Proteomics-based evaluation of the mechanism underlying vascular injury via DNA interstrand crosslinks, glutathione perturbation, mitogen-activated protein kinase, and Wnt and ErbB signaling pathways induced by crotonaldehyde

Crotonaldehyde (CRA)—one of the major environmental pollutants from tobacco smoke and industrial pollution—is associated with vascular injury (VI). We used proteomics to systematically characterize the presently unclear molecular mechanism of VI and to identify new related targets or signaling pathways after exposure to CRA. Cell survival assays were used to assess DNA damage, whereas oxidative stress was determined using colorimetric assays and by quantitative fluorescence study; additionally, cyclooxygenase-2, mitogen-activated protein kinase pathways, Wnt3a, β-catenin, phospho-ErbB2, and phospho-ErbB4 were assessed using ELISA. Proteins were quantitated via tandem mass tag-based liquid chromatography-mass spectrometry and bioinformatics analyses, and 34 differentially expressed proteins were confirmed using parallel reaction monitoring, which were defined as new indicators related to the mechanism underlying DNA damage; glutathione perturbation; mitogen-activated protein kinase; and the Wnt and ErbB signaling pathways in VI based on Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and protein–protein interaction network analyses. Parallel reaction monitoring confirmed significant (p < 0.05) upregulation (> 1.5-fold change) of 23 proteins and downregulation (< 0.667-fold change) of 11. The mechanisms of DNA interstrand crosslinks; glutathione perturbation; mitogen-activated protein kinase; cyclooxygenase-2; and the Wnt and ErbB signaling pathways may contribute to VI through their roles in DNA damage, oxidative stress, inflammation, vascular dysfunction, endothelial dysfunction, vascular remodeling, coagulation cascade, and the newly determined signaling pathways. Moreover, the Wnt and ErbB signaling pathways were identified as new disease pathways involved in VI. Taken together, the elucidated underlying mechanisms may help broaden existing understanding of the molecular mechanisms of VI induced by CRA.

[The characteristics of digital subtraction angiography and the analysis of the therapeutic effect of interventional therapy on hemorrhage after partial nephrectomy]

Objective: To investigate the digital subtraction angiography (DSA) manifestations of hemorrhage after partial nephrectomy (PN) for renal tumors, and the safety and efficacy of interventional therapy. Methods: The clinical data, DSA images and interventional treatment of 15 patients undergoing emergency interventional therapy due to hemorrhage after PN in the Department of Interventional Therapy of Beijing University Cancer Hospital from January 2015 to January 2019 were retrospectively analyzed. The DSA manifestations, safety and prognosis of interventional therapy were summarized. Results: Among the 15 patients, 10 had abdominal hemorrhage, 2 had abdominal hemorrhage with hematuria, and 3 had hematuria, all of which occurred 6 hours to 7 days after the operation. The DSA manifestations included contrast medium overflow, local artery wall unevenness, local artery branch expansion, pseudoaneurysm formation and renal arteriovenous fistula. There were 14 survivors, followed up for 6-12 months, and further no bleeding occurred. The success rate of interventional therapy was 100% (14/14), and the success rate of hemostasis was 100% (14/14). One patient died of asphyxia due to intraoperative nausea and vomiting. The creatinine levels were (76.0±11.0), (80.0±9.0), (76.0±9.0) μmol/L before operation, 1 week after operation and 1 month after operation respectively. There was no significant difference in creatinine levels among the three groups (F=3.171, P=0.058). The levels of urea nitrogen before operation, 1 week after operation and 1 month after operation were (6.80±1.04), (7.13±0.89), (6.81±0.79) μmol/L respectively. There was significant difference among the three groups (F=4.322, P=0.024). The level of urea nitrogen at 1 month after operation was significantly lower than that at 1 week after operation (P=0.016), but there was no difference compared with that before operation (P=1.000). Conclusion: Contrast medium overflow, pseudoaneurysm formation and renal arteriovenous fistula were the main manifestations of DSA hemorrhage after PN. Interventional therapy was safe and effective and might be a priority in cases of hemorrhage after PN.

[The regulation of CD44 expression by new tumor suppressor gene Arid2 and the influence of Arid2 on the invasion and metastasis in hepatocellular carcinoma cells]

OBJECTIVE

To investigate the effect of a new tumor-suppressor gene Arid2 on the expression level of CD44 and the mechanism that Arid2 regulates the invasion and metastasis in human hepatocellular carcinoma cells HepG2 and Huh7.

