MicroRNA-561 Affects Proliferation and Cell Cycle Transition Through PTEN/AKT Signaling Pathway by Targeting P-REX2a in NSCLC

MicroRNAs (miRNAs) play crucial roles in tumorigenesis and tumor progression. miR-561 has been reported to be downregulated in gastric cancer and affects cancer cell proliferation and metastasis. However, the role and underlying molecular mechanism of miR-561 in human non-small cell lung cancer (NSCLC) remain unknown and need to be further elucidated. In this study, we discovered that miR-561 expression was downregulated in human NSCLC tissues and cell lines. The overexpression of miR-561 inhibited NSCLC cell proliferation and cell cycle G₁/S transition and induced apoptosis. The inhibition of miR-561 facilitated cell proliferation and G₁/S transition and suppressed apoptosis. miR-561 expression was inversely correlated with P-REX2a expression in NSCLC tissues. P-REX2a was confirmed to be a direct target of miR-561 using a luciferase reporter assay. The overexpression of miR-561 decreased P-REX2a expression, and the suppression of miR-561 increased P-REX2a expression. Particularly, P-REX2a silencing recapitulated the cellular and molecular effects observed upon miR-561 overexpression, and P-REX2a overexpression counteracted the effects of miR-561 overexpression on NSCLC cells. Moreover, both exogenous expression of miR-561 and silencing of P-REX2a resulted in suppression of the PTEN/AKT signaling pathway. Our study demonstrates that miR-561 inhibits NSCLC cell proliferation and G₁/S transition and induces apoptosis through suppression of the PTEN/AKT signaling pathway by targeting P-REX2a. These findings indicate that miR-561 plays a significant role in NSCLC progression and serves as a potential therapeutic target for NSCLC.

Clinicopathological and prognostic significance of pretreatment thrombocytosis in patients with endometrial cancer: a meta-analysis

Background: The prognostic and clinicopathological role of pretreatment thrombocytosis in cancer has been widely studied, but conclusions in endometrial cancer (EnCa) remain controversial. Therefore, we conducted a meta-analysis to assess the pathologic and prognostic impacts of pretreatment thrombocytosis in patients with EnCa. Methods: We searched PubMed, Embase, SpringerLink, ScienceDirect and China National Knowledge Infrastructure databases. Pooled HR or OR with their 95% CIs were applied to assess the association of pretreatment thrombocytosis with survival outcomes and clinical parameters of EnCa patients. Results: In total, 10 studies containing 2,995 cases of EnCa met the criteria. The results suggested that pretreatment thrombocytosis was significantly associated with high International Federation of Gynecology and Obstetrics (FIGO) stage (pooled OR 3.45, 95% CI 1.68-7.08, P=0.001), poor tumor differentiation (pooled OR 2.00, 95% CI 1.22-3.29, P=0.006), lymph-vascular space invasion (pooled OR 2.04, 95% CI 1.35-3.07, P=0.001); myometrial invasion (pooled OR 2.14, 95% CI 1.39-3.32, P=0.001); cervical involvement (pooled OR 2.54, 95% CI 1.56-4.15, P=0.000) and lymph node metastasis (OR 3.15, 95% CI 1.71-5.80, P=0.001). No significant difference existed between pretreatment thrombocytosis and overall survival (P=0.012), cancer/disease-specific survival (P=0.07) or disease-free survival (P=0.25). Conclusion: pretreatment thrombocytosis was associated with advanced clinicopathological features in patients with EnCa, which may serve as a potential therapeutic target for EnCa.

P57-mediated autophagy promotes the efficacy of EGFR inhibitors in hepatocellular carcinoma

BACKGROUND & AIMS

Resistance to EGFR-targeted therapy is a major obstacle in hepatocellular carcinoma (HCC) treatment, but its underlying mechanism remains unclear. Autophagy plays a vital role in antitumour treatment. Our previous study suggested that p57 is associated with autophagy and cisplatin resistance. The present study aimed to investigate whether p57 can enhance the sensitivity of HCC cells to Erlotinib (Er)/Cetuximab(C-225) and further explore the potential mechanisms of Er/C-225 resistance.

METHODS

HCC cells were transfected with pIRES2-EGFP-p57 and pIRES2-EGFP-nc, accompanied by Er/C-225 treatment. Cell viability was detected by an Annexin apoptosis kit and MTT assay. Xenograft experiments were performed to study the function of p57 in the treatment of Er/C-225 in vivo. The level of autophagy was determined by analysis of the appearance of autophagic vacuoles. Western blotting was used to investigate the potential pathways involved.

RESULTS

Up-regulation of p57 decreased the level of Er/C-225-induced autophagy and enhanced the decrease in Er/C-225-induced cell viability. P57 overexpression combined with CQ treatment further enhanced the therapeutic efficiency of Er/C-225. The xenograft experiment verified that p57 up-regulation sensitizes HCC cells to Er/C-225. Moreover, a mechanistic investigation demonstrated that the up-regulation of p57 resulted in a decrease of LC3B-II and beclin-1, and an increase in p-PI3K, p-AKT and p-mTOR protein expressions.

CONCLUSIONS

Through activating the PI3K/AKT/mTOR signalling pathway, p57 can reverse Er/C-225-induced autophagy, and thereby increase the therapeutic efficiency of Er/C-225 treatment. Given these results, p57 up-regulation may be applicable as a therapeutic strategy to improve EGFR-targeted therapy in HCC.

Expression and clinical significance of autophagic protein LC3B and EMT markers in gastric cancer

Background and aim

Gastric cancer (GC) is a fatal malignancy with high rate of recurrence and metastasis. Here, we investigated the correlations between the expression of autophagic protein LC3B and 2 epithelial–mesenchymal transition-related proteins (E-cadherin and Vimentin) and the clinicopathological factors and prognosis of patients with GC.

Materials and methods

The expression of LC3B, E-cadherin, and Vimentin in GC samples (110 cases) and paracarcinoma tissues (40 cases) was analyzed using the Oncomine databases and further detected by immunohistochemistry. The correlations among these markers expression and clinicopathological features in GC were analyzed. The patients were followed for survival analysis.

Results

Compared to the nontumor tissues, the expression of LC3B and Vimentin proteins were significantly elevated in GC tissues, but the E-cadherin expression was decreased (all p<0.05). Interestingly, LCB expression was positively correlated with Vimentin (r=0.320, p=0.001) and negatively associated with E-cadherin expression (r= −0.484, p<0.001) in GC. The expression of these markers was closely related to tumor differentiation, T classification, TNM stage, and lymph node metastasis (all p<0.05). Furthermore, survival analyses and screening Kaplan–Meier plotter database revealed that GC patients with high LC3B and Vimentin expression levels had a poorer clinical outcome than those with low expression. Conversely, high E-cadherin expression was linked with favorable overall survival (all p<0.05, log-rank test). Multivariate survival analysis demonstrated that LC3B, E-cadherin, and Vimentin expression were independent prognostic factors of GC patients.

Conclusion

LC3B, E-cadherin, and Vimentin may play an important role in the tumorigenesis of GC, and these marker expressions may serve as additional prognostic indicators for overall survival of patients. The interactions of autophagy and epithelial–mesenchymal transition in GC merits further investigation.

