High p27 expression is associated with a better prognosis in East Asian non-small cell lung cancer patients

Effect of Statins on Lung Cancer Molecular Pathways: A Possible Therapeutic Role

Lung cancer is a common neoplasm, usually treated through chemotherapy, radiotherapy and/or surgery. Both clinical and experimental studies on cancer cells suggest that some drugs (e.g., statins) have the potential to improve the prognosis of cancer. In fact, statins blocking the enzyme "hydroxy-3-methylglutaryl-coenzyme A reductase" exert pleiotropic effects on different genes involved in the pathogenesis of lung cancer. In this narrative review, we presented the experimental and clinical studies that evaluated the effects of statins on lung cancer and described data on the effectiveness and safety of these compounds. We also evaluated gender differences in the treatment of lung cancer to understand the possibility of personalized therapy based on the modulation of the mevalonate pathway. In conclusion, according to the literature data, statins exert multiple effects on lung cancer cells, even if the evidence for their use in clinical practice is lacking.

The Role of E3 Ligase Pirh2 in Disease

The p53-dependent ubiquitin ligase Pirh2 regulates a number of proteins involved in different cancer-associated processes. Targeting the p53 family proteins, Chk2, p27Kip1, Twist1 and others, Pirh2 participates in such cellular processes as proliferation, cell cycle regulation, apoptosis and cellular migration. Thus, it is not surprising that Pirh2 takes part in the initiation and progression of different diseases and pathologies including but not limited to cancer. In this review, we aimed to summarize the available data on Pirh2 regulation, its protein targets and its role in various diseases and pathological processes, thus making the Pirh2 protein a promising therapeutic target.

PRC1 promotes cell proliferation and cell cycle progression by regulating p21/p27-pRB family molecules and FAK-paxillin pathway in non-small cell lung cancer

Background

This study aimed to demonstrate the function and molecular mechanism of protein regulator of cytokinesis 1 (PRC1) in the carcinogenesis of non-small cell lung cancer (NSCLC).

Methods

Bioinformatics analysis was performed. Cell culture and plasmid construction were conducted for cell transfection. mRNA and protein expression, cell proliferation, migration, and cell cycle were detected. Mice models were also constructed. The relationship between PRC1 and the prognosis of NSCLC patients was analyzed.

Results

PRC1 expression was higher in tumor tissues than adjacent non-tumor tissues (P<0.05). Cells transfected with the high-expression PRC1 plasmid (TOPO-PRC1 group) had the stronger ability of proliferation and migration (P<0.05) along with a lower incidence of stay at the G2/M phase (P<0.05) than the low-expression PRC1 plasmid. Mice models showed tumors obtained from mice in the TOPO-PRC1 group significantly grew faster, larger, and heavier (P<0.05) than the low-expression PRC1 group. Among the 150 NSCLC patients, patients with the higher PRC1 expression were more likely to have lymph node metastasis occur (P<0.05) and progress into an advanced stage (P<0.05), and showed shorter survival (P<0.05). Moreover, the TOPO-PRC1 group had a lower phosphorylation level, and a lower expression of Cip1/p21 (P<0.05) and Kip1/p27 (P<0.01).

Conclusions

PRC1 could promote cell proliferation and cell cycle progression through FAK-paxillin pathway molecules and the regulation of the phosphorylation level of p21/p27-pRB family molecules. PRC1 might be a new and promising therapeutic target for NSCLC.

Suppression of AURKA alleviates p27 inhibition on Bax cleavage and induces more intensive apoptosis in gastric cancer

Bax is a key molecule in mitochondria-apoptosis pathway, however it is not always an efficient apoptosis inducer in chemotherapeutic agents-treated cancer cells. Here, we found that specific inhibition of AURKA by MLN8237-induced calpain-mediated Bax cleavage at N-terminal 33th asparagine (c-Bax) to promote apoptosis. The c-Bax, as Bax, could also efficiently located to mitochondria but c-Bax is a stronger apoptosis inducer than Bax. Morever, c-Bax-induced apoptosis could not be blocked by the canonical Bax inhibitor, Bcl-2. Further study found p27 was degraded and subsequently Bax was transformed to c-Bax through calpain. Also, p27 efficiently inhibited Bax cleavage and p27 knockdown sensitized apoptosis through Bax cleavage when cancer cells were treated with MLN8237. It is also demonstrated that the anti-apoptotic role of p27 lies its cytoplasmic localization. Finally, we found that the positive correlation between AURKA and p27 in advanced gastric cancer patients. In conclusion, we found that MNL8237 suppressed cell growth by regulating calpain-dependent Bax cleavage and p27 dysregulation in gastric cancer cells.

