[Effect of electroacupuncture on expression of stromal cell derived factor-1α in focal ischemic cerebral tissue of rats with cerebral ischemia/ reperfusion injury].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Baihui" (GV20) and "Zusanli" (ST36) on the expression of stromal cell derived factor-1α (SDF-1α) and CD34 in ischemic cortex tissue of cerebral ische-mia /reperfusion injury (CI/RI) rats, so as to study its mechanisms underlying improving CI/RI. METHODS: Thirty male SD rats were equally and randomly divided into sham operation, model and EA groups (n=10 rats in each group). The CI/RI model was established by occlusion of the middle cerebral artery for 120 min, followed by reperfusion. EA (40 Hz, 1-2 mA) was applied to GV20 and left ST36 for 20 min, once daily for successive 14 days. The neurological deficit severity was assessed by using Longa's and colleagues' methods. The histopathological changes of the ischemic tissues were observed after H.E. staining and the expression of SDF-1α and CD34 in the ischemic cortex tissues was detected by immunohistochemistry. RESULTS: After modeling, the neurological deficit score, and the numbers of SDF-1α and CD34-positive cells in the ischemic cerebral cortex tissue were significantly increased in the model group (P<0.05). Following EA intervention, the increased neurological deficit score was reversed at the 3rd, 7th and 14th day, and the increased SDF-1α and CD34-positive cells were significantly further up-regulated in the EA group (P<0.05). H.E. staining showed tissue edema, widening of the intercellular space, cavitation-like changes, neuronal shrinkage, nuclear pyknosis with hyperchroma or even disappearance, and aggregation of inflammatory and neurogliocytes in the model group. These situations were relatively milder in the EA group. CONCLUSION: EA of GV20 and ST36 can improve neurological function of CI/RI rats, which may be associated with its effect in up-regulating the expression of SDF-1α and CD34 proteins in the ischemic cerebral cortex tissues.

p120-catenin isoform 3 regulates subcellular localization of Kaiso and promotes invasion in lung cancer cells via a phosphorylation-dependent mechanism.

p120-catenin regulates E-cadherin stability at the plasma membrane as well as Rho GTPase activity in the cytoplasm, and also interacts with the transcriptional repressor, Kaiso, in the nucleus. However, the role of different isoforms and the phosphorylated state of p120-catenin in the nucleus is poorly understood. In the present study, we show that p120-catenin isoform 3 interacts with Kaiso in lung cancer cells by immunoprecipitation. Nuclear-cytoplasmic extraction and immunofluorescence confirmed that Kaiso shuttled out of the nucleus via p120-catenin isoform 3. The cytoplasmic enrichment of Kaiso by p120-catenin isoform 3 was abolished due to the inhibition of chromosomal region maintenance-dependent nuclear export via leptomycin. The lung tumor tissue and cell lines expressed higher levels of the serine 288 phosphorylated form. Also, serine 288 phosphorylation in p120-catenin isoform 3 enhanced the binding with Kaiso. Moreover, immunofluorescence and transwell invasion assay showed that the phosphorylation of serine and threonine sites in p120-catenin induced F-actin remodelling and promoted the invasion of lung cancer cells. Collectively, our data establish that p120-catenin isoform 3 regulates the nuclear export of Kaiso and promotes invasion in lung cancer cells via a phosphorylation-dependent mechanism. Serine 288 phosphorylation can contribute to lung cancer progression.

Upregulation of δ-catenin is associated with poor prognosis and enhances transcriptional activity through Kaiso in non-small-cell lung cancer.