Combination of S-1 and gefitinib increases the sensitivity to radiotherapy in lung cancer cells

OBJECTIVE

To investigate the potential radiosensitization of S-1 and gefitinib in human non-small cell lung cancer (NSCLC) in vitro and in vivo.

METHODS

The impact of radiation, 5-fluorouracil (5-Fu), and gefitinib on the proliferation and apoptosis of human NSCLC A549, H1299, H1975, and HCC827 cells was examined by MTT and flow cytometry. The effect of radiation, 5-Fu, and gefitinib on the clonogenicity of H1975 and HCC827 cells was determined by colony formation assay. The effect of radiation, 5-fluorouracil (5-Fu), and gefitinib on the EGFR, AKT, and ERK1/2 activation in H1975 cells was determined by Western blot. The therapeutic efficacy of radiation, S-1, and gefitinib in the growth of implanted H1975 tumors and the AKT activation in the tumors were examined in vivo and immunohistochemistry, respectively.

RESULTS

Combination of radiation, 5-Fu, and gefitinib significantly inhibited the proliferation of H1975 cells and triggered their apoptosis, but not other NSCLC cells tested. The combination therapy significantly mitigated the clonogenicity and attenuated the activation of EGFR and AKT signaling in H1975 cells. Furthermore, combination of S-1, gefitinib, and radiation significantly inhibited the growth of implanted H1975 tumors in mice and remarkably reduced the AKT phosphorylation in the tumors.

CONCLUSIONS

Our data indicated that combination of S-1 and gefitinib significantly increased radiosensitivity of H1975 cells. The triple combination therapies may benefit patients with the EGFR T790M mutant NSCLC.

Surgical resection improves long-term survival of patients with hepatocellular carcinoma across different Barcelona Clinic Liver Cancer stages

Objectives

Surgical resection remains a controversial treatment for hepatocellular carcinoma (HCC) within different Barcelona Clinic Liver Cancer (BCLC) stages. The objective of this study was to evaluate the long-term outcome of patients undergoing surgical resection (SR) compared to non-surgical treatments across different BCLC stages.

Patients and methods

One thousand four hundred forty-three HCC patients within BCLC 0, A, B and C stages were identified. Overall survival was compared by log-rank test among patients within different BCLC stages and among patients receiving different treatments (SR vs locoregional therapy [LRT] vs best supportive care). Propensity score matching analysis was introduced to mitigate the confounding biases between the groups.

Results

The median survival time of the patients diminished from early, intermediate to advanced BCLC stages (BCLC 0-A 43 [range 0-100] months vs BCLC B 32 [range 0-100] months vs BCLC C 27 [range 0-90] months, all p<0.05). Patients undergoing SR presented with better liver function and more favorable tumor status and, consequently, displayed significant better overall survival than patients receiving LRT or best supportive care at different BCLC stages. In adjusted cohort after propensity score matching, patients who were surgically treated consistently had more favorable outcome than those who were non-curatively treated across different BCLC stages (median survival [range]: BCLC stage B: resection 45 [0-100] months vs LRT 36 [0-81] months, p=0.002; BCLC stage C: resection 39 [3-77] months vs LRT 27 [0-54] months, p=0.003).

Conclusion

Surgical resection should be considered as a radical treatment for selected HCC patients regardless of the BCLC stages when appropriate.

β1 integrin-mediated multicellular resistance in hepatocellular carcinoma through activation of the FAK/Akt pathway

Objective

To explore the role and mechanism of β1 integrin in the regulation of multicellular drug resistance in hepatocellular carcinoma (HCC).

Methods

This in vitro study used a liquid overlay technique to obtain multicellular spheroids of two human HCC cell lines, HepG2 and Bel-7402. The morphology of the spheroids was observed by optical and electron microscopy. The effects of exposure to 5-fluorouracil (5-FU) and cisplatin (CDDP) on cell proliferation and the induction of apoptosis were assessed in monolayer cells and multicellular spheroids. The levels of β1 integrin and the effects on the focal adhesion kinase (FAK)/protein kinase B (Akt) pathway were evaluated using Western blot analysis, immunofluorescence and flow cytometry. The role of β1 integrin was confirmed by using an inhibitory antibody.

Results

Cell proliferation inhibition and cell apoptosis induced by 5-FUl and CDDP were abrogated in multicellular spheroids compared with monolayer cells. There were high levels of β1 integrin in multicellular spheroids. β1 integrin inhibitory antibody prevented the formation of multicellular spheroids, coupled with a significant increase in proliferation inhibition and apoptosis induction. β1 integrin inhibitory antibody effectively suppressed activation of both FAK and Akt in multicellular spheroids.

Conclusions

β1 integrin mediated multicellular drug resistance through the FAK/Akt pathway in HCC spheroids.

Delisheng induces antiproliferation and apoptosis effects in Hep3B cells via modulation of angiogenic proteins

Delisheng is a widely used antineoplastic agent in China. Although previous studies revealed that Delisheng exhibits numerous pharmacological effects including the inhibition of cancer cell differentiation and enhancement of immune function with the lowest toxicity, the precise anticancer mechanisms of Delisheng in human hepatocellular carcinoma (HCC) cells remains largely unknown. The present study investigated the potential mechanisms underlying the anticancer properties of Delisheng on Hep3B cells. Delisheng demonstrated a strong anti-proliferation effect on Hep3B cells compared with normal liver HL-7702 cells, as detected by MTT assays. In addition, Delisheng arrested the cells in G/G₁ phase. Furthermore, it exhibited a pro-apoptotic effect on Hep3B cells, as detected by flow cytometry. When exposed to Delisheng, Hep3B cells demonstrated decreased vascular endothelial growth factor (VEGF) and osteopontin (OPN) and increased endostatin (ES) protein expressions, as detected using immunocytochemistry staining and western blotting. These data suggest that Delisheng induces antiproliferation and apoptosis of Hep3B cells via modulation of VEGF, OPN and ES protein expression. It is hypothesized that Delisheng may be used as a novel anticancer therapeutic in HCC.

The clinical use of the platelet/lymphocyte ratio and lymphocyte/monocyte ratio as prognostic predictors in colorectal cancer: a meta-analysis

BACKGROUND

Conflicting evidence exists regarding the effects of platelet/lymphocyte ratio (PLR) and lymphocyte/monocyte ratio(LMR) on the prognosis of colorectal cancer (CRC) patients. This study aimed to evaluate the roles of the PLR and LMR in predicting the prognosis of CRC patients via meta-analysis.

METHODS

Eligible studies were retrieved from the PubMed, Embase,andChina National Knowledge Infrastructure (CNKI) databases, supplemented by a manual search of references from retrieved articles. Pooled hazard ratios (HR) with 95% confidence intervals (95% CI) were calculated using the generic inverse variance and random-effect model to evaluate the association of PLR and LMR with prognostic variables in CRC, including overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS).

RESULTS

Thirty-three studies containing 15,404 patients met criteria for inclusion. Pooled analysis suggested that elevated PLR was associated with poorer OS (pooled HR = 1.57, 95% CI: 1.41 - 1.75, p< 0.00001, I2=26%) and DFS (pooled HR = 1.58, 95% CI: 1.31 - 1.92, p< 0.00001, I2=66%). Conversely, high LMR correlated with more favorable OS (pooled HR = 0.59, 95% CI: 0.50 - 0.68, p< 0.00001, I2=44%), CSS (pooled HR = 0.54, 95% CI: 0.40 - 0.72, p< 0.00001, I2=11%) and DFS (pooled HR = 0.82, 95% CI: 0.71- 0.94,p=0.005, I2=29%).