Clinical significances of p27 in digestive tract cancers: a comprehensive analysis on immunohistochemistry staining, published literatures, microarray and RNA-seq data

In the present study, we conducted a comprehensive analysis on the clinical roles of p27 protein and p27 gene in digestive tract cancers (DTCs). First, we performed immunohistochemistry staining and found that p27 protein was down-regulated in DTCs. Then we collected 62 publications and calculated the combined hazard ratios (HRs), odds ratios (ORs) and 95% confidence intervals (95% CIs) to clarify the relationships of p27 protein expression with prognoses and clinicopathological parameters. The overall HRs indicated that the down-regulated p27 protein was an independent prognostic biomarker for overall survival (HR: 1.58, 95% CI: 1.38-1.81, P < 0.0001) but not for disease-free survival and cancer-specific survival. The combined ORs indicated that a low expression of p27 protein was positively related to lymph node metastasis (OR: 2.15, 95% CI: 1.57-2.96, P < 0.0001), distant metastasis (OR: 2.02, 95% CI: 1.12-3.63, P = 0.019) and pathology grading (OR: 2.14, 95% CI: 1.75-2.62, P < 0.0001). Additionally, 60 DTCs-related microarray and RNA-seq datasets were obtained to investigate the expression level and clinical value of p27 gene in DTCs patients. We found that the expression level of p27 gene in DTCs was similar to that in normal controls. And no significant associations of p27 gene expression with prognoses and clinicopathological factors were observed. In conclusion, according to our results, it was p27 protein, but not p27 gene, that can function as an effective biomarker to predict the clinical outcome in patients with DTCs. The down-regulation of p27 protein in DTCs may not result from the altered expression of p27 gene.

Clinicopathological and Prognostic Significance of p27 Expression in Oral Squamous Cell Carcinoma: A Meta-Analysis

Despite being already known that p27 can regulate cell proliferation, cell motility and apoptosis, the role of p27 expression in oral squamous cell carcinoma (OSCC) remains controversial. The purpose of this study was to comprehensively evaluate, with a meta-analysis, the clinicopathological and prognostic role of p27 expression in OSCC. A meta-analysis of eligible studies was performed to assess the effects of p27 expression on clinicopathological parameters and overall survival (OS) in patients with OSCC, using pooled relative risks with 95% confidence intervals. Heterogeneity and publication bias were also assessed. Fourteen studies involving a total of 1,010 patients met the inclusion criteria. Low p27 expression was significantly associated with advanced TNM stage (p<0.001), worse histology (p=0.025), and lymph node metastasis (p<0.001), but not with tumor size (p=0.181). The pooled RR of 0.743 (p=0.002) suggested that low p27 expression has a poor prognosis in patients with OSCC. A significant heterogeneity among studies was detected for lymph node status (χ2=34.60, I2=68.2%, p<0.001) and OS (χ2=14.86, I2=39.4%, p=0.095). We did not detect a significant publication bias in this meta-analysis. Our meta-analysis suggests that p27 expression status might be useful as a predictive biomarker in clinical practice, and might potently predict OS in OSCC patients.