δ-Catenin is the only member of the p120 catenin (p120ctn) subfamily that its primary expression is restricted to the brain. Since δ-catenin is upregulated in human lung cancer, the effects of δ-catenin overexpression in lung cancer still need to be clarified. Immunohistochemistry was performed to investigate the expression of δ-catenin and Kaiso, a δ-catenin-binding transcription factor, in 151 lung cancer specimens. A correlation between cytoplasmic δ-catenin and Kaiso expression was also associated with high TNM stage, lymph node metastases and poor prognosis. Co-immunoprecipitation assay confirmed the interactions of δ-catenin and Kaiso in lung cancer cells. In addition, gene transfection and RNAi technology were used to demonstrate that increased δ-catenin expression was promoted, whereas its knockdown suppressed its lung cancer invasive ability. In addition, methylation-specific PCR and ChIP assay demonstrated that δ-catenin could regulate MTA2 via Kaiso in a methylation-dependent manner, while it could regulate cyclin D1 and MMP7 expression through Kaiso in a sequence-specific manner. In conclusion, a δ-catenin/Kaiso pathway exists in lung cancer cells. Increased δ-catenin expression is critical for maintenance of the malignant phenotype of lung cancer, making δ-catenin a candidate target protein for future cancer therapeutics.

delta-Catenin promotes malignant phenotype of non-small cell lung cancer by non-competitive binding to E-cadherin with p120ctn in cytoplasm.

As a member of the catenin family, little is known about the clinical significance and possible mechanism of delta-catenin expression in numerous tumours. We examined the expression of delta-catenin by immunohistochemistry in 115 cases of non-small cell lung cancer (NSCLC) (including 65 cases with follow-up records and 50 cases with paired lymph node metastasis lesions). The mRNA and protein expression of delta-catenin was also detected in 30 cases of paired lung cancer tissues and normal lung tissues by RT-PCR and western blotting, respectively. Co-immunoprecipitation was used to examine whether delta-catenin competitively bound to E-cadherin with p120ctn in lung cancer cells or not. The effects of delta-catenin on the activity of small GTPases and the biological behaviour of lung cancer cells were explored by pull-down assay, flow cytometry, MTT, and Matrigel invasive assay. The results showed that the mRNA and protein expression of delta-catenin was increased in lung cancer tissues; the positive expression rate of delta-catenin was significantly increased in adenocarcinoma, stage III-IV, paired lymph node metastasis lesions, and primary tumours with lymph node metastasis (all p < 0.05); and the postoperative survival period of patients with delta-catenin-positive expression was shorter than that of patients with delta-catenin-negative expression (p < 0.05). No competition between delta-catenin and p120ctn for binding to E-cadherin in cytoplasm was found in two lung cancer cell lines. By regulating the activity of small GTPases and changing the cell cycle, delta-catenin could promote the proliferation and invasion of lung cancer cells. We conclude that delta-catenin is an oncoprotein overexpressed in NSCLC and that increased delta-catenin expression is critical for maintenance of the malignant phenotype of lung cancer.

Overexpression of SCC-S2 correlates with lymph node metastasis and poor prognosis in patients with non-small-cell lung cancer.

The objective of the current study was to investigate the expression pattern and clinicopathological significance of SCC-S2 in patients with non-small-cell lung cancer (NSCLC). The expression profile of SCC-S2 in NSCLC tissues and adjacent noncancerous lung tissues was detected by real-time RT-PCR, western blot analysis, and immunohistochemistry. In 25 lung cancer tissues examined, 18 (72%) of them exhibited stronger levels of SCC-S2 mRNA compared with their corresponding normal tissues. SCC-S2 protein level was up-regulated in cancerous lung tissues compared to adjacent normal tissue. Moreover, the expression level of SCC-S2 in 93 archived NSCLC tissues was measured by immunohistochemical staining. SCC-S2 was found to be overexpressed in 71 of 93 (76.3%) human lung cancer samples and correlated with lymph node metastasis (P = 0.0181), p-TNM stage (P = 0.0042), Ki-67 expression (P = 0.0028), and poor survival (P = 0.012). In addition, depleting SCC-S2 expression by small-interfering RNA inhibited growth and invasion in lung cell lines. These results indicate that SCC-S2 plays an important role in NSCLC and might be a useful therapeutic target of NSCLC.

Downregulation of HDPR1 is associated with poor prognosis and affects expression levels of p120-catenin and beta-catenin in nonsmall cell lung cancer.