CONCLUSIONS

Elevated PLR was associated with poor prognosis, while high LMR correlated with more favorable outcomes in CRC patients. Pretreatment PLR and LMR could serve as prognostic predictors in CRC patients.

MiR-195 suppresses the metastasis and epithelial-mesenchymal transition of hepatocellular carcinoma by inhibiting YAP

MiR-195, a novel cancer-related microRNA, was previously reported to play an important role in many malignancies. This study aimed to investigate the role of miR-195 mediated epithelial-mesenchymal transition (EMT) and the progression of hepatocellular carcinoma (HCC) as well as the underlying mechanisms. Our result demonstrated that miR-195 were significantly down regulated in HCC and its decreased expression is associated with poor clinical features of HCC patients. Oppositely, expression level of YAP was significantly higher in HCC tissues, and the level of YAP in metastatic tissues was significantly higher. We also found that a strong inversely association between low level expression of miR-195 and high level of YAP in HCC tissues. Notably, this study confirmed that miR-195, YAP and their combination were valuable predictors for the prognosis of HCC patients. We also explored that miR-195 inhibits HCC growth and metastatic capacity. Mechanistically, we confirm that miR-195 inhibits the migration, invasion and EMT of HCC cells by suppressing YAP. Lastly, we revealed YAP was not only the downstream of miR-195 in HCC, but also mediated the promoting effects of miR-195 on the metastasis and EMT of HCC cells. Taken together, miR-195 inhibits the metastasis and EMT in HCC by targeting YAP. MiR-195/YAP pathway may potentially act as novel biomarker and attractive therapeutic target in HCC.

Hepatocellular carcinoma in elderly: Clinical characteristics, treatments and outcomes compared with younger adults

The number of elderly patients diagnosed with hepatocellular carcinoma (HCC) is expected to increase. The present study aims to evaluate the role of age on treatments and outcome of HCC patients. 1530 patients firstly diagnosed with HCC were retrospectively included and classified as older (≥65 years, n = 318, 21%) and younger patients (<65 years, n = 1212, 79%). The two groups were compared with clinical characteristics, tumor burden, Barcelona Clinics Liver Cancer (BCLC) stage, treatments and long-term prognosis. Elderly patients were more HCV infected, had more diabetes, poorer performance status, and were less aggressively treated. The proportion of HCC within BCLC stage 0-A, B or C was similar between the two groups, but elderly patients were more presented with BCLC stage D. The overall survival of older patients was poorer compared to younger patients before and after propensity score matching. However, elderly patients were less often effectively treated with surgery and loco-regional therapies across different BCLC stages. After stratified by BCLC stages or treatments, older patients showed comparable long-term outcome to younger patients. Performance status, BCLC stages and effective treatments, rather than age, was independent factors determining prognosis in the whole cohort and only elderly patients by multivariate analysis. In conclusion, older could have comparable survival to younger patients within the same tumor stage or after similar treatments. Thus, equally active treatments should be encouraged to elderly patients.

Lower Education and Household Income Contribute to Advanced Disease, Less Treatment Received and Poorer Prognosis in Patients with Hepatocellular Carcinoma

Understanding the ways in which socioeconomic status affects prognosis of hepatocellular carcinoma (HCC) is important for building up strategies eliminating the inequalities in cancer diagnosis and treatments among different groups, which, remains undetermined. In the present study, 1485 newly diagnosed HCC patients with complete demographic and clinical data were included. Socioeconomic data, including education, annual household income and residency was also reported by patients or families. In the present study, less educated patients were older, more female involved, poorly paid, more living in rural places, had more advanced tumor burden, received less curative and loco-regional therapies, and thus showed poorer short-term and long-term outcomes (in total or after surgical resection) than the highly educated. Patients with lower income were less educated, less treated, and more likely to live in rural places, had more advanced stages of HCC and thus poorer long-term survival (in total or after surgical resection) than higher income groups. In Cox regression analysis, lower household income was independently associated with poorer outcome (HR=1.2, 95% CI: 1.0-1.4, p=0.036). These results indicate that education and income are critically associated with early diagnosis, treatments and prognosis of HCC. Much more efforts should be taken to support the patients with less education and lower income to improve the outcomes of HCC.

microRNA-219-5p inhibits epithelial-mesenchymal transition and metastasis of colorectal cancer by targeting lymphoid enhancer-binding factor 1

Aberrant expression of microRNAs (miRs) has been shown to play a critical role in the pathogenesis and progression of tumors. microRNA‐219‐5p (miR‐219‐5p) has been reported to be abnormally expressed in some types of human tumors. However, the mechanism between miR‐219‐5p and colorectal cancer (CRC) metastasis remains unclear. In the present study, miR‐219‐5p was found to be downregulated in CRC tissue compared with matched normal tissue. Through luciferase reporter assay, we demonstrated lymphoid enhancer‐binding factor 1 (LEF1) as a direct target of miR‐219‐5p. Overexpression of miR‐219‐5p could inhibit motility, migration and invasion of CRC cells, and inhibit epithelial‐mesenchymal transition (EMT). Furthermore, silencing LEF1 phenocopied this metastasis‐suppressive function. The recovery experiment showed that re‐expression of LEF1 rescued this suppressive effect on tumor metastasis and reversed the expression of EMT markers caused by miR‐219‐5p. Additionally, we demonstrated that miR‐219‐5p exerted this tumor‐suppressive function by blocking activation of the AKT and ERK pathways. Finally, a nude mice experiment showed that miR‐219‐5p reduced the lung metastasis ability of CRC cells. Taken together, our findings indicate that miR‐219‐5p inhibits metastasis and EMT of CRC by targeting LEF1 and suppressing the AKT and ERK pathways, which may provide a new antitumor strategy to delay CRC metastasis.

Angiogenesis inhibitors for the treatment of small cell lung cancer (SCLC): A meta-analysis of 7 randomized controlled trials

BACKGROUND

This study aimed to assess the effectiveness and safety of angiogenesis inhibitors for the treatment of patients with small cell lung cancer (SCLC) via meta-analysis.

METHODS

Electronic databases including PubMed, Embase, and Cochrane Library were searched to look for eligible studies through February 1, 2016. RCTs comprising angiogenesis inhibitors and nonangiogenesis inhibitors for SCLC patients were investigated. The extracted data including overall survival (OS), progression-free survival (PFS), and objective response rate (ORR) were summarized. In addition, the common adverse events (AEs) were also explored.

RESULTS

There were 7 phase II/III RCTs, encompassing 1322 SCLC patients eligible for meta-analysis. In comparison to nonangiogenesis inhibitors, angiogenesis inhibitors treatment was not associated with improvement of PFS [HR = 0.87, 95% CI (0.74-1.02), P = 0.09), OS [HR = 0.99, 95% CI (0.88-1.12), P = 0.91], or ORR [OR = 1.12, 95% CI (0.85-1.47), P = 0.41). Also, there was no improvement in 1-year survival rate [OR = 0.96, 95% CI (0.74-1.19), P = 0.63)], 2-year survival rate [OR = 1.00, 95% CI (0.66-1.51), P = 1.00)] or 1-year progression-free survival rates [OR = 0.95, 95% CI (0.69-1.31), P = 0.76)]. However, from subgroup analyses, it was observed that angiogenesis inhibitors improved ORR [HR = 1.66 (95% CI 1.02-2.71), P = 0.04] in phase II studies and bevacizumab improved PFS [HR = 0.73 (95% CI 0.42-0.97), P = 0.04]. It is important to note that angiogenesis inhibitors reduced emesis [OR = 0.38, 95% CI (0.17-0.85), P = 0.02], but increased incidence of constipation [OR = 4.02, 95% CI (2.14-7.55), P < 0.0001) and embolism [OR = 2.24, 95% CI (1.45-3.47), P = 0.0003).

