Regulatory roles of lncRNA PANDAR in breast cancer cell proliferation.

Background: Breast cancer represents the second most deadly malignancy in women, and long noncoding RNAs (lncRNAs) have crucial functions in its development. Objective: To investigate effects of the promoter of CDKN1A antisense DNA damage-activated RNA (PANDAR) on epithelial-mesenchymal transition (EMT) in breast cancer cells and their proliferation. Methods: lncRNAs potentially regulating the transcriptional activity of the E-cadherin (E-cad, an epithelial cell marker) gene promoter were screened using a dual-luciferase reporter assay. PANDAR was overexpressed in Michigan cancer foundation 7 (MCF-7) breast cancer cells. E-cad and N-cadherin (N-cad, a mesenchymal cell marker) levels were detected by immunoblotting. Cell viability was assessed using a cell counting kit-8. Results: PANDAR and TCONS00068220/LOC105375819 conservatively regulated the promoter activity of E-cad. PANDAR overexpression in MCF-7 inhibited E-cad expression, but upregulated N-cad. The enhanced expression of PANDAR promoted cell proliferation. Conclusion: PANDAR is a key transcriptional repressor of E-cad and has regulatory effects on the promotion of cell proliferation. PANDAR is an oncogene in breast cancer, potentially facilitating the EMT process and promoting cell proliferation.

XCHD Inhibits C6 Cell Growth Primarily via the p53/Caspase Pathway.

The effects of XCHD on the proliferation of C6 cells and on factors associated with the microRNA-34a (miR-34a)/p53/caspase-3 signaling pathway in vitro were investigated. Methods. XCHD was purchased too much to complete the study. CCK-8 assay was used to measure the XCHD concentration, and qPCR was used to quantify miR-34a expression at the mRNA level. Apoptosis was assessed using TUNEL. Western blots were used to determine the p53, caspase-3, caspase-8, and Bcl-2 expression levels. Results. The optimal XCHD concentration and time effect for C6 cells were observed after 36 h of exposure to a concentration of 100 µg/ml XCHD. miR-34a expression increased 8 and 12 h after the addition of XCHD. The presence of XCHD decreased Bcl-2 expression but increased p53, cleaved caspase-3, Bax, and caspase-8 expression. When p53 was inhibited, miR-34a expression was unaffected by the addition of XCHD, Bcl-2 expression was low, and cleaved caspase-3, Bax, and caspase-8 expression increased. The inhibition of p53 promoted C6 cell growth when compared with C6 cells exposed to XCHD and with no inhibition of p53. Conclusions. XCHD inhibits C6 cell growth which was influenced by the p53/caspase pathway.

Transforming growth factor-ß1 regulates epithelial-mesenchymal transition in association with cancer stem-like cells in a breast cancer cell line.

Epithelial-mesenchymal transition (EMT) is associated with altered connection and junctions between cells and changes in abilities of invasion and migration. In this study, we investigated whether SK-BR-3 breast cancer cells induced to undergo EMT exhibit changes in morphological and invasion abilities after Transforming growth factor ß1 (TGF-ß1) treatment. Serum-deprived SK-BR-3 cells were treated with TGF-ß1 (0, 10 ng/mL) for 24 h. The cells morphological changes were observed and imaged using inverted phase contrast microscope. Scratch experiment and invasion experiment were employed to detect changes of invasion ability, cell-flow experiment was used to assess cell cycle, immunohistochemistry technique was used to detect epithelial and mesenchymal markers after the crawling cells were fixed. Our research reveal that SK-BR-3 cells become larger and more messy, the elongated cells extend pseudopodia, the link of the cells became more loosely and cell gap widened after TGF-ß1 treatment. SK-BR-3 cells showed faster growing and improved invasion abilities after TGF-ß1 treatment, and reduced G1 phase cells proportion in the total number of cells after the conversion, in contrast the S phase cells accounted for the proportion of the total number of cells increased. These findings indicate that TGF-ß1-induced EMT in breast cancer cells may be associated with major alterations in morphological and invasion abilities.

Clinicopathological significance of PTEN and PI3K/AKT signal transduction pathway in non-small cell lung cancer.

A high frequency of mutations at the PTEN locus has been noticed in carcinoma of lung. However, the role of PTEN alternations and its association with outcome variables in the genesis of lung carcinoma are not understood fully. The purpose of our study was to examine the impact of EGFR, TGF-α, P-AKT and PTEN in the genesis of non-small cell lung cancer (NSCLC). Total numbers of 66 histopathologically confirmed cases of NSCLC and 10 cases of benign control samples embedded with wax were studied. We assessed EGFR, TGF-α and P-AKT by the use of specific antibody through immunohistochemistry as directed by the manufacturer, and detected PTEN expression by in situ hybridization. There were progressive loss of PTEN expression and significant increasing in EGFR, TGF-α, P-AKT expression from benign samples to NSCLC (p<0.05). The overexpression of EGFR, TGF-α, P-AKT and loss of PTEN expression were correlated to differentiation extent of cancer tissue, metastasis of lymph nodes and histological classification. Thus, alteration of EGFR, TGF-α, P-AKT and PTEN are likely important molecular events in pathogenesis and carcinogenesis of NSCLC.

[Molecular genetic abnormalities of N-myc and C-myc in pediatric neuroblastic tumors and clinical pathologic significance].