Long-term G1 cell cycle arrest in cervical cancer cells induced by co-immobilized TNF-α plus IFN-γ polymeric drugs

A realistic control of cell cycle arrest is an attractive goal for the development of new effective anti-cancer drugs. Any clinical application of an effective anti-cancer drug necessarily relies on the understanding of cellular interaction mechanisms. In the present study, we prepared a co-immobilized TNF-α plus IFN-γ biomaterial, which showed a significant inhibition effect on cervical cancer cell growth, as demonstrated by a series of structural and cellular characterizations. We found that co-immobilized TNF-α plus IFN-α induced a long-term G₁ phase cell cycle arrest in HeLa, SiHa, and CaSki cells, respectively. More surprisingly, the expression level of the p27 protein decreased, even when p27 mRNA was highly expressed. In addition, gene-chip results and microarray analysis showed that p57 may be downstream from p27, which acts as a direct regulator of the long-term G₁ cell cycle arrest in these cells, leaving no escape for cervical cancer cells. Finally, we also investigated the anti-tumor mechanism of co-immobilized TNF-α plus IFN-γin vivo, using a nude mice animal model. To sum up, our findings suggested that the co-immobilized TNF-α plus IFN-γ can induce a long-term cell cycle arrest in cancer, thus serving as a very efficient tool for treating cervical cancer.

Functional characterization of AMP-activated protein kinase signaling in tumorigenesis

AMP-activated protein kinase (AMPK) is a ubiquitously expressed metabolic sensor among various species. Specifically, cellular AMPK is phosphorylated and activated under certain stressful conditions, such as energy deprivation, in turn to activate diversified downstream substrates to modulate the adaptive changes and maintain metabolic homeostasis. Recently, emerging evidences have implicated the potential roles of AMPK signaling in tumor initiation and progression. Nevertheless, a comprehensive description on such topic is still in scarcity, especially in combination of its biochemical features with mouse modeling results to elucidate the physiological role of AMPK signaling in tumorigenesis. Hence, we performed this thorough review by summarizing the tumorigenic role of each component along the AMPK signaling, comprising of both its upstream and downstream effectors. Moreover, their functional interplay with the AMPK heterotrimer and exclusive efficacies in carcinogenesis were chiefly explained among genetically altered mice models. Importantly, the pharmaceutical investigations of AMPK relevant medications have also been highlighted. In summary, in this review, we not only elucidate the potential functions of AMPK signaling pathway in governing tumorigenesis, but also potentiate the future targeted strategy aiming for better treatment of aberrant metabolism-associated diseases, including cancer.

Low Expression of CDK5 and p27 Are Associated with Poor Prognosis in Patients with Gastric Cancer

Several previous studies have demonstrated that CDK5 or p27 expression in gastric cancer are associated with overall survival. We have previously reported that tumor suppressive function of CDK5 is related to p27. The aim of this study was to investigate correlation between the clinicopathological parameters and overall survival with different CDK5/p27 expression statuses in 244 gastric cancer patients using immunohistochemistry. Low CDK5 expression was detected in 93 cases (38.11%) and low p27 in 157 cases (64.34%). The expression of CDK5 was significantly related to sex (P = 0.034) and Lauren's classification (P = 0.013). The expression of p27 was significantly related to sex (P = 0.012), differentiation (P = 0.003), TNM stage (P = 0.013) and lymph node metastasis (P = 0.001). Based on the combined expression of CDK5 and p27, we classified the patients into four subtypes: CDK5 Low/p27 Low (n = 69), CDK5 High/p27 Low (n = 88), CDK5 Low/p27 High (n = 24) and CDK5 High/p27 High (n = 63). The CDK5 Low/p27 Low expression was closely related to female (P = 0.026), diffuse type (P = 0.027) and lymph node metastasis (P = 0.010). The CDK5 Low/p27 Low patients displayed poorer survival in comparison with the rest of the patients in Kaplan-Meier analysis. No significant overall survival difference was observed among the patients with CDK5 High and/or p27 High expression. In the multivariate analysis, CDK5 and p27 co-expression status was identified as an independent prognostic factor for patients with gastric cancer.

