signal-regulated kinase 5 (ERK5) in primary colorectal cancer (CRC) and adjacent normal mucosa, and to analyze the relationship between ERK5 expression and clinicopathological parameters for exploring the functions of ERK5 in the occurrence and development of CRC. METHODS: The expression of ERK5 in carcinoma tissues and normal mucosa was examined by a set of tissue microarrays and the method of immunohistochemistry. The potential relationship between ERK5 expression and clinicopathological features was also analyzed. RESULTS: ERK5 expression was significantly higher in CRC tissues (134/338, 39.6%) than that in normal tissues (21/80, 26.2%; P<0.05). Overexpression of ERK5 in CRC tissues was significantly correlated with distant metastasis (P<0.05). However, no correlation between ERK5 expression and age at surgery, sex, tumor location, the depth of invasion, lymph node metastasis, TNM staging or differentiation grade was found (P>0.05). According to the Kaplan-Meier analysis, there is no significant difference in 5-year overall survival between the patients with ERK5 expression at high level and at low level. CONCLUSION: ERK5 protein is highly expressed in CRC with distant metastasis. This may be a promotive factor in the process of distant metastasis.     

Association between survivin promoter -31C/G polymorphism and genetic susceptibility to sporadic colorectal cancer

AIM: To investigate the association between -31C/G polymorphism in the promoter of survivin gene and the susceptibility to sporadic colorectal cancer (CRC) in southern Chinese population. METHODS: survivin -31C/G genotypes were determined by PCR-RFLP in 711 healthy controls and 702 CRC cases. RESULTS: The number of CRC patients carrying with CC genotype was much higher than that of controls (36.5 % vs 26.2%,2 =17.89,P<0.01). Compared to CC genotypes, CG, GG genotypes and G allele carriers had a significantly decreased risk of CRC, with the decrease being 0.61-fold (95% confidence interval=0.46-0.80, P<0.01), 0.52-fold (95% confidence interval=0.38-0.71,P<0.01) and 0.58-fold (95% confidence interval=0.45-0.74, P<0.01), respectively. CONCLUSION: survivin gene -31C/G polymorphism is associated with sporadic CRC risk, the G variant genotype is the independent protective factors against sporadic CRC in southern Chinese population.     

Investigating the correlation between MTDH/AEG-1 gene 5'-UTR polymorphism and genetic susceptibility to sporadic colorectal cancer

AIM: To assess the correlation between MTDH/AEG-1 gene 5'-UTR polymorphism and genetic susceptibility to sporadic colorectal cancer (CRC) in southern Chinese population by TaqMan-MGB fluorescence probes. METHODS: A case-control study was carried out on southern Chinese population to collect blood DNA samples (693 sporadic CRCs and 660 controls respectively) to investigate MTDH/AEG-1 gene 5'-UTR polymorphism by TaqMan-MGB probes. RESULTS: The distribution of MTDH/AEG-1 5'-UTR genotypes (-1 913C/G,-797G/A) had no significance between CRCs and controls. But GG genotype of -1 913C/G could increase the susceptibility of CRC in drinker(OR=1.71,95%CI=1.13-2.57) and female(OR=1.48, 95%CI= 1.01-2.17), -1 913GG had interaction with drinking and female gender to increase the risk of CRC( P<0.01); Mutated genotypes of -797(GA+AA) also could increase the susceptibility of CRC in drinker (OR=1.55,95%CI= 1.06-2.27) and person with family history of cancer(OR=3.48,95%CI= 1.60-7.57), -797(GA+AA) had interaction with drinking and positive family history of cancer to increase the risk of CRC( P<0.01). But both polymorphisms were not interacted with age, smoking and fatness. CONCLUSION: MTDH/AEG-1 gene 5'-UTR polymorphism has no significant relevance with sporadic CRC susceptibility, but is irrelevant with drinking, gender and family history of cancer to increase the risk of CRC.     