METHODS

Recombinant pGL3-CD44 reporter plasmids were transfected into hepatoma cell lines HepG2 and Huh7 cells infected with adenovirus Arid2(Ad-Arid2). Dual luciferase assays were used to determine the relative luciferase activities of reporter plasmids. Western blot technique was used to detect the influence of Arid2 on the expression of transmembrane glycoprotein CD44. Cell migration assays of tumor cells were employed to observe the impact of overexpression of Arid2 on the invasion and metastasis abilities of tumor cells. The sizes of transplanted tumors were recorded to observe the growth of subcutaneous transplanted tumors in nude mice. Statistical significance was analyzed by one-way ANOVA for multiple comparisons, and independent-samples t-test was utilized to compare two groups.

RESULTS

Luciferase assay showed cells were transfected with different length of CD44 reporter plasmids, and their relative luciferase activities were improved to different degrees, compared with pGL3-Basic control. Meanwhile, the mean luciferase activities of pGL3-CD44 -791~+224bp reporter plasmids were significantly repressed by the overexpression of Arid2 which inhibition rates were up to 73.83%±0.92%(P< 0.05, HepG2) or 48.99%±1.37% (P <0.05, Huh7), compared with Ad-GFP control. Western blot results showed that CD44 protein expression was obviously decreased by overexpression of Arid2. Cell migration assays confirmed that the invasion and metastasis abilities were inhibited by increasing Arid2 expression in Human HepG2 or Huh7 cells, which inhibition rates were 66.95%±0.59%(P< 0.05)in HepG2 cells and 73.86%±0.49%(P< 0.05) in Huh7 cells respectively. The animal experiment results indicated that Arid2 could obviously delay or restrict the subcutaneous transplanted tumors growth in nude mice, which was declined by 98.57%±0.34%(P< 0.05).

CONCLUSION

CD44 promoter activities and protein expressions were significantly down-regulated by Arid2 in vitro. The growth and metastasis of tumors were obviously restrained in the hepatocellular carcinoma cells and nude models. In brief, these researches indicate CD44 may play important roles in the process where the invasion and metastasis of hepatocellular carcinoma cells are under the control of Arid2.The studies introduce and evaluate the relationships between Arid2 and CD44, and further provide a new research direction with the occurrence and development of hepatocellular carcinoma.

miRNA-221 promotes proliferation, migration and invasion by targeting TIMP2 in renal cell carcinoma

INTRODUCTION

MicroRNAs (miRNAs) play important roles in tumorigenesis. In this study, we investigated the role of miR-221 in the development and progression of clear cell renal cell carcinoma (ccRCC).

METHODS

Quantitative real-time PCR (qRT-PCR) was used to measure the expression level of miR-221 in ccRCC tissues and cell lines. Then, we investigated the role of miR-221 to determine its potential roles on renal cancer cell proliferation, migration and invasion in vitro. A luciferase reporter assay was conducted to confirm the target gene of miR-221 and the results were validated in renal cancer cells.

RESULTS

In the present study, we found that miR-221 was significantly increased in ccRCC tissues and cell lines. Knocked-down expression of miR-221 remarkably inhibited cell proliferation, migration and invasion of renal cancer cells. Moreover, at the molecular level, our results suggested that TIMP2 as a direct target of miR-221 through which miR-221 promoted tumor cell proliferation, migration and invasion.

CONCLUSIONS

These findings suggested that miR-221 play an oncogenic role in the renal cancer cell proliferation, migration and invasion by directly inhibiting the tumor suppressor TIMP2, indicating miR-221 act as a potential new therapeutic target for the treatment of ccRCC.

Smooth muscle tumors of the gastrointestinal tract. Expression of ras P21 oncogene product and the association with clinicopathology

Quantitative analysis of ras oncogene product P21 was performed on paraffin blocks from 55 smooth muscle tumors of the gastrointestinal tract by immunofluorescence and flow cytometry. No positive evidence for P21 was found in 5 cases of normal smooth muscle tissues. Eight of 14 leiomyomas were P21 positive (57%) but all of them were lower expressed with fluorescence index (FI) < 1.25, whereas a total of 29 leiomyosarcomas and 12 potential malignant smooth muscle tumors were found to be P21 positive (100%), and the majority were overexpressed with FI > 1.25 (P < 0.005). ras P21 was overexpressed significantly in the tumors with mitotic counts of more than 1/10 high power field (P < 0.005). It was also overexpressed significantly as soon as the mild cytologic atypia of the tumor was found (P < 0.005). Five-year survival rate was significantly higher in the patients with lower-expression of ras P21 than those with overexpression (P < 0.005). It was suggested that the expression of ras oncogene product P21 could be used as an objective parameter in distinguishing malignants from benigns and predicting the prognosis of the patients with smooth muscle tumors of the gastrointestinal tract.