Association of cytoplasmic p27 expression with an unfavorable response to cisplatin-based chemotherapy and poor outcomes in non-small cell lung cancer

Reduced nuclear p27 expression is associated with a poor outcome in various cancers, including non-small cell lung cancer (NSCLC). Cytoplasmic p27 expression was shown to be associated with an unfavorable response to chemotherapy and poor outcomes in some carcinomas, but it has not been well studied in NSCLC. Herein, p27 expression in 219 tumors surgically resected from NSCLC patients was evaluated by immunohistochemistry (IHC). The most common of p27 immunostaining in lung tumors was observed in the cytoplasm (N-/C+, 32 %), followed by negative (N-/C-, 29 %), nucleus (N+/C-, 24 %), and nucleus plus cytoplasm (N+/C+, 15 %). Kaplan-Meier and Cox regression models showed that p27 N-/C+ tumors exhibited the worst overall survival (OS) and relapse-free survival (RFS) among the four categories of tumors. Among 135 of 219 patients who received cisplatin-based chemotherapy, p27 N-/C+ tumors most commonly showed an unfavorable response to cisplatin-based chemotherapy, followed by p27 N-/C- tumors when p27 N+/C- tumors were used as a reference. IHC analysis for phosphorylated extracellular signal-regulated kinase (p-ERK) and Bcl-2 expression in the lung tumors was performed to test whether ERK activation could enhance p27 nuclear export and the expression of Bcl-2 to test whether ERK activation could enhance p27 nuclear export and Bcl-2 expression. The data showed that p-ERK expression was positively correlated with cytoplasmic p27 (N-/C+) and Bcl-2 expression in the lung tumors. Patients with high Bcl-2-expressing tumors treated with cisplatin-based chemotherapy showed unfavorable predictive values in a subset of this study population. Therefore, we suggest that cytoplasmic p27 (N-/C+) via ERK-activated Bcl-2 expression may predict an unfavorable response to cisplatin-based chemotherapy and poor outcomes in NSCLC.

p27Kip1 expression as a prognostic marker for squamous cell carcinoma of the head and neck

Regulation of the cell cycle is essential for carcinogenesis. The cell cycle is controlled by cyclin-dependent kinases (CDKs), which are upregulated by cyclins and downregulated by CDK inhibitors (CDKIs). Decreased p27^Kip1 expression has been associated with survival rate, tumor size, histological differentiation and the presence of lymph node metastasis in patients with various types of cancer. The aim of the current study is to provide a literature review on the association between p27^Kip1 expression and the clinical and pathological aspects of head and neck squamous cell carcinoma (HNSCC), and the expression of other CDKIs of the Cip/Kip family and cyclins. Throughout the literature, different methodologies were used to determine the immunohistochemical expression of p27^Kip1; thus, results concerning p27^Kip1 expression in HNSCC vary widely. However, it has now been confirmed that p27^Kip1 is underexpressed in SCC cells. p27 may be a promising marker for determining the prognosis of HNSCC, despite the marked variability of the results obtained. An association between p27 expression and survival rate, time to recurrence and tumor stage has been observed. Based on the information currently available, it is premature to recommend the analysis of p27^Kip1 expression in guiding HNSCC treatment planning. However, although relatively unstudied, the correlation between p27^Kip1 expression and other tumor suppressor genes may turn out to be important in determining the prognosis of HNSCC. Further prospective studies utilizing standardized laboratory methodologies and statistics that facilitate meta-analyses are required to confirm this proposal.

The novel protective role of P27 in MLN4924-treated gastric cancer cells

The tumor-suppressor gene cyclin-dependent kinase inhibitor 1B (P27) is downregulated in gastric cancer cells mainly through proteolytic degradation mediated by the SKP-Cullin1-F-Box (SCF) complex. But the correlation between its downregulation and gastric cancer prognosis still remains indefinite. MLN4924, an anti-tumor agent, which suppresses the SCF complex by inhibiting Cullin1 neddylation, emerges as a promising tool to elucidate its functions in gastric cancer cells. In this study, MLN4924 induced significant growth inhibition of gastric cancer cells in a dose-dependent manner, along with the simultaneous accumulation of P27 and cell cycle abnormalities such as G2/M arrest. Importantly, we found that P27 silencing in MLN4924-treated cells resulted in an enhancement of growth inhibition both in vitro and in vivo. Mechanism analysis revealed the antagonism effects of antioxidants to this excess apoptosis, suggesting reactive oxygen species (ROS) overproduction especially in the mitochondria was the principal cause of the augmentation. Moreover, the robust ROS attacked the mitochondria to initiate collapse of the mitochondrial membrane permeability and the exportation of apoptosis-inducing factor (AIF), IAP-binding mitochondrial protein (SMAC/DIABLO) and cytochrome c. Finally, we also found that P27 knockdown affected the expression profile of several critical BH3 family members to amplify the mitochondrial dysfunction and apoptosis. In summary, our findings unveiled a protective role of P27 by maintaining mitochondrial membrane permeability in MLN4924-treated gastric cancer cells, and therefore highlighted the potential combination of MLN4924 with P27 inhibition to improve its therapeutic efficacy.

