Expression of phospholipase C isozymes in human breast cancer and their clinical significance.

Phospholipase C (PLC) regulates a number of cellular behaviours including cell motility, cell transformation, differentiation and cell growth. PLC plays a regulatory role in cancer cells partly by acting as signalling intermediates for cytokines such as EGF and interleukins. The current study examined the expression of the PLC isozymes in human breast cancer and corresponding clinical relevance. Transcript levels of human PLC-α, -ß1, -δ, -ε, and -γ1 in human breast cancer tissues were quantitatively determined by real-time PCR. Immunochemical staining was performed for PLC-δ. The clinical relevance was analysed with clinic pathological information. Mammary tissues widely expressed PLC-α, -ß1, -δ, -ε, and -γ1. Significantly high levels of PLC -ß1 and -ε were seen in breast cancer tissues in comparison with normal mammary gland tissues. PLC-γ1 however, showed marginally low levels in tumour tissues. No significant difference was seen in the expression of the PLC isozymes in tumours with lymph node metastases. Moderately and poorly differentiated breast tumours (grade 2 and grade 3) had significantly higher levels of PLC-γ1, compared with well differentiated tumours. High levels of PLC-δ were significantly correlated with a shorter disease-free survival. The altered expression of other isozymes had no correlation with the survival. It is concluded that mammary tissues differentially expressed PLC isozymes. These isozymes have certain implications in the disease development and progression, with PLC-δ showing a significant correlation with shorter disease-free survival.

Psoriasin promotes invasion, aggregation and survival of pancreatic cancer cells; association with disease progression.

Psoriasin (S100A7) is an 11-kDa small calcium binding protein initially isolated from psoriatic skin lesions. It belongs to the S100 family of proteins which play an important role in a range of cell functions including proliferation, differentiation, migration and apoptosis. Aberrant Psoriasin expression has been implicated in a range of cancers and is often associated with poor prognosis. This study examined the role of Psoriasin on pancreatic cancer cell functions and the implication in progression of the disease. Expression of Psoriasin was determined in a cohort of pancreatic tissues comprised of 126 pancreatic tumours and 114 adjacent non-tumour pancreatic tissues. Knockdown and overexpression of Psoriasin in pancreatic cancer cells was performed using specifically constructed plasmids, which either had anti-Psoriasin ribozyme transgene or the full length human Psoriasin coding sequence. Psoriasin knockdown and overexpression was verified using conventional RT-PCR and qPCR. The effect of manipulating Psoriasin expression on pancreatic cancer cell functions was assessed using several in vitro cell function assays. Local invasive pancreatic cancers extended beyond the pancreas expressed higher levels of Psoriasin transcripts compared with the cancers confined to the pancreas. Primary tumours with distant metastases exhibited a reduced expression of Psoriasin. Psoriasin overexpression cell lines exhibited significantly increased growth and migration compared to control cells. In addition, Psoriasin overexpression resulted in increased pancreatic cancer cell invasion which was associated with upregulation of matrix metalloproteinase-2 (MMP-2) and MMP-9. Overexpression of Psoriasin also promoted aggregation and survival of pancreatic cancer cells when they lost anchorage. Taken together, higher expression of Psoriasin was associated with local invasion in pancreatic cancers. Psoriasin expression is associated with pancreatic cancer cell growth, migration, cell-matrix adhesion, and invasion via regulation of MMPs. As such, the proposed implications of Psoriasin in invasion, disease progression and as a potential therapeutic target warrant further investigation.

Reduced NOV expression correlates with disease progression in colorectal cancer and is associated with survival, invasion and chemoresistance of cancer cells.

Aberrant expression of nephroblastoma overexpressed (NOV) has been evident in certain malignancies. In the current study, we aim to investigate the role played by NOV in colorectal cancer (CRC). NOV expression was determined in a cohort of 359 CRC tissues and 174 normal colorectal tissues. Its impact on CRC cells was investigated using in vitro NOV knockdown and overexpression models. NOV transcripts were reduced in the CRC tumours compared with the paired adjacent normal colorectal tissues (p < 0.01) and was associated with distant metastases. NOV knockdown resulted in increased cell proliferation and invasion of RKO cells, whilst an opposite effect was seen in the HT115 NOV over expressing cells. A positive association between Caspase-3/-8 and NOV was seen in NOV knockdown and overexpression cell lines which contributed to the survival of serum deprived CRC cells. Further investigation showed that NOV regulated proliferation, survival and invasion through the JNK pathway. NOV knockdown in RKO cells reduced the responsiveness to 5-Fluorouracil treatment, whilst overexpression in HT115 cells exhibited a contrasting effect. Taken together, NOV is reduced in CRC tumours and this is associated with disease progression. NOV inhibits the proliferation and invasion of CRC cells in vitro. Inhibition of proliferation is mediated by a regulation of Caspase-3/-8, via the JNK pathway, which has potential for predicting and preventing chemoresistance.

Expression of Semaphorin 3C in Breast Cancer and its Impact on Adhesion and Invasion of Breast Cancer Cells.