CONCLUSION

Adding angiogenesis inhibitors to chemotherapy did not improve PFS, OS, ORR, 1-year survival rate, 2-year survival rate or 1-year progression-free survival rate for SCLC. However, subgroup analysis revealed that bevacizumab enhanced PFS. Angiogenesis inhibitors also had a high incidence of constipation and embolism.

Polycomb complex protein BMI-1 promotes invasion and metastasis of pancreatic cancer stem cells by activating PI3K/AKT signaling, an ex vivo, in vitro, and in vivo study

Cancer stem cell theory indicates cancer stem cells are the key to promote tumor invasion and metastasis. Studies showed that BMI-1 could promote self-renew, differentiation and tumor formation of CSCs and invasion/metastasis of human cancer. However, whether BMI-1 could regulate invasion and metastasis ability of CSCs is still unclear. In our study, we found that up-regulated expression of BMI-1 was associated with tumor invasion, metastasis and poor survival of pancreatic cancer patients. CD133+ cells were obtained by using magnetic cell sorting and identified of CSCs properties such as self-renew, multi-differentiation and tumor formation ability. Then, we found that BMI-1 expression was up-regulated in pancreatic cancer stem cells. Knockdown of BMI-1 expression attenuated invasion ability of pancreatic cancer stem cells in Transwell system and liver metastasis capacity in nude mice which were injected CSCs through the caudal vein. We are the first to reveal that BMI-1 could promote invasion and metastasis ability of pancreatic cancer stem cells. Finally, we identified that BMI-1 expression activating PI3K/AKT singing pathway by negative regulating PTEN was the main mechanism of promoting invasion and metastasis ability of pancreatic CSCs. In summary, our findings indicate that BMI-1 could be used as the therapeutic target to inhibiting CSCs-mediated pancreatic cancer metastasis.

Notch Signaling Components: Diverging Prognostic Indicators in Lung Adenocarcinoma

Non-small-cell lung cancer (NSCLC) is a lethal and aggressive malignancy. Currently, the identities of prognostic and predictive makers of NSCLC have not been fully established. Dysregulated Notch signaling has been implicated in many human malignancies, including NSCLC. However, the prognostic value of measuring Notch signaling and the utility of developing Notch-targeted therapies in NSCLC remain inconclusive. The present study investigated the association of individual Notch receptor and ligand levels with lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC) prognosis using the Kaplan-Meier plotte database. This online database encompasses 2437 lung cancer samples. Hazard ratios with 95% confidence intervals were calculated. The results showed that higher Notch1, Notch2, JAG1, and DLL1 mRNA expression predicted better overall survival (OS) in lung ADC, but showed no significance in SCC patients. Elevated Notch3, JAG2, and DLL3 mRNA expression was associated with poor OS of ADC patients, but not in SCC patients. There was no association between Notch4 and OS in either lung ADC or SCC patients. In conclusion, the set of Notch1, Notch2, JAG1, DLL1 and that of Notch3, JAG2, DLL3 played opposing prognostic roles in lung ADC patients. Neither set of Notch receptors and ligands was indicative of lung SCC prognosis. Notch signaling could serve as promising marker to predict outcomes in lung ADC patients. The distinct features of lung cancer subtypes and Notch components should be considered when developing future Notch-targeted therapies.

Association between IL-27 2905T/G genotypes and the risk and survival of cervical cancer: a case-control study

BACKGROUND

Interleukin-27 (IL-27) has been recognized as a pleiotropic cytokine with both pro- and anti-inflammatory properties.

PATIENTS AND METHODS

A case-control study was conducted to investigate the possible associations of IL-27 gene polymorphisms with susceptibility to cervical cancer and clinical outcome.

RESULTS

Our results suggested that the IL-27 2905T/G was significantly associated with a decreased risk of cervical cancer. Further analysis showed IL-27 2905T/G genotypes were associated with advanced tumor stages of cervical cancer patients. More interestingly, the IL-27 2905T/G genotypes were statistically significantly associated with the survival in cervical cancer patients.

CONCLUSION

Our results showed that the IL-27 2905T/G genotypes were associated with decreased the susceptibility and development of cervical cancer in Chinese Han population.

Autophagy facilitates lung adenocarcinoma resistance to cisplatin treatment by activation of AMPK/mTOR signaling pathway

Resistance to cisplatin-based therapy is a major challenge in the control of lung cancer progression. However, the underlying mechanisms remain largely unclear. Autophagy is closely associated with resistance to lung cancer therapy, but the function of autophagy in cisplatin treatment is still controversial. Here, we investigated whether autophagy was involved in lung adenocarcinoma resistance to cisplatin and further elucidated the underlying molecular mechanisms. Cisplatin-refractory lung adenocarcinoma cells increased autophagic vacuole formation detected by monodansylcadaverine staining. When exposed to cisplatin, lung adeno-carcinoma cells demonstrated increased levels of autophagy detected by MAP1A/1B LC3B and mammalian homologue of yeast Atg6 (Beclin-1) expression using Western blot analysis. Activation of cisplatin-induced autophagic flux was increased by using chloroquine (CQ), which can accumulate LC3B-II protein and increase punctate distribution of LC3B localization. The combination of cisplatin with CQ was more potent than cisplatin alone in inhibiting lung adenocarcinoma cell growth, which also increased cisplatin-induced apoptosis. Compared to cisplatin treatment alone, the combination of cisplatin and CQ decreased p-AMPK and increased p-mTOR protein expressions, in addition, the AMPK inhibitor Compound C plus cisplatin downregulated p-AMPK and upregulated p-mTOR as well as depressed LC3B cleavage. These findings demonstrate that activation of autophagy is a hallmark of cisplatin exposure in human lung adenocarcinoma cells, and that there is a cisplatin-induced autophagic response via activation of the AMPK/mTOR signaling pathway. We speculate that autophagy can be used as a novel therapeutic target to overcome cisplatin-resistant lung adenocarcinoma.

Prognostic value of Notch-1 expression in hepatocellular carcinoma: a meta-analysis

Association of Notch-1 expression with prognosis of patients with hepatocellular carcinoma (HCC) remains controversial. We conducted a meta-analysis to reevaluate the association of Notch-1 expression with clinicopathological characteristics and prognosis of HCC. PubMed, Embase, Web of Science, and China National Knowledge Infrastructure were searched to look for relevant studies. The association between Notch-1 expression and clinicopathological parameters and overall survival (OS) was then reassessed using the meta-analysis for odds ratio (OR) or hazard ratio (HR) and 95% confidence interval (CI). A total of seven studies, including 810 HCC patients, were eligible for the meta-analysis. Our data showed that high Notch-1 expression was able to predict poor OS (HR 1.50, 95% CI 1.17–1.83, P=0.0001). The pooled OR showed that high Notch-1 expression was significantly associated with tumor metastasis (OR 0.37, 95% CI 0.16–0.86, P=0.02) and tumor size >5 cm (OR 0.48, 95% CI 0.26–0.88, P=0.02). In contrast, there was no association between high Notch-1 expression and tumor differentiation, late TNM stage, tumor number, and portal vein invasion of HCC. In conclusion, Notch-1 overexpression might predict poorer survival and more aggressive behavior in patients with HCC.