A novel differential diagnostic model for multiple primary lung cancer: Differentially-expressed gene analysis of multiple primary lung cancer and intrapulmonary metastasis

The incidence of synchronous multiple primary lung cancer (MPLC) is increasing. However, present diagnostic methods are unable to satisfy the individualized treatment requirements of patients with MPLC. The present study aimed to establish a quantitative mathematical model and analyze its diagnostic value for distinguishing between MPLC and cases of the histologically similar disease, intrapulmonary metastasis (IPM). The sum value of the differential expression ratios of four proteins, namely p53, p16, p27 and c-erbB2, was evaluated by immunohistochemically-staining specimens of primary cancers, second separate cancers, metastatic lymph nodes and metastatic cancers. The sum value of the differential expression ratio of the four proteins from the primary tumor and the lymph-node metastasis or metastatic cancer was <90 in the 11 patients with a single metastatic cancer and in the 30 patients with lymph-node metastasis, but was >90 in the 14 patients with different histological types of MPLC. Therefore, a quantitative differentially-expressed gene mathematical model was established as follows: Sum of the differential expression ratios = p16T1 - T + p27T1 - T2 + C-erbB2T1 - T2 + p53T1 - T2, where T1 is the primary cancer and T2 is the lymph node metastasis, metastatic cancer or the second separate cancer. The quantitative differentially-expressed gene mathematical model is considered to be a useful tool for distinguishing between MPLC and IPM.

Expression of cell cycle regulatory proteins in eyelid sebaceous gland carcinoma: low p27 expression predicts poor prognosis

Prognosis of eyelid sebaceous gland carcinoma is largely unpredictable and there are few practically available markers for predicting patients' prognosis. Dysregulation of cell cycle progression is strongly associated with the development of cancer and the cancer prognosis. We investigated the expression of cell cycle regulatory proteins in eyelid sebaceous gland carcinoma and estimate their value as prognostic predictors. Forty-three cases of eyelid sebaceous gland carcinoma were included in this study. Immunohistochemistry for the p53, p21, p27, cyclin E, p16, cyclin D1, and phosphorylated Rb (pRb) proteins was performed using archival paraffin blocks. Correlations between clinical features and protein expression were evaluated statistically. Nine patients showed lymph node or distant metastasis, and the remaining patients showed localized disease. High expression of p21, p27, cyclin E, and p16 was found in the majority of tumor cell nuclei, whereas these proteins were rarely expressed in the normal sebaceous glands. However, pRb was focally lost in a subset of cases. Patients showing diffuse p27 expression developed metastasis less commonly than those with negative or focal p27 expression (log-rank test, p = 0.008). Aberrant expression of cell cycle regulatory proteins was observed in eyelid sebaceous gland carcinoma, suggesting that cell cycle dysregulation is involved in the pathogenesis of this tumor. Decreased p27 expression is a predictive biomarker of an unfavorable prognosis of eyelid sebaceous gland carcinoma.

Skp2-RNAi suppresses proliferation and migration of gallbladder carcinoma cells by enhancing p27 expression

AIM: To explore the role of S-phase kinase-associated protein-2 (Skp2) in gallbladder carcinoma and to identify whether depletion of Skp2 by Skp2-RNAi could attenuate proliferation and migration of gallbladder carcinoma.

