Zhuangkai Liu

Southern Medical University, Shengcheng, Guangdong, China

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Publications (5)10.74 Total impact

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    ABSTRACT: microRNAs (miRNAs) are small, non-coding RNAs of endogenous origin. They have been increasingly shown to have aberrant expression in a number of tumor types. miR-192, -194 and -215 have not been comprehensively investigated using a large number of cases in colorectal cancer (CRC). We extracted total RNA from 107 CRC tissues and three CRC cell lines. Following polyadenylation and reverse transcription, the expression levels of miR-192, -194 and -215 were determined for evaluation of the association between expression levels and clinicopathological characteristics by a quantitative real-time polymerase chain reaction (real-time PCR) method. Finally, we studied the impact of miR-194 on cell proliferation in HCT-116 cells by MTT assay. miR-192, -194 and -215 were significantly downregulated in CRC tissues (all p<0.001, paired t-test) and cancer cell lines (all p<0.05) compared to non-tumor counterparts. Moreover, the expression levels of miR-192, -194 and -215 were demonstrated to be associated with increased tumor sizes (p=0.027, p=0.018, and p=0.027, respectively; Mann-Whitney U test). Also, there were marked correlations among these miRNAs in CRC tissues (all p<0.001, Pearson's regression analysis). Furthermore, we found that the overexpression of miR-194 could significantly inhibit cell proliferation in HTC-116 cells. miR-192, -194 and -215 may be important biological markers as tumor suppressors in the carcinogenesis of CRC.
    Experimental and therapeutic medicine 03/2012; 3(3):560-566. · 0.34 Impact Factor
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    ABSTRACT: MicroRNAs (miRNAs) are small, non-coding RNAs of endogenous origin. Accumulating studies have shown aberrant miRNA expression plays an important role in many tumor types. miR-192 and -215, which have the same "seed region", have not been comprehensively investigated using a large number of cases in gastric cancer. The total RNA was extracted from 118 gastric cancer tissues and three gastric cancer cell lines as well as matched non-tumor adjacent tissues (NATs). After polyadenylation and reverse transcription, expression levels of miR-192 and -215 were determined by real-time PCR and calculation using the 2(-∆∆CT) method for evaluation of the association between miR-192, and -215 expression levels and clinicopathological characteristics. There were no significant differences in miR-192 and -215 expression levels between gastric cancer tissues and non-tumor counterparts (both p > 0.05, paired t-test). Interestingly, miR-192 and -215 were down-regulated in MGC-803 cells, BGC-823 cells and SGC-7901 cells (all p < 0.01, paired t-test). Also, the down-regulation of miR-192 and -215 was demonstrated to be associated with increased tumor sizes (both p = 0.003, Mann-Whitney U test) and advanced Borrmann type tumors (p = 0.015 and p = 0.044, respectively, Kruskal-Wallis H test). Moreover, the expression of miR-192 was significantly lower in the pT4 stage of gastric cancer than in pT1, pT2 and pT3 stages (p = 0.026). Furthermore, there was a strong correlation between miR-192 and -215 in gastric cancer tissues (p < 0.001, Pearson regressions). miR-192 and -215 might be related to the proliferation and invasion of gastric cancer. Potentially, they could become important biomarkers.
    Pathology & Oncology Research 12/2011; 18(3):585-91. · 1.56 Impact Factor
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    ABSTRACT: MiR-194 has been shown to be specifically expressed in the human gastrointestinal tract and may play an antimetastatic role in primary liver cancer cells. However, the role of miR-194 in gastric cancer is still unclear. Total RNA was extracted from tissues of 119 patients with gastric cancer and three gastric cancer cell lines (SGC-7901, MGC-803, and BGC-823). Expression levels of miR-194 were determined by real-time polymerase chain reaction (PCR). Moreover, a MTT proliferation assay and transwell cell invasion assay were performed to study the effect of miR-194 on SGC-7901 cell proliferation and invasion. Finally, we used real-time PCR and western blot to verify which gene was the target of miR-194 in gastric cancer. Though there was no significant difference between cancerous and matching noncancerous tissues, we found patients with