Study on the association of the polymorphism at the position -418A/G and -384C/T in the Apo(a) promoter

AIM: To investigate two single nucleotide polymorphisms (SNP) in the apolipoprotein(a) promoter at positions -418 and -384 and to compare distributing difference of genotype frequencies of single nucleotide among different races and to explore the influencies of them on serum lipid level and their association with coronary heart disease (CHD). METHODS: Using PCR-RFLP (BsgI,BfaI) method, we determined genotypes of these two SNPs in 156 unrelated healthy controls of HanZu Chinese and 56 unrelated CHD patients of HanZu Chinese and 56 unrelated African Blacks, then cloned polymerase chain reaction (PCR) products into T-vector and sequenced it by M13 currency primer, correspondingly. RESULTS: (1) There was no polymorphism at position -418A/A and -384C/C in control group. Only one CHD patient's genotype determined was -418G/G, other were -418A/A and -384C/C in CHD patients. (2) Only two African Blacks' genotype determined was -418G/G, other were -418A/A and -384C/C in African Blacks. (3) However, the Apo(a) promoter sequence was in coincident with the sequence publicized in GenBank and the base at positions -418 was adenine (A) and -384 was cytosine (C). CONCLUSION: The mutation frequencies at position -418 and -384 were low in the Chinese Han Population of Hubei and perhaps no single nucleotide polymorphisms was at two positions. No association with serum lipid levels and CHD was observed. There were great variabilities to the SNPs in the Apo(a) promoter among different races.     

Role of ERK5 in platelet activation in vitro and arterial thrombosis in vivo

AIM: To investigate the role of extracellular signal-regulated kinase 5 (ERK5) in platelet aggregation in vitro and arterial thrombosis in vivo. METHODS: The expression and phosphorylation levels of ERK5 in human platelet were detected by Western blot. The effects of ERK5 selective inhibitor XMD8-92 on platelet aggregation and dense granule secretion were detected by Chrono-Log aggregometer. The effect of ERK5 on in vivo thrombosis was analyzed using an FeCl₃ artery thrombosis model. The effects of XMD8-92 on protein kinase B (PKB/Akt) and phosphatase and tensin homolog deleted on chromosome ten (PTEN) phosphorylation levels were determined by Western blot. RESULTS: ERK5 was stably expressed in human platelets and its phosphorylation level increased significantly after platelet activation (P<0.05). XMD8-92, a selective inhibitor of ERK5, inhibited platelet aggregation and dense granule secretion in response to several platelet stimulators (P<0.05). The results of Western blot showed that XMD8-92 inhibited Akt phosphorylation level by down-regulating PTEN Ser370 phosphorylation and enhancing PTEN activity. The pathway was further confirmed using platelet specific PTEN deficiency mice. The first occlusion time was obviously extended in the mice intravenously given XMD8-92 in the FeCl₃-induced carotid artery injury model. CONCLUSION: ERK5 plays a role in platelet activation and arterial thrombosis by influencing PTEN and Akt phosphorylation.     

Effects of SM22α on migration and invasion abilities of colorectal cancer cells

AIM:To explore the effects of smooth muscle 22α protein (SM22α) on the migration and invasion abilities of colorectal cancer cells, and to investigate its molecular mechanism. METHODS:The SM22α-over-expressing cells were constructed by lentivirus transfection. The cell migration ability was detected by wound healing assay. The changes of cell migration and invasion abilities were measured by Transwell assay. RT-qPCR was used to detect the changes of SM22α mRNA level. The protein levels of extracellular signal-regulated kinase (ERK), p-ERK, matrix metalloproteinase-9 (MMP-9) and SM22α were determined by Western blot. RESULTS:HCT116 cells with SM22α over-expression were constructed successfully. SM22α inhibited the migration and invasion abilities of colorectal cancer cells. SM22α over-expression decreased the protein levels of p-ERK and MMP-9 (P<0.05).CONCLUSION:SM22α inhibits the migration and invasion abilities of colorectal cancer cells by inhibiting ERK/MMP-9 signaling pathways.     