METHODS: Skp2-RNAi was transduced into cells of the gallbladder carcinoma cell line GBC-SD, using a lentiviral vector. The effect of Skp2-RNAi on the proliferation, migration, invasion and cell cycle of GBC-SD cells was studied using in vitro assays for cell proliferation, colony formation, wound healing and cell cycle. The expression of Skp2 and p27 was detected by real-time polymerase chain reaction and Western immunoblotting. The effect of Skp2-RNAi on the proliferation of GBC-SD cells in vivo was investigated by tumorigenicity experiments in nude mice.

RESULTS: Lentivirus-mediated RNAi reduced the expression of Skp2 in cultured cells. The expression of the p27 protein increased along with the down-regulation of Skp2, although no significant difference was found in p27 mRNA expression. Flow cytometry revealed that Skp2-RNAi transfection significantly increased the proportion of cells in the S phase and significantly decreased the proportion of cells in the G₂/M phase. No significant difference in the frequency of cells in the G₀/G₁ phase was observed. The results from the cell proliferation, colony formation and wound healing assays revealed that Skp2-RNAi transfection markedly inhibited the proliferation and migration of GBC-SD cells in vitro. Additionally, tumorigenicity experiments showed that suppression of Skp2 significantly decreased the weights of the tumors (0.56 ± 0.11 and 0.55 ± 0.07 g in the control and Scr-RNAi groups vs 0.37 ± 0.09 and 0.35 ± 0.08 g in the Skp2-RNAi-L and Skp2-RNAi-H groups).

CONCLUSION: The expression of Skp2 in GBC-SD cells was inhibited following Skp2-RNAi transfection. Silencing of the Skp2 gene inhibited proliferation, migration and invasiveness of GBC-SD cells by mechanisms dependent on enhanced expression of the p27 protein.

Beneficial role of overexpression of TFPI-2 on tumour progression in human small cell lung cancer

Tissue factor pathway inhibitor-2 (TFPI-2) is a potent inhibitor of plasmin, a protease which is involved in tumour progression by activating (MMPs). This therefore makes TFPI-2 a potential inhibitor of invasiveness and the development of metastases. In this study, low levels of TFPI-2 expression were found in 65% of patients with small cell lung cancer (SCLC), the most aggressive type of lung cancer. To study the impact of TFPI-2 in tumour progression, TFPI-2 was overexpressed in NCI-H209 SCLC cells which were orthotopically implanted in nude mice. Investigations showed that TFPI-2 inhibited lung tumour growth. Such inhibition could be explained in vitro by a decrease in tumour cell viability, blockade of G1/S phase cell cycle transition and an increase in apoptosis shown in NCI-H209 cells expressing TFPI-2. We also demonstrated that TFPI-2 upregulation in NCI-H209 cells decreased MMP expression, particularly by downregulating MMP-1 and MMP-3. Moreover, TFPI-2 inhibited phosphorylation of the MAPK signalling pathway proteins involved in the induction of MMP transcripts, among which MMP-1 was predominant in SCLC tissues and was inversely expressed with TFPI-2 in 35% of cases. These results suggest that downregulation of TFPI-2 expression could favour the development of SCLC.

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The Tissue Factor Pathway Inhibitor-2 inhibits small cell lung cancer growth

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Monitoring of small cell lung cancer growth in a mouse orthotopic model by imaging

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Increasing information on the role of TFPI-2 in human lung tumour cells

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Increasing information on TFPI-2 and protease expression in human tissue samples