BMI-1, a promising therapeutic target for human cancer

BMI-1 oncogene is a member of the polycomb-group gene family and a transcriptional repressor. Overexpression of BMI-1 has been identified in various human cancer tissues and is known to be involved in cancer cell proliferation, cell invasion, distant metastasis, chemosensitivity and patient survival. Accumulating evidence has revealed that BMI-1 is also involved in the regulation of self-renewal, differentiation and tumor initiation of cancer stem cells (CSCs). However, the molecular mechanisms underlying these biological processes remain unclear. The present review summarized the function of BMI-1 in different human cancer types and CSCs, and discussed the signaling pathways in which BMI-1 is potentially involved. In conclusion, BMI-1 may represent a promising target for the prevention and therapy of various cancer types.

In vitro synergistic antitumor efficacy of sequentially combined chemotherapy/icotinib in non‑small cell lung cancer cell lines

The concurrent administration of chemotherapy and epidermal growth factor receptor‑tyrosine kinase inhibitors (EGFR‑TKIs) has previously produced a negative interaction and failed to confer a survival benefit to non‑small cell lung cancer (NSCLC) patients compared with first‑line cytotoxic chemotherapy. The present study aimed to investigate the optimal schedule of the combined treatment of cisplatin/paclitaxel and icotinib in NSCLC cell lines and clarify the underlying mechanisms. HCC827, H1975, H1299 and A549 human NSCLC cell lines with wild‑type and mutant EGFR genes were used as in vitro models to define the differential effects of various schedules of cisplatin/paclitaxel with icotinib treatments on cell growth, proliferation, cell cycle distribution, apoptosis, and EGFR signaling pathway. Sequence‑dependent antiproliferative effects differed among the four NSCLC cell lines, and were not associated with EGFR mutation, constitutive expression levels of EGFR or downstream signaling molecules. The antiproliferative effect of cisplatin plus paclitaxel followed by icotinib was superior to that of cisplatin or paclitaxel followed by icotinib in the HCC827, H1975, H1299 and A549 cell lines, and induced more cell apoptosis and G0/G1 phase arrest. Cisplatin and paclitaxel significantly increased the expression of EGFR phosphorylation in the HCC827 cell line. However, only paclitaxel increased the expression of EGFR phosphorylation in the H1975 cell line. Cisplatin/paclitaxel followed by icotinib influenced the expression of p‑EGFR and p‑AKT, although the expression of p‑ERK1/2 remained unchanged. The results suggest that the optimal schedule of the combined treatment of cisplatin/paclitaxel and icotinib differed among the NSCLC cell lines. The results also provide molecular evidence to support clinical treatment strategies for NSCLC patients.

SDF-1/CXCR4 promotes epithelial-mesenchymal transition and progression of colorectal cancer by activation of the Wnt/β-catenin signaling pathway

Stromal cell-derived factor 1 (SDF-1) and its receptor, CXCR4, play an important role in angiogenesis and are associated with tumor progression. This study aimed to investigate the role of SDF-1/CXCR4-mediated epithelial-mesenchymal transition (EMT) and the progression of colorectal cancer (CRC) as well as the underlying mechanisms. The data showed that expression of CXCR4 and β-catenin mRNA and protein was significantly higher in CRC tissues than in distant normal tissues. CXCR4 expression was associated with β-catenin expression in CRC tissues, whereas high CXCR4 expression was strongly associated with low E-cadherin, high N-cadherin, and high vimentin expression, suggesting a cross talk between the SDF-1/CXCR4 axis and Wnt/β-catenin signaling pathway in CRC. In vitro, SDF-1 induced CXCR4-positive colorectal cancer cell invasion and EMT by activation of the Wnt/β-catenin signaling pathway. In contrast, SDF-1/CXCR4 axis activation-induced colorectal cancer invasion and EMT was effectively inhibited by the Wnt signaling pathway inhibitor Dickkopf-1. In conclusion, CXCR4-promoted CRC progression and EMT were regulated by the Wnt/β-catenin signaling pathway. Thus, targeting of the SDF-1/CXCR4 axis could have clinical applications in suppressing CRC progression.

Implications of biomarkers in human hepatocellular carcinoma pathogenesis and therapy

Hepatocellular carcinoma (HCC) is one of the most frequent tumors worldwide and accounts for approximately one-third of all malignancies. In the past decade, advances have been made to improve the prognosis of HCC, including improvement in the clinical diagnosis of early-stage HCC using molecular biomarkers and molecular-targeted therapy to treat advanced HCC. However, the diagnosis, pathogenesis and targeted therapy of HCC are not completely independent, and should be comprehensively studied. For example, a number of tumor markers provide useful clinical information not only for prognosis, but also in pathogenesis and treatment efficacy. Therefore, this review will focus on the role of several specific biomarkers implicated in the pathogenesis of HCC and several promising molecular-targeted drugs that target the biomarkers of HCC.

Suppression of lung cancer cell invasion by LKB1 is due to the downregulation of tissue factor and vascular endothelial growth factor, partly dependent on SP1

LKB1 encodes a serine/threonine kinase generally inactivated in many human cancers, which mediates cancer cell proliferation, migration and differentiation. Recent studies indicated that LKB1 exhibits potent anti-metastatic activity. However, the underlying molecular mechanisms of this activity remain unclear. In this study, we re‑introduced LKB1 into A549 lung cancer cells that lack the LKB1 gene to investigate how LKB1 affects tumor invasiveness and metastasis. We demonstrated that overexpression of the LKB1 protein in lung cancer cells resulted in significant inhibition of invasion. Furthermore, transfected lung cancer cells with LKB1 suppressed tissue factor (TF) and vascular endothelial growth factor (VEGF) expression at both the mRNA and protein levels. Here, we provided evidence showing that downregulation of TF and VEGF by LKB1 is correlated well with the inhibition of cell invasion. Overexpression of the LKB1 protein in human lung cancer is significantly associated with a decrease in activity and expression of the transcription factor SP1. Constitutive activation of the transcription factor Sp1 plays a critical role in TF and VEGF overexpression. We conclude that suppression of lung cancer cell invasion by LKB1 through downregulation of TF and VEGF may partly depend on its inhibitory effect on the transcription factor Sp1. Collectively, our data provide a novel molecular mechanism for the antitumor activity of LKB1 and may help further improve its effectiveness in controlling lung cancer growth and invasion.