Relationship between UGT1A1 gene polymorphisms and toxicity/efficacy of irinotecan-based chemotherapy in metastatic colorectal cancer

AIM: To investigate the correlation of UGT1A1 ^*28 and UGT1A1 ^*6 gene polymorphisms with irinotecan-associated adverse events and efficacy in the patients with metastatic colorectal cancer (mCRC) treated with irinotecan-based chemotherapy. METHODS: Analysis of UGT1A1 ^*28 and UGT1A1 ^*6 gene polymorphisms was performed in 207 gastrointestinal cancer patients admitted to our hospital from April 2010 to March 2012 by amplifying the gene fragments using PCR and direct sequencing. Fifty six cases with mCRC treated with irinotecan were chosen to observe the adverse events and efficacy during chemotherapy, and the time to progression (TTP) was also recorded. The incidence of different genotypes was compared. RESULTS: The distribution of the genotypes in 207 gastrointestinal cancer patients was as follows: UGT1A1 ^*28 wild-type (WT) genotype TA6/6 (164, 79.2%), heterozygous genotype TA6/7 (41, 19.8%), and homozygous genotype TA7/7 (2, 1.0%); UGT1A1 ^*6 WT genotype G/G (154, 74.4%), heterozygous genotype G/A (51, 24.6%), and homozygous genotype A/A (2, 1.0%). In the 56 mCRC cases, the incidence of grade 3 and 4 delayed diarrhea and neutropenia in the patients carrying UGT1A1 ^*6 (G/A and A/A) was higher than that in the WT genotype (6/6) (38.9% vs 7.9%,61.1% vs 29.0%, both P<0.05). The incidence of grade 3 and 4 thrombocytopenia in the patients carrying UGT1A1 ^*28 (TA6/7 and TA7/7) was higher than that in the WT genotype (TA6/6) (33.3% vs 2.1%, P<0.05). No significant difference of TTP and chemotherapeutic effect was observed between different genotypes. CONCLUSION: The UGT1A1 ^*6 (G/A and A/A) genotypes increase the risk of grade 3 and 4 delayed diarrhea and neutropenia, and the UGT1A1 ^*28 (TA6/7 and TA7/7) genotypes increase the risk of grade 3 and 4 thrombocytopenia in mCRC patients treated with irinotecan-based chemotherapy.     

Relationships between lncRNA HOTAIR/H19 SNPs and genetic susceptibility to gastric carcinoma/EBV-related gastric carcinoma

AIM To investigate the potential associations between the single nucleotide polymorphisms （SNPs） of long noncoding RNA （lncRNA） H19/HOTAIR and the susceptibility to gastric carcinoma, especially to Epstein-Barr virus （EBV）-associated gastric carcinoma （EBVaGC）. METHODS Peripheral blood samples from 65 cases of EBV-negative gastric carcinoma （EBVnGC）, 50 cases of EBVaGC and 115 cases of healthy people were collected. A total of 4 TagSNPs, H19 rs3024270 and rs3741219, as well as HOTAIR rs4759314 and rs874945, were selected. The Taq-Man MGB allele typing kit was used to detect the genotype of each SNP locus, and the experimental results were statistically analyzed. RESULTS （1） There were significant differences of both genotypic and allelic frequencies at H19 rs3024270 locus between gastric carcinoma group and control group （P<0.05）. Individuals carrying the G allele at H19 rs3024270 locus had significantly low risk of gastric carcinoma （P<0.01）, indicating that the G allele was protective. （2） People with the GG genotype at HOTAIR rs4759314 locus had significantly high risk of gastric carcinoma （P<0.05）. Carrying the G allele increased the risk of gastric carcinoma, which indicated that the risk gene for gastric carcinoma might be the G allele. （3） No significant difference of the genotypic and allelic frequencies at H19 rs3741219 and HOTAIR rs874945 loci between gastric carcinoma group and control group was observed （P>0.05）.（4） The G allele frequency at HOTAIR rs4759314 locus in EBVaGC group was significantly higher than that in EBVnGC group. However, no difference of the other 3 SNPs was found between EBVaGC group and EBVnGC group （P>0.05）. CONCLUSION The SNPs at H19 rs3024270 and HOTAIR rs4759314 loci are related to the risk of gastric carcinoma, but not significantly related to the risk of EBVaGC.