Prognostic significance of p21, p27 and survivin protein expression in patients with oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) accounts for >80% of head and neck malignancies. p21, p27 and survivin proteins are abnormally expressed in OSCC and have been previously reported to correlate with cell proliferation and apoptosis. However, the prognostic significance of p21, p27 and survivin remains controversial. The aim of the present study was to investigate the association of clinical parameters and prognosis with the levels of p21, p27 and survivin expression in patients with OSCC. The levels of the three biomarkers were evaluated by immunohistochemical staining in specimens from 110 patients with OSCC and each section was scored according to the percentage of positive tumor cells and staining intensity. Log-rank test and Cox proportional hazards regression were performed to assess the correlation between biomarkers and clinical events. The association between the immunoexpression of p21, p27 and survivin and clinical pathological variables were analyzed by the χ² test and a non-parametric analysis. The expression of p21 in patients with OSCC was found to correlate with the expression of p27 and survivin. The results of the current study revealed that the five-year survival rate was significantly lower in patients with high p21 expression. In addition, the expression of p27 also showed a negative correlation with the five-year survival rate of OSCC, but to a lesser extent. By contrast, the expression of survivin was not a prognostic factor for OSCC. A Kaplan-Meier analysis and Cox proportional hazards model showed that lymph node metastasis and p21 expression were independent prognostic factors of OSCC.

2-Amino-1,3,4-thiadiazole derivative (FABT) inhibits the extracellular signal-regulated kinase pathway and induces cell cycle arrest in human non-small lung carcinoma cells

The anticancer potential of 2-amino-1,3,4-thiadiazole compounds has been documented by in vitro and in vivo studies. In our previous research, we described the synthesis as well as the antiproliferative and neuroprotective activities of 2-(4-fluorophenyloamino)-5-(2,4-dihydroxyphenyl)-1,3,4-thiadiazole (FABT). The aim of the present study was to investigate the molecular mechanisms involved in FABT-induced growth inhibition in A549 lung carcinoma cells. Western blotting analysis revealed that FABT inhibited the activation of the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway, and Real-time PCR analysis showed no changes in the expression of P44ERK1 and CREB1 genes. Furthermore, FABT induced cell cycle arrest in the GO/G1 phase and enhanced p27/Kip1 expression. Our results suggest that FABT acts by inhibiting ERK1/2 pathway and cell cycle progression through G1 into S phase in A549 cells. Further studies are needed to completely explain the molecular mechanisms of anticancer action of this 2-aminothiadiazole derivative.

Prognostic value of matrix metalloproteinase 9 expression in patients with non-small cell lung cancer

BACKGROUND

The role of matrix metalloproteinase 9 (MMP-9) expression in non-small cell lung cancer (NSCLC) remains controversial. We performed a systematic review of the literature with meta-analysis.

METHODS

Electronic databases were used to identify published studies before December 1, 2011. Pooled hazard ratio (HR) with 95% confidence interval (95% CI) was used to estimate the strength of the association between MMP-9 expression survival of NSCLC patients. Heterogeneity and publication bias were also assessed.

RESULTS

The final analysis of 2029 NSCLC cases from 17 studies is presented. The combined HR of 1.84 (95% CI: 1.62-2.09) suggested that MMP-9 over-expression had a poor prognosis in patients with NSCLC. Subgroup analyses also detected significant association. Heterogeneity and publication bias was absent in current meta-analysis. Sensitivity analyses suggested that the summary statistics obtained should approximate the actual average.

CONCLUSION

High MMP-9 expression is associated with a poor prognosis in patients with NSCLC.

Meta-analysis for cyclin E in lung cancer survival

BACKGROUND

To assess the prognosis value of cyclin E expression in survival of patients with lung cancer (LC), we performed a systematic review of the literature with meta-analysis.

METHODS

Electronic databases were used to identify published studies before August 2011. Pooled hazard ratio (HR) with 95% confidence interval (95% CI) was used to estimate the strength of the association of cyclin E expression with survival of LC patients. Heterogeneity and publication bias were also assessed.

RESULTS

Fourteen studies (2606 cases) were eligible and subjected to analysis. Cyclin E over-expression was found to be a strong predictor of poor prognosis in LC patients (HR: 1.38, 95% CI: 1.07-1.79; P=0.014). When only non-small cell lung cancer (NSCLC) was considered, the combined HR was 1.53 (95% CI: 1.19-1.97, P=0.001). A significant association was also evident when the analysis was limited to studies involving adenocarcinoma (AD), but not squamous cell carcinoma (SQ). Publication bias was absent. Sensitivity analyses suggested that the summary statistics obtained should approximate the actual average.