HDPR1 (human homologue of Dapper) is considered as a Dishevelled (DVL) antagonist in WNT signaling. We recently reported that DVL was associated with cytoplasmic accumulation of beta-catenin in nonsmall cell lung cancer (NSCLC). Whether cytoplasmic accumulation of beta-catenin is correlated with HDPR1 is unclear. Xenopus Dapper (XDpr) was found to stabilize p120-catenin (p120ctn) in Xenopus embryogenesis. However, whether HDPR1 can regulate p120ctn expression level is not reported. Furthermore, how HDPR1 influences invasiveness in lung carcinogenesis is also not well understood. In this study, our aims were to explore the effects of HDPR1 on the lung carcinogenesis and to examine the relationship among HDPR1, beta-catenin, and p120ctn. Immunohistochemical analysis in 120 NSCLC tissues showed that HDPR1 was significantly lower in 82 specimens (68.3%). Reverse transcription (RT)-polymerase chain reaction (PCR) and Western blotting analysis showed that the mRNA and protein expression of HDPR1 were lower in tumor tissues as compared to corresponding nontumorous tissues. Moreover, reduced HDPR1 expression was related to the clinicopathological factors and was an independent risk factor for prognosis of the patients with NSCLC. In addition, HDPR1 expression was also associated with the expression of p120ctn and beta-catenin in lung cancer tissues. Knockdown of HDPR1 gene enhanced the invasive ability of lung cancer cells, which was dependent on p120ctn and independent of beta-catenin. In conclusion, the function of HDPR1 on regulating p120ctn may play an important role in human lung carcinogenesis. Restoration of HDPR1 gene may be a new therapeutic target of lung cancer.

Kaiso is expressed in lung cancer: its expression and localization is affected by p120ctn.

BACKGROUND: Kaiso is a recently identified transcription factor that binds to p120-catenin (p120ctn), an Armadillo catenin and cell adhesion cofactor. However, clinical studies of human solid tumors have not been reported to investigate relationship between these proteins. METHODS: Expression and localization of Kaiso and p120ctn were examined in 196 lung cancer specimens (including 55 cases of paired lymph node metastases and 80 cases with complete follow-up records) by immunohistochemistry. Three lung cancer cell lines, BE1, SPC, and A549 were used to establish p120ctn stably ablated or overexpressed cell lines. Co-immunoprecipitation was used to confirm p120ctn bind Kaiso in lung cancer tissue and cell lines. Localization and expression levels of Kaiso were detected via immunofluorescence, cytoplasmic vs. nuclear fractionation Western blot analysis and reverse transcription-polymerase chain reaction. RESULTS: Cytoplasmic Kaiso expression was evident in 115 (58.7%), and abnormal p120ctn expression was noted in 168 (85.7%). Cytoplasmic Kaiso and abnormal p120ctn expressions were associated with higher degree of malignancy (high-stage and lymph node metastases, all P<0.05). Abnormal p120ctn and cytoplasmic Kaiso expressions were higher in matched autologous nodal metastases than in primary growths. The lung cancer-related 5-year survival rate was significantly lower in patients who were cytoplasmic Kaiso-positive (22.9%; P=0.029) or abnormal p120ctn expression (20.6%; P=0.001). Multivariate analysis showed abnormal p120ctn expression was an independent factor defining the clinicopathological characters of patients. Cytoplasmic Kaiso expression was correlated with cytoplasmic p120ctn, they formed Kaiso-p120ctn complex in lung cancer tissues and cell lines. In addition, p120ctn ablation and overexpression altered Kaiso subcellular localization and protein level. Although both isoforms can regulate subcellular localization and protein levels of Kaiso, we found that only p120ctn isoform 3, but not isoform 1, directly interacts with Kaiso. CONCLUSION: p120ctn and Kaiso might co-participate in the progression and lymph node metastasis of lung cancer. p120ctn regulates expression and localization of Kaiso in lung cancer cells.