Gemcitabine inhibits the micrometastasis of non-small cell lung cancer by targeting the EpCAM-positive circulating tumor cells via the HGF/cMET pathway

Recurrence and metastasis are responsible for the death of non-small cell lung cancer (NSCLC) patients. Circulating tumor cells (CTCs) in the metastatic pathway have proven to be essential. This pilot study evaluated the sensitivity of gemcitabine in micrometastasis and CTCs from NSCLC patients. EpCAM-positive CTCs were detected in forty patients with NSCLC at treatment initiation and disease evaluation time-points. EpCAM-positive CTCs were defined as EpCAM-positive and CD45-negative. Total RNA was isolated from EpCAM-enriched CTCs and cytokeratin levels were detected by PCR. The HGF/cMET pathway was evaluated in CTCs from patients with different treatments and in A549 cells. The EMT-related markers were analyzed by IHC. We further explored the predictive value of baseline CTCs in patients that were receiving different treatments. The median number of CTCs in NSCLC patients was 65 CTCs/ml more than in the healthy 23?fold (median, 5.2 CTCs/ml). The mean change in cell count was significantly different for patients with gemcitabine compared to patients with non-gemcitabine treatments (-86.28 vs. -15.23/ml; P<0.05). A significant decrease was noted in the expression of cytokeratin in the CTCs of the two groups (P<0.05). The HGF/cMET pathway was inactivated in CTCs and A549 cells treated with gemcitabine, and the cell migration and invasion abilities were inhibited by gemcitabine via the HGF/cMET pathway. Furthermore, the decreased cell migration and invasion abilities may also be involved in the inhibition of the epithelial-mesenchymal transition (EMT) by gemcitabine. At a median follow-up of 36 months, the CTC count was confirmed to be a robust prognostic marker in the NSCLC population (CTCs >151, median: 15.0 months and CTCs <151, median: 32.0 months). Additionally, the survival rate in the gemcitabine group (24 months) was better than in non-gemcitabine group (21 months), suggesting a therapeutic benefit for NSCLC patient survival with the common therapy plus gemcitabine. Gemcitabine treatment decreased EpCAM-positive CTCs in NSCLC patients and inhibited EMT by the HGF/cMET pathway.

Expression and significance of the novel tumor-suppressor gene SMG-1 in hepatocellular carcinoma

Recent studies have demonstrated that SMG-1, a newly characterized member of the family of phosphatidylinositol 3-kinase-related protein kinases (PIKKs), is involved in tumorigenesis as a new tumor suppressor. However, its expression and significance in hepatocellular carcinoma (HCC) remain obscure. The present study investigated SMG-1 expression in HCC tissue specimens, aimed at defining the association with clinicopathological significance. Both immunohistochemistry and qRT-PCR were employed to analyze SMG-1 expression in 157 HCC and corresponding distant normal tissue specimens. The results revealed that expression of SMG-1 was significantly lower in the HCC tissue specimens than that in the distant normal tissues. Moreover, a lower expression level of SMG-1 was significantly correlated with serum α-fetoprotein level (P=0.001), poorly differentiated tumors (P=0.009) and more advanced TNM stage (P<0.001). Further study showed that SMG-1 expression was exactly associated with tumor differentiation and clinical stage in HCC. Kaplan-Meier analysis indicated that low SMG-1 expression was related to poor overall survival, and the prognostic impact of SMG-1 was further confirmed by stratified survival analysis. Importantly, multivariate analysis revealed that low SMG-1 expression was an independent prognostic marker for an unfavorable overall survival. We conclude that SMG-1 is downregulated in HCC and may represent a promising biomarker for predicting the prognosis of HCC, including the prognosis of early-stage patients.

Cyclooxygenase-2 inhibitor is a robust enhancer of anticancer agents against hepatocellular carcinoma multicellular spheroids

Purpose

Celecoxib, an inhibitor of cyclooxygenase-2 (COX2), was investigated for enhancement of chemotherapeutic efficacy in cancer clinical trials. This study aimed to determine whether celecoxib combined with 5-fluorouracil or sorafenib or gefitinib is beneficial in HepG2 multicellular spheroids (MCSs), as well as elucidate the underlying mechanisms.

Methods

The human hepatocellular carcinoma cell line HepG2 MCSs were used as in vitro models to investigate the effects of celecoxib combined with 5-fluorouracil or sorafenib or gefitinib treatment on cell growth, apoptosis, and signaling pathway.

Results

MCSs showed resistance to drugs compared with monolayer cells. Celecoxib combined with 5-fluorouracil or sorafenib exhibited a synergistic action. Exposure to celecoxib (21.8 μmol/L) plus 5-fluorouracil (8.1 × 10⁻³ g/L) or sorafenib (4.4 μmol/L) increased apoptosis but exerted no effect on COX2, phosphorylated epidermal growth-factor receptor (p-EGFR) and phosphorylated (p)-AKT expression. Gefitinib (5 μmol/L), which exhibits no growth-inhibition activity as a single agent, increased the inhibitory effect of celecoxib. Gefitinib (5 μmol/L) plus celecoxib (21.8 μmol/L) increased apoptosis. COX2, p-EGFR, and p-AKT were inhibited.

Conclusion

Celecoxib combined with 5-fluorouracil or sorafenib or gefitinib may be superior to single-agent therapy in HepG2 MCSs. Our results provided molecular evidence to support celecoxib combination-treatment strategies for patients with human hepatocellular carcinoma. MCSs provided a good model to evaluate the interaction of anticancer drugs.

Knockdown of lymphoid enhancer factor 1 inhibits colon cancer progression in vitro and in vivo

Expression of lymphoid enhancer factor 1 (LEF1) is frequently altered in different human cancers. This study aimed to assess LEF1 expression in colon cancer tissues and to explore changed phenotypes, gene expressions, and the possible mechanism after knocked down LEF1 expression in colon cancer cell lines. A total of 106 colon cancer and matched paratumorous normal tissues were used to assess LEF1 expression using immunohistochemistry and qRT-PCR. LEF1 lentivirus was used to knockdown LEF1 expression for the assessment of cell viability, cell cycle distribution, apoptosis, and gene expressions. The nude mouse xenograft assay was performed to detect the effects of LEF1 knockdown in vivo. The data showed that the levels of LEF1 mRNA and protein were significantly increased in human colon cancer tissues compared to the matched paratumorous normal tissues and were associated with infiltration depth, lymph node and distant metastases, advanced TNM (tumor-node-metastasis) stages, and shorter overall survival. Furthermore, LEF1 knockdown reduced tumor cell viability, invasion capacity, MMP2 and MMP-9 expression, but induced apoptosis. Nude mouse xenograft assay showed that LEF1 knockdown suppressed tumor formation and growth in vivo. In addition, the expression of Notch pathway-related proteins RBP-jκ and Hes1 was reduced in LEF1 knockdown cells. Taken together, LEF1 protein was overexpressed in colon cancer tissues and knockdown of LEF1 expression inhibited colon cancer growth in vitro and in vivo. These data suggest that targeting of LEF1 expression should be further evaluated for colon cancer prevention and therapy.

CDK-associated Cullin 1 can promote cell proliferation and inhibit cisplatin-induced apoptosis in the AGS gastric cancer cell line

Background

Gastric cancer is a common and highly lethal malignancy in the world, but its pathogenesis remains elusive. In this study, we focus on the biological functions of CDK-associated Cullin1 (CAC1), a novel gene of the cullin family, in gastric cancer, which may help us to further understand the origin of this malignancy.

