Girdin locates in centrosome and midbody and plays an important role in cell division.

Girdin is a downstream effector of epidermal growth factor receptor (EGFR)-AKT and interacts with actin and microtubule. Increasing evidence confirmed that Girdin played an important role in cell migration. Here we report that Girdin also regulates cell division. Overexpression or suppression of Girdin leads to attenuated cell proliferation. Imaging of mitotic cells revealed that Girdin is located in the cell division apparatus such as centrosome and midbody. The sub-cellular localization of Girdin was dependent on the domains, which interacted with actin or microtubules. Overexpression of Girdin lead to increased centrosome splitting and amplification. In addition, data show that pAKT also locates in both the centrosome and midbody, indicating the regulating role of AKT in Girdin-mediated cell division. To elucidate the effect of Girdin on tumor growth in vivo, HeLa cells infected with retrovirus harboring either control or Girdin shRNAs were injected subcutaneously into the immunocompromised nude mice. Downregulation of Girdin by shRNA markedly inhibited the cell growth of subcutaneously transplanted tumors in nude mice. These data demonstrate that Girdin is important for efficient cell division. Taking our previous data into consideration, we speculate that Girdin regulates both cell division and cell migration through cytoskeletal molecules.

Upregulation of microRNA-210 regulates renal angiogenesis mediated by activation of VEGF signaling pathway under ischemia/perfusion injury in vivo and in vitro.

BACKGROUND: MicroRNAs (miRNAs) are endogenous, non-coding, small RNAs that regulate gene expression and function, but little is known about regulation of miRNAs in the kidneys under normal or pathologic conditions. Here, we sought to investigate the potential involvement of miRNAs in renal ischemia/reperfusion (I/R) injury and angiogenesis and to define some of the miRNAs possibly associated with renal angiogenesis. METHODS AND RESULTS: Male Balb/c mice were subjected to a standard renal I/R. CD31 immunostaining indicated a significant increase of microvessels in the ischemic region. VEGF and VEGFR2 expression were increased in renal I/R at both the mRNA and protein levels which were detected by qRT-PCR and Western blot, respectively. More importantly, 76 microRNAs exhibited more than 2-fold changes using Agilent microRNA microarray, which contains downregulation of 40 miRNAs and upregulation of 36 miRNAs. Upregulation of miR-210 was confirmed by qRT-PCR with prominent changes at 4 and 24 h after reperfusion. Furthermore, overexpression of miR-210 in HUVEC-12 cells enhances VEGF and VEGFR2 expression and promotes angiogenesis on Matrigel in vitro. CONCLUSION: These findings suggest miR-210 may be involved in targeting the VEGF signaling pathway to regulate angiogenesis after renal I/R injury, which provides novel insights into the angiogenesis mechanism of renal I/R injury.

[Aberrant expression and correlative analysis of P16 in breast cancers].

OBJECTIVE: To evaluate the relationship between the aberrant expression of P16 and the clinic-pathological features in breast cancers. METHODS: In our study, 72 cases of breast cancer were collected and the expressions of P16, HER-2 (human epidermal growth receptor-2), ER (estrogen receptor), PR (progesterone receptor), P53, Ki-67 were measured by immunohistochemistry. The correlations between the P16 and the clinic-pathological features (menstruation, tumor size, histological grade, lymph node metastasis were statistically analyzed. RESULTS: Aberrant expression of P16 was detected in 36.1%(26/72)of breast cancers. Not only was the staining of P16 increased,but also the subcellular localization was changed from nuclear to cytoplasm or whole cell staining. In general, the occasional cell staining (+) usually presented in nuclear, as expression increased, P16 showed mainly in cytoplasm or whole cells (+++) even diffusive staining in extracellular, and the moderate staining was multi-focal both in nuclear and cytoplasm. The expression of P16 was significantly increased in ER negative group compared with ER positive group (78.6% vs. 9.1%,P=0.000). Statistical analysis showed a significant correlation of high Ki-67 index with the group of P16 positive (Z =-0.263, P=0.003). In addition, significant difference was calculated between pre- and post-menopause (55.6% vs. 24.4%, P=0.008)and P16 expressions were also more credited to the poor-differentiated group in histological grading: 11.8% (2/17) for highly differentiated group, 27.6% (8/29) for moderately differentiated group and 61.5% (16/26) for poorly differentiated group, respectively (P=0.002). CONCLUSION: The aberrant expression of P16 in breast cancers correlated closely with loss of estrogen receptor, high proliferation index or high histological grade, predisposed to the patients of pre-menopause, implicating that the aberrant expression of P16 should be a predictor of poor response to endocrine therapy or more aggressive behavior.

Clinical implications for girdin protein expression in breast cancer.

Girdin is highly expressed in breast carcinomas. Suppression of Girdin inhibited breast cancer cell migration. However, the clinical implications of Girdin as a marker are still unclear. Here we examined 80 breast cancer specimens using immunohistochemistry. Overall, positive Girdin staining was 41.25% in all of the cases. Girdin was strongly expressed in tumors of CerbB2-positive breast cancers (p < .05). Cases with both CerbB2- and Girdin-positive expression had a higher histological grade than the others. These findings indicated the closed relationship between breast cancer progression and Girdin expression. Girdin together with CerbB2 might be a new potential marker for breast cancers.

The level of phosphorylated Akt predominantly reflects the expressive status of CerbB2 in invasive breast cancer.

Although some evidence has been documented on EGFR/PI3K mediation of Akt activation in breast cancers, ILK and DNA-PK have not been investigated so far. The aim of this study was to analyze the expression of phosphorylated Akt (pAkt) in breast cancer, with respect to its upstream regulators. The immunostaining of pAkt (Ser473) in 70 invasive breast cancers revealed that status of CerbB2 could play a major role in Akt phosphorylation, while ILK was also involved in the stimulated level of pAkt. The results would provide an important clue for the activation of Akt and potential targeted therapy in breast cancer.

Girdin correlated with autophagy in invasive ductal breast carcinomas.

AIMS AND BACKGROUND: Increasing evidence claims that autophagy is essential for breast cancer progression. Girdin was found highly expressed in breast cancers. It has been reported that Girdin attenuates autophagy in HeLa cells. We explored the relationship between Girdin expression and autophagic patterns in breast cancer. METHODS AND STUDY DESIGN: In the study, Girdin expression and autophagic activity were investigated in a series of 99 invasive ductal breast carcinomas after immunohistochemical staining for the autophagy-associated proteins LC3-II and Girdin. RESULTS: The level of Girdin expression negatively correlated with LC3-II level, which represents autophagic activity (r = -0.289), and positively correlated with lymph node metastasis (r = 0.472). Girdin level was found no different in the "diffuse cytoplasmic" and "stone-like" patterns of LC3-II. CONCLUSIONS: Up-regulated autophagy was negatively associated with Girdin level. There was a significant correlation between Girdin expression and lymph nodes metastasis in invasive ductal breast carcinoma.