BACKGROUND: The aim of the current study was to examine the role of semaphorin 3C (SEMA3C) in breast cancer. MATERIALS AND METHODS: SEMA3C transcripts expressed by breast tissues were determined using real-time polymerase chain reaction (PCR). Knock-down of SEMA3C was performed in MDA-MB-231 and MCF-7 breast cancer cell lines using anti-SEMA3C hammerhead ribozyme transgenes. The effect of SEMA3C knockdown on cancer cells was determined using in vitro cellular function assays. RESULTS: Higher SEMA3C transcript levels were significantly associated with poor differentiation of cancer cells, and transcript levels were significantly reduced in oestrogen receptor-positive tumours. Knock-down of SEMA3C expression resulted in a decrease in cell proliferation, adhesion and invasion of breast cancer cells. CONCLUSION: Higher SEMA3C expression is correlated with tumour differentiation. Inhibition of SEMA3C reduces adhesion and invasion of breast cancer cells. This suggests that SEMA3C may play a significant role in morphological changes of cancer cells, leading to enhanced growth and dissemination.

Prostate Apoptosis Response-4 (PAR4) Suppresses Growth and Invasion of Breast Cancer Cells and Is Positively Associated with Patient Survival.

BACKGROUND: Prostate apoptosis response-4 (PAR4) plays an important role in apoptosis and survival of cancer cells. The current study aimed to further elucidate its role in breast cancer. MATERIALS AND METHODS: PAR4 expression in human breast cancer tissue was examined using quantitative polymerase chain reaction (qPCR) and immunohistochemical staining (IHC). Plasmids containing full-length human PAR4 coding sequence were used to overexpress PAR4 in breast cancer cells and the effect on cellular functions was examined using both in vitro functional assays and an in vivo murine model. RESULTS: Patients with low PAR4 transcript levels had poorer overall survival. PAR4 expression may be associated with differential expression of oestrogen receptors α and ß in the tumours. Overexpression of PAR4 in MDA-MB-231 cells resulted in reduced cell growth and invasion, and also reduced in vivo tumour growth. CONCLUSION: Decreased PAR4 expression in breast cancer is associated with shorter survival. PAR4 suppresses growth and invasiveness of breast cancer cells.

Reduced RanBPM Expression Is Associated with Distant Metastasis in Gastric Cancer and Chemoresistance.

AIM: Ran binding protein M (RanBPM) is a ubiquitous, nucleocytoplasmic protein that serves as a scaffolding molecule. This study aimed to investigate the role of RanBPM in gastric cancer. MATERIALS AND METHODS: RanBPM expression in human gastric cancer tissue samples was analyzed using real-time polymerase chain reaction. The effect of RanBPM on cellular functions was examined in RanBPM-knockdown gastric cells and with in vitro cell functional assays. RESULTS: Gastric tumors with distant metastases expressed lower levels of RanBPM transcripts compared to tumours without detectable metastases (p=0.036). RanBPM knockdown in gastric cancer cells reduced adhesion and promoted survival of gastric cancer cells after exposure to methotrexate and fluorouracil. CONCLUSION: RanBPM levels were reduced in gastric tumors with distant metastases. This suggests that loss of RanBPM expression may play an important role in gastric cancer tumor development and metastasis. Reduced RanBPM expression is also associated with chemoresistance of gastric cancer cells.

Routine placement of an intercostal chest drain during video-assisted thoracoscopic surgical lung biopsy unnecessarily prolongs in-hospital length of stay in selected patients.

OBJECTIVE: Video-assisted thoracoscopic surgical (VATS) lung biopsy is frequently used in the diagnosis of parenchymal lung disease. However, there is still debate over the need for routine use of an intercostal chest drain after this procedure. This study aimed to evaluate the necessity of positioning an intercostal chest drain as an integral part of VATS lung biopsy. METHODS: Data from VATS lung biopsies performed over a 5-year period were retrospectively analysed. Patients in whom there was evidence of air leak intra-operatively following lung biopsy were excluded. Patients in whom no air leak was detected on testing were included in this study. A chest drain was inserted solely according to the surgeons' practice. RESULTS: This study included 175 patients. Of these, 82 patients had an intercostal chest drain positioned during the VATS procedure and 93 did not. There were no significant differences between the two groups in terms of mean (standard deviation (SD)), age (54.4 (14.9) vs 55.8 (13.5) years, p=0.58), gender (63% vs 59% males, p=0.56) or side of procedure (45% vs 56% right side, p=0.22). One patient in the 'no drain' group developed a clinically significant pneumothorax 24h after surgery and required a drain to be inserted. There was also no significant difference between the two groups in the incidence of radiologically detected pneumothorax immediately post-procedure (23% vs 20%, p=0.66) or on postoperative day 1 (26% vs 20%, p=0.63). There was no significant difference in the incidence of pneumothorax on follow-up (at 4-6 weeks) chest radiograph (10% vs 7%, p=0.61). In all cases, the pneumothoraces were small and not clinically significant. However, there was a significant difference in the median (inter-quartile range (IQR)) length of stay between the two groups (3 (2,4) vs 2 (1,3) days, respectively, p<0.001). CONCLUSIONS: The routine use of an intercostal chest drain after VATS lung biopsy unnecessarily increases the length of hospital stay without reduction in the incidence of pneumothorax.