Methods

The AGS and MGC803 gastric cancer cell lines and the GES-1 gastric mucosa cell line were selected for study. At first, CAC1 expressions of those cell lines were examined by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and western blot examinations, then CAC1 small interfering RNA (CAC1-siRNA) were designed and transfected into the AGS cell line with a relatively high level of CAC1. Once CAC1 was silenced, a series of biological characteristics of AGS cells such as cell proliferation, cell cycle, apoptosis, and expressions of apoptosis-related genes (P53, BCL2 and BAX) were determined by MTT, flow cytometry, qRT-PCR and western blot, respectively.

Results

CAC1 expression of AGS or MGC803 was much higher than that of GES-1. After CAC1 expression was effectively depressed by RNA interference in AGS cells, significant cell growth inhibition occurred. Furthermore, the proportion of cells treated with CAC1-siRNA increased in the G1 phase and decreased in the S phase, indicative of G1 cell cycle arrest. More importantly, the proportions of early/late apoptosis in AGS cells were enhanced with cis-diaminedichloroplatinum (cisplatin, CDDP) treatment, but to a higher extent with cisplatin plus CAC1-siRNA. Interestingly, BCL2 mRNA copies showed about a 30% decrease in the cisplatin group, but dropped by around 60% in the cisplatin plus CAC1-siRNA group. Conversely, the P53 mRNA expressions obtained nearly a two-fold increase in the cisplatin group, in addition to a five-fold increase in the cisplatin plus CAC1-siRNA group, and the BAX mRNA levels had almost a two- and four-fold augmentation, respectively. Meanwhile, P53, BAX and BCL2 showed the same alteration patterns in western blot examinations.

Conclusions

CAC1 can promote cell proliferation in the AGS gastric cancer cell line. Moreover, it can prevent AGS cells from experiencing cisplatin-induced apoptosis via modulating expressions of P53, BCL2 and BAX.

PTEN enhances the sensitivity of human hepatocellular carcinoma cells to sorafenib

Hepatocellular carcinoma (HCC) is a complex and heterogeneous tumor with several genomic alterations and ranks as the third highest cause of cancer-related death globally. The unresectable or metastatic HCC has very poor prognosis. Although multikinase inhibitor sorafenib can increase the survival of patients with advanced HCC, it is becoming apparent that combination therapies are critical to overcome the complex genomic aberrations in HCC. PTEN, as one of the most commonly inactivated genes in HCC, exerts a wide range of antitumor effects. In this study, we found that PTEN was downregulated in HCC tissues, especially in those tissues with extrahepatic metastasis. And negative PTEN expression cases showed increased proliferation activity. Overexpression of PTEN significantly reduced the proliferation of tumor cells HepG2. In addition, HepG2 cells transfected with PTEN were more sensitive to sorafenib in terms of its ability to inhibit proliferation and to induce apoptosis. Moreover, overexpression of PTEN decreased phosphorylation of MEK, a key downstream effector of RAF/MEK/ERK cascade, and levels of cyclin D1, antiapoptotic Bcl-2, and VEGF. These observations indicated that combination therapies with sorafenib and PTEN overexpression have potential to further improve therapeutic options for HCC.

Cancer stem cells niche: a target for novel cancer therapeutics

Nowadays, cancer has been a frequent disease, and the first or second most common cause of death worldwide. Despite a better understanding of the biology of cancer cells, the therapy of most cancers has not significantly changed for the past four decades. It is because conventional chemotherapies and/or radiation therapies are usually designed to eradicate highly proliferative cells. Mounting evidence has implicated that cancer is a disease of stem cells. Cancer stem cells (CSC) are often relatively quiescent, and therefore may not be affected by therapies targeting rapidly dividing cells. Like normal stem cells (NSC) residing in a "stem cell niche" that maintains them in a stem-like state, CSC also require a special microenvironment to control their self-renewal and undifferentiated state. The "CSC niche" is likely to be the most crucial target in the treatment of cancer. In this article, we summarize the current knowledge regarding CSC and their niche microenvironments. Understanding of CSC's origin, molecular profile, and interaction with their microenvironments, this could be a paradigm shift in the treatment of cancer, away from targeting the blast cells and towards the targeting of the CSC, thus improving therapeutic outcome.

Bmi1 knockdown inhibits hepatocarcinogenesis

Although Bmi1 is well established as one of the most commonly activated oncogenes, the precise role of Bmi1 during hepatocarcinogenesis remains unclear. In addition, Bmi1 provides a potential therapeutic target for the future treatment of hepatocellular carcinoma (HCC). In this study, the expression of Bmi1 in HCC tissues was evaluated by immunohistochemistry and western blot analysis. We found that Bmi1 was much more highly expressed in HCC tissue compared to normal liver tissue. The shRNA-mediated knockdown of Bmi1 was used to assess the effects of Bmi1 in hepatocarcinogenesis. Bmi1 downregulation reduced cell growth and tumorsphere formation in vitro. A cell cycle analysis using flow cytometry clarified that Bmi1 knockdown blocked the cell cycle transition from the G0/G1 to the S phase. Additionally, the Bmi1 knockdown led to reduced tumorigenicity in vivo. Furthermore, Bmi1 expression enhanced the sensitivity of HCC to the therapeutic agent, sorafenib. Taken together, the current results demonstrate that Bmi1 functions as a promoter in cell proliferation and hepatocarcinogenesis, providing a potential therapeutic target for the future treatment of HCC.

The deoxycholic acid targets miRNA-dependent CAC1 gene expression in multidrug resistance of human colorectal cancer

There is evidence indicating that bile acid is a promoter of colorectal cancer. Deoxycholic acid modifies apoptosis and proliferation by affecting intracellular signaling and gene expression. We are interested in revealing the relationship between deregulated miRNAs and deoxycholic acid in colorectal cancer development. We found that miR-199a-5p was expressed at a low level in human primary colonic epithelial cells treated with deoxycholic acid compared with control, and miR-199a-5p was significantly down-regulated in colorectal cancer tissues. The miR-199a-5p expression in colorectal cancer cells led to the suppression of tumor cell growth, migration and invasion. We further identified CAC1, a cell cycle-related protein expressed in colorectal cancer, as a miR-199a-5p target. We demonstrated that CAC1 is over-expressed in malignant tumors, and cellular CAC1 depletion resulted in cancer growth suppression. HCT-8 cells transfected with a miR-199a-5p mimic or inhibitor had a decrease or increase in CAC1 protein levels, respectively. The results of the luciferase reporter gene analysis demonstrated that CAC1 was a direct miR-199a-5p target. The high miR-199a-5p expression and low CAC1 protein expression reverse the tumor cell drug resistance. We conclude that miR-199a-5p can regulate CAC1 and function as a tumor suppressor in colorectal cancer. Therefore, the potential roles of deoxycholic acid in carcinogenesis are to decrease miR-199a-5p expression and/or increase the expression of CAC1, which contributes to tumorigenesis in patients with CRC. These findings suggest that miR-199a-5p is a useful therapeutic target for colorectal cancer.