OBJECTIVE: To investigate the molecular genetic abnormalities of N-myc and C-myc, and their clinical pathological implications in pediatric neuroblastic tumors (NTs). METHODS: Abnormalities of N-myc were detected by interphase fluorescence in situ hybridization (FISH) technique in 246 cases of NTs, including neuroblastoma (NB,188 cases), ganglioneuroblastoma (GNB, 52 cases), ganglioneuroma (GN, 6 cases), and their association with the histological typing of the tumors and prognosis was analyzed. Abnormalities of C-myc were detected by FISH in 133 cases of NTs. RESULTS: Of the 246 cases of NTs, N-myc amplification was only found in 27 cases (11.0%, 27/246) of NB, but not in any cases of GNB or GN (P < 0.05). 89.0% (219/246) N-myc non-amplification were found in NTs, and it included N-myc gain in 175 cases (71.1%, 175/246) and normal N-myc in 44 cases (17.9%, 44/246). Univariate analysis indicated significantly (P = 0.012) poorer outcome in patients with N-myc amplification than N-myc non-amplification. However no significant difference was observed between N-myc gain cases and normal N-myc cases (P = 0.057). C-myc gain was found in 74 of 133 cases (55.6%) of NTs; no C-myc amplification or translocation was detected. Forty percent (6/15) of cases with N-myc amplification and 57.6% (68/118) of cases with N-myc non-amplification were accompanied by C-myc gain. The difference between N-myc amplification and non-amplification with C-myc gain was not significant (P > 0.05). Univariate analysis indicated that the outcome difference was not statistically significant between C-myc gain cases and normal C-myc cases (P = 0.357). CONCLUSIONS: The incidence of N-myc amplification only found in NB is low in pediatric NTs in China. Patients with N-myc amplification predict poorer outcome. No amplification or translocation of C-myc is detected in NTs, whereas C-myc gain is relatively common in NTs. There is no obvious association between N-myc amplification and C-myc gain.

ALK amplification and protein expression predict inferior prognosis in neuroblastomas.

BACKGROUND: ALK gene has been identified as a major neuroblastoma (NBL) predisposition gene. But ALK gene copy number and protein expression in ganglioneuroblastoma (GNBL) and ganglioneuroma (GN) are poorly described in the literature. Furthermore, there are controversies on the correlation between ALK protein expression and clinical outcome in NBL. METHODS: We evaluated MYCN/ALK gene copy number by fluorescence in situ hybridization (FISH) and detected ALK protein expression by immunohistochemistry (IHC) in 188 NBL, 52 GNBL and 6 GN samples and analyzed their association with clinical outcome of the patients. RESULTS: Although ALK gene copy number increase is a recurrent genetic aberration of neuroblastic tumors (NTs) (39.1%, 96/246), ALK amplification was only present in three NBLs (1.2%, 3/246). The frequency of ALK positivity in NBL (50.5%, 51/101) was significantly higher than in GNBL (22.6%, 7/31) and in GN (0.0%, 0/4) (P<0.05). In addition, ALK positivity also significantly correlates with MYCN/ALK gene copy number increases (P<0.05). Kaplan-Meier survival analysis indicated that MYCN/ALK amplification is correlated with decreased overall survival in NBL. A better prognosis trend was observed in patients with MYCN/ALK gain tumors compared with those with MYCN/ALK normal tumors. Furthermore, ALK positivity significantly correlated with inferior survival in NBL (P=0.044). CONCLUSION: ALK positivity in NTs correlated with advanced tumor types and MYCN/ALK gene copy number increases. ALK positivity predicts inferior prognosis in NBL and IHC is a simplified strategy to screen ALK positivity in clinical practice.

[Vascular cell adhesion molecule-1, eotaxin and vascular endothelial growth factor in nasal polyps after endoscopic surgery].

OBJECTIVE: To study the different expression of VCAM-1, eotaxin and VEGF in nasal polyp tissues and in the nasal mucosa of the operative cavity after endoscopic surgery and its significance. METHODS: Paraffin sections of nasal polyps and the nasal mucosa of the operative cavity were studied with immunohistochemical technique and HE staining. RESULTS: (1) Abundant eosinophils were observed in the nasal polyps, however, it was rarely seen in the nasal mucosa of the operative cavity (t = 2.891, P <0.05). (2) The positive expression of VCAM-1 and eotaxin was in nasal polyps and nasal mucosa of operative cavity, and both of the positive area were not statistically significant (t = - 2.051, P > 0.05), but their average density of light was decreased in the nasal mucosa of the operative cavity (t = 3.670, P = 0.05). The positive glandular of eotaxin were increased after endoscopic surgery (t = -2.899, P < 0.05). (3) Expression of VEGF was similar in both groups (t = - 0.037, 0.825, P > 0.05, respectively). CONCLUSIONS: (1) It is suggested that the nasal mucosa of the operative cavity was different from the nasal polyps. (2) The positive expression of VCAM-1 and eotaxin in the nasal mucosa of the operative cavity after endoscopic surgery indicates that eotaxin may up-regulate the expression of VCAM-1 in vessel endothelium and promote adhesion and migration of eosinophils, as a result, to lead to the recurrence of nasal polyps. The glandulous expression of eotaxin may play a key role in the early stage. (3) The expression of VEGF in nasal mucosa after surgery may contribute to the growth of blood vessel and induce increasing of vascular permeability and tissue edema. This may be an important factor in the process of nasal polyp recurrence.