Cytoplasmic Kaiso is associated with poor prognosis in non-small cell lung cancer.

BACKGROUND: Kaiso has been identified as a new member of the POZ-zinc finger family of transcription factors that are implicated in development and cancer. Although controversy still exists, Kaiso is supposed to be involved in human cancer. However, there is limited information regarding the clinical significance of cytoplasmic/nuclear Kaiso in human lung cancer. METHODS: In this study, immunohistochemical studies were performed on 20 cases of normal lung tissues and 294 cases of non-small cell lung cancer (NSCLC), including 50 cases of paired lymph node metastases and 88 cases with complete follow-up records. Three lung cancer cell lines showing primarily nuclear localization of Kaiso were selected to examine whether roles of Kaiso in cytoplasm and in nucleus are identical. Nuclear Kaiso was down-regulated by shRNA technology or addition a specific Kaiso antibody in these cell lines. The proliferative and invasive abilities were evaluated by MTT and Matrigel invasive assay, transcription of Kaiso's target gene matrilysin was detected by RT-PCR. RESULTS: Kaiso was primarily expressed in the cytoplasm of lung cancer tissues. Overall positive cytoplasmic expression rate was 63.61% (187/294). The positive cytoplasmic expression of Kaiso was higher in advanced TNM stages (III+IV) of NSCLC, compared to lower stages (I+II) (p = 0.019). A correlation between cytoplasmic Kaiso expression and lymph node metastasis was found (p = 0.003). In 50 paired cases, cytoplasmic expression of Kaiso was 78.0% (41/50) in primary sites and 90.0% (45/50) in lymph node metastases (p = 0.001). The lung cancer-related 5-year survival rate was significantly lower in patients who were cytoplasmic Kaiso-positive (22.22%), compared to those with cytoplasmic Kaiso-negative tumors (64.00%) (p = 0.005). Nuclear Kaiso staining was seen in occasional cases with only a 5.10% (15/294) positive rate and was not associated with any clinicopathological features of NSCLC. Furthermore, after the down-regulation of the nuclear expresses Kaiso in vitro, both proliferative and invasive abilities of three cancer cell lines were significantly enhanced, along with the up-regulation of Kaiso target gene, matrilysin. CONCLUSION: Our data suggest cytoplasmic Kaiso expression is associated with poor prognosis of NSCLC and various subcellular localizations of Kaiso may play differential biological roles in NSCLC.

Abnormal expression of p120-catenin, E-cadherin, and small GTPases is significantly associated with malignant phenotype of human lung cancer.

Studies on a variety of cell lines have shown that p120-catenin can directly regulate the stability of E-cadherin complexes and control the activity of small GTPases to influence cell adhesion. Despite this data, clinical studies of human solid tumors have not been reported to investigate these protein interactions. To explore the correlation between p120-catenin, E-cadherin, and small GTPases in human lung cancer, we examined the expression patterns of p120-catenin, E-cadherin, RhoA, Cdc42, and Rac1, and their prognostic significance in 138 patients with non-small cell lung cancer (NSCLC). While normal bronchial epithelium showed strong membrane expression of p120-catenin and E-cadherin, lung cancer tissues had reduced membrane expression and ectopic cytoplasmic expression of p120-catenin and E-cadherin. Expression of RhoA, Cdc42, and Rac1 was also found to be higher in tumor tissue than in normal lung tissue. A correlation between abnormal p120-catenin, E-cadherin expression, and overexpression of specific small GTPases was also associated with poor differentiation, high TNM stage, and lymph node metastasis in NSCLC patients. We also used an in vitro model to evaluate their expression, and to determine whether protein expression correlated with the invasive capacity of lung cancer cell lines. Consistent with our in vivo data, abnormal expression of p120-catenin and E-cadherin with overexpression of specific small GTPases were significantly associated with the high metastatic capacity of BE1 cells. Based on our results, we conclude that abnormal p120-catenin expression correlates with abnormal E-cadherin expression and specific small GTPase overexpression, which contribute to the malignancy-related to NSCLC.