lower expression of miR-194 tended to have larger tumor size (P = 0.002) and more advanced pT stage (P = 0.028) in gastric cancer. Moreover, the expression of miR-194 was significantly lower in Borrmann IV type gastric cancer than in Borrmann I, II, and III types (P = 0.019). Furthermore, an in vitro invasion assay indicated that the penetrated cell intensity after miR-194 mimics transfection was significantly lower than the control. However, overexpression of miR-194 had little effect on the SGC-7901 cell cycle and proliferation. The results of real-time PCR and western blot highlighted that miR-194 interacted with N-cadherin and negatively regulated its expression at the translational level. These findings imply that miR-194 might play an important role in gastric cancer invasion and progression.
    Annals of Surgical Oncology 08/2011; 19 Suppl 3:S509-17. · 4.12 Impact Factor
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    ABSTRACT: MicroRNAs (miRNAs) are small, non-coding RNAs of endogenous origin, they have been increasingly shown to have aberrant expression in many tumor types. miR-203 has not been comprehensively investigated in gastric and colorectal cancers. Total RNA was extracted from tissues of 212 patients with gastric or colorectal cancer as well as from seven gastric and colorectal cell lines. We determined the expression of miR-203 by real-time PCR and calculated using the 2-ΔΔCt method. Then, we assessed miR-203 expression and clinicopathologic characteristics. Finally, we studied the effect of miR-203 on cell proliferation in SGC-7901 cells by MTT. miR-203 has significantly low expression in colorectal cancer tissues (p < 0.001, paired t test) and cancer cell lines compared to non-tumor counterparts. Moreover, low expression of miR-203 was correlated with tumor size (p = 0.015, non-parametric test) and pT stage (p = 0.005) in colorectal cancer. Although expression of miR-203 was not significant in gastric cancer tissues (p = 0.124), interestingly, miR-203 was correlated with tumor size (p = 0.023), macroscopic type (p = 0.045), and pT stage (p = 0.013). Furthermore, we found miR-203 can inhibit the cell proliferation in SGC-7901 cells. miR-203 may be related to the proliferation and invasion of gastric and colorectal cancers.
    Journal of Gastrointestinal Surgery 11/2010; 15(1):63-70. · 2.36 Impact Factor
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    ABSTRACT: MicroRNAs are endogenous small noncoding RNAs that aberrantly expressed in various carcinomas. MiR-148a and miR-152, which have the same "seed region", have not been comprehensively investigated in gastrointestinal cancers. Total RNA was extracted from the tissues of 101 patients with gastric cancer and 101 patients with colorectal cancer as well as their matched nontumor adjacent tissues. After polyadenylation and reverse transcription, the expression of miR-148a and miR-152 was determined using quantitative real-time polymerase chain reaction. The protein level of cholecystokinin B receptor, which might be the target gene of miR-148a and miR-152, was analyzed by Western blot in 40 patients with gastric cancer. Expression levels of miR-148a and miR-152 in human gastric (p < 0.001 and p = 0.038, respectively, t-test) and colorectal (all p < 0.001) cancers were significantly lower than that in their matched nontumor adjacent tissues. Moreover, their low expression was also found in several gastrointestinal cancer cell lines compared with normal gastric epithelial cell line and normal colorectal tissue, respectively. A strong correlation was found between the expression of miR-148a and miR-152 (all p < 0.001, Pearson's correlation). Furthermore, low expression of miR-152 was correlated with increased tumor size (p = 0.023 and 0.004, respectively, Mann-Whitney U test) and advanced pT stage (p = 0.018 and 0.002, respectively) in gastrointestinal cancers. Low expression of miR-148a was also correlated with increased tumor size (p = 0.045 and 0.018, respectively) in gastrointestinal cancers, but only correlated with advanced pT stage (p = 0.023) in colorectal cancer. We also found the expression of miR-148a (p < 0.001, chi-square test) and miR-152 (p = 0.002) inversely correlated with cholecystokinin B receptor protein in gastric cancer. MiR-148a and miR-152 may be involved in the carcinogenesis of gastrointestinal cancers and might be potential biomarkers in these cancers.
    Journal of Gastrointestinal Surgery 07/2010; 14(7):1170-9. · 2.36 Impact Factor