Investigation of Rho-Kinase Expressions and Polymorphisms in Mantle Cell Lymphoma Patients

ROCK2 Polymorphism and Expression Contribute to Increased Susceptibility and Poor Prognosis in Hepatocellular Carcinoma

Aim

To analyze the association between ROCK2 gene polymorphism/expression and susceptibility/prognosis of hepatocellular carcinoma (HCC).

Methods

Peripheral venous blood from 204 hepatocellular carcinoma patients (HCC group), 242 chronic hepatitis B patients (CHB group), 215 liver cirrhosis patients (LC group) and 201 healthy volunteers (normal group) were collected. ROCK2 gene (including the rs9808232 locus) was amplified by PCR and the products were sequenced. Tumor tissues from patients with HCC and liver tissues from CHB, LC and normal groups were collected, and mRNA and protein expression of ROCK2 gene in liver tissues were tested by RT-qPCR and immunofluorescence, respectively.

Results

Compared with the normal group, the mRNA and protein expression levels of ROCK2 in the HCC group increased significantly (P < 0.05), but there are no obvious increases in the CHB and LC groups (P > 0.05). ROCK2 gene rs9808232 polymorphism was associated with an increased susceptibility of HCC, and genotypes AC and CC may be risk factors for HCC (P < 0.001). There was a significant association between the ROCK2 gene rs9808232 polymorphism and the route of metastasis in HCC patients (P < 0.05). According to the Kaplan–Meier analysis, the overall survival of patients with AC and CC genotypes of ROCK2 rs9808232 was much shorter than that of patients with AA genotype (median overall survival, 25.5 months vs 16.0 months; Log rank P = 0.006). The overall survival time of patients with high ROCK2 expression is much shorter than that of patients with low ROCK2 expression (median overall survival time, 15.0 months vs 20.5 months; Log rank P = 0.008). Compared with genotype AA, the ROCK2 protein levels of genotypes AC and CC were distinctly increased in the HCC group, especially genotype CC (P< 0.05).

Conclusion

ROCK2 gene rs9808232 polymorphism may contribute to its expression in liver tissue, which may increase the susceptibility and poor prognosis of HCC.

Selective dysregulation of ROCK2 activity promotes aberrant transcriptional networks in ABC diffuse large B-cell lymphoma

Activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL) is an aggressive subtype of lymphoma usually associated with inferior outcomes. ABC-DLBCL exhibits plasmablastic features and is characterized by aberrancies in the molecular networks controlled by IRF4. The signaling pathways that are dysregulated in ABC-DLBCL are, however, not fully understood. ROCK2 is a serine-threonine kinase whose role in lymphomagenesis is unknown. Here we show that ROCK2 activity is constitutively dysregulated in ABC-DLBCL but not in GCB-DLBCL and BL. We furthermore show that ROCK2 phosphorylates IRF4 and that the ROCK2-mediated phosphorylation of IRF4 modulates its ability to regulate a subset of target genes. In addition to its effects on IRF4, ROCK2 also controls the expression of MYC in ABC-DLBCL by regulating MYC protein levels. ROCK inhibition furthermore selectively decreases the proliferation and survival of ABC-DLBCL in vitro and inhibits ABC-DLBCL growth in xenograft models. Thus, dysregulated ROCK2 activity contributes to the aberrant molecular program of ABC-DLBCL via its dual ability to modulate both IRF4- and MYC-controlled gene networks and ROCK inhibition could represent an attractive therapeutic target for the treatment of ABC-DLBCL.