Activation of PI3 kinase/Akt/HIF-1α pathway contributes to hypoxia-induced epithelial-mesenchymal transition and chemoresistance in hepatocellular carcinoma

Hypoxia is known to promote malignant progression and to induce chemoresistance in cancer. However, the exact mechanisms driving hypoxia induced malignance remain elusive. We found that with exposure to hypoxic condition, hepatocellular carcinoma (HCC) cells experienced epithelial-mesenchymal transition (EMT), with increased cell migration and invasion, and exhibited high resistance to chemotherapy. We demonstrated that hypoxia-induced EMT and chemoresistance were accompanied by increased HIF-1α expression and activation of Akt. HIF-1α could be blocked by PI3K inhibitor LY294002, indicating HIF-1α activation was regulated by PI3K/Akt pathway. Furthermore, we showed that inhibition of PI3K/Akt and HIF-1α enhanced the therapeutic efficacy of hypoxic chemotherapy in the HCC xenograft model. Our findings indicate that the activation of PI3K/Akt/HIF-1α pathway plays a critical role in mediating hypoxia-induced EMT and drug resistance leading to unfavorable treatment outcome. Our study provides novel insights into the malignant progression triggered by hypoxic microenvironment in HCC cells.

PTEN inhibits the migration and invasion of HepG2 cells by coordinately decreasing MMP expression via the PI3K/Akt pathway

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Most patients with HCC die within one year after diagnosis largely because of frequent tumor recurrence and metastasis. The tumor suppressor gene PTEN (phosphatase and tensin homolog deleted on chromosome 10) is one of the most commonly lost or mutated genes in a variety of human cancers, including HCC. PTEN antagonizes phosphoinositide-3-kinase (PI3K)/ATP-dependent tyrosine kinase (Akt) signaling, thereby negatively regulating a multitude of biological aggressive tumor behaviors. However, the direct role and mechanism of PTEN in the regulation of invasion and invasion-related gene expression in HCC remain to be elucidated. In this study, we introduced wild-type PTEN or phosphatase-dead PTEN into HepG2 cells that have low expression of PTEN. We found that overexpression of PTEN inhibits HepG2 cell growth via cell cycle arrest without inducing apoptosis. Matrigel invasion and scratch assays indicated that PTEN significantly inhibits HepG2 cell migration and invasion in vitro. On the molecular level, overexpression of PTEN suppressed expression of matrix metalloproteinase (MMP)-2 and -9 in HepG2 cells. Similarly, treatment of HepG2 cells with the PI3K/Akt pharmacological inhibitor, LY294002, potently suppressed cell migration and invasion as well as expression of MMPs. However, the phosphatase-dead PTEN mutant did not exert the same effects. Our data show that PTEN not only inhibits HepG2 cell growth via cell cycle arrest, but also suppresses cell invasion in a PI3K/Akt/MMP-dependent manner, which suggests that loss or mutation of PTEN may contribute to increased cell invasion and facilitates HCC progression.

Endothelial cells promote the proliferation of lymphocytes partly through the Wnt pathway via LEF-1

The function of T cells and B cells is to recognize specific "non-self" antigens, during a process known as antigen presentation. Once they have identified an invader, the cells generate specific responses that are tailored to maximally eliminate specific pathogens or pathogen-infected cells. Endothelial cells (ECs) can trigger the activation of T cells through their class I and class II MHC molecules. In this study, we examined the effect of ECs on the proliferation of lymphocytes. We report that the proliferation of T and B cells can be improved by interaction with ECs. LEF-1 is one of the main molecular mediators in this process, and the inhibition of LEF-1 induces apoptosis. These results suggest that LEF-1 modulates positively the proliferation of lymphocytes induced by their interaction with ECs.

Overexpression of the LKB1 gene inhibits lung carcinoma cell proliferation partly through degradation of c-myc protein

LKB1 encodes a serine/threonine kinase generally inactivated in human lung cancers, which mediates cancer cell proliferation, migration and differentiation, but its biological function has not been completely elucidated. In this study, we demonstrated that LKB1 was associated with a substantial reduction of c-myc expression by using an inducible LKB1 expression system in the LKB1-null lung cell line A549. Nevertheless, the reduction of the c-Myc gene expression was not accompanied by corresponding reduction of mRNAs but protein, which can be abrogated by a proteosome inhibitor (MG132), suggesting that the reduction was associated with their increased degradation rather than transcriptional controls. Our results implied that the expression of c-Myc protein decreased by LKB1 in transfected cells may be a contributory factor in the process of cell proliferation. Overexpression of the LKB1 gene could inhibit the activation of ERK1/2 and STAT3 signaling pathways involved in the cell proliferation. Thus, LKB1-induced functional operation on c-Myc in promoting cell proliferation may occur in a novel mechanism, which may be regulated by ERK1/2 and/or STAT3 signal pathways in human lung carcinoma cells. Furthermore, our results give some insights into the understanding of how LKB1 inactivation contributes to lung carcinogenesis and emphasizes the central role played by LKB1 in lung cancer development.

Survival advantages of multicellular spheroids vs. monolayers of HepG2 cells in vitro

Mammalian cells grow in three-dimensions (3-D) in vivo. Commonly used two-dimensional (2-D) cell cultures are inadequate to recreate the biological microenvironment of tumor cells. The potentially different outcomes from 2-D and 3-D culture systems may have a significant impact on the relevance of experimental findings. The purpose of this study was to characterize the human hepatoma cell line HepG2 in 2-D and 3-D cultures. HepG2 cells in 2-D and 3-D cultures were treated with cisplatin, 5-fluorouracil, and adriamycin and were analyzed by scanning electron microscopy and transmission electron microscopy. Cell cycle progression and apoptosis were detected by flow cytometry. Inhibition of cell proliferation was quantified by MTT assay. The expression of E-cadherin, CD44v6, VEGF, KDR, endostatin, Bax, and cytochrome-c were analyzed by immunohistochemical (IHC) staining. As compared to the 2-D monolayer culture, the 3-D multicellular spheroids (MCS) of HepG2 cells featured a greater fraction of cells in G1 phase and were organized with more abundant cell-cell adhesion. In addition, cells in MCS were significantly less apoptotic in maintenance culture media and were more resistant to drug-induced apoptosis. E-cadherin, CD44v6, VEGF, KDR, endostatin, and cytochrome-c levels were increased in MCS as compared to 2-D cell cultures. In conclusion, MCS conferred differentiated phenotypes including increased cell-cell adhesion and G1 phase cell cycle arrest, enhanced cellular resistance to apoptosis, and upregulated angiogenic potential. Based on our data, a multicellular morphological hierarchy may sustain the growth/survival advantages of cancer cells in vivo. Therefore, a 3-D culture system should be the preferred technique for cancer biology investigation.

[Effect of transfection of LKB1 on biological behavior of human lung adenocarcinoma cells]

AIM

To determine the effects of exogenous LKB1 gene on biological behavior of lung carcinoma cells.

METHODS

Nest PCR was used to clone LKB1 gene pcDNA-LKB1 and pcDNA3.1 were introduced into A549 cell line by lipofectin transfection, and the A549 cells stably expressing LKB1 gene were established by G418 selection. The expression of LKB1 and STAT3 protein was detected by Western blot. Cell proliferation was observed by growth curve and clone formation. Cell cycle and apoptosis were assayed by flow cytometry(FCM).

RESULTS

A549 cells stably expressing LKB1 protein were established. Compared with the vector transfected cells, the positive clone cells grew more slowly. FCM showed that more positive clone cells went into phase G0/G1 and fewer cells went into phase S. Moreover, there was significant difference on apoptosis between the two group cells.

CONCLUSION

LKB1 protein might inhibit malignant biological behavior of A549 cells partly by down-regulating the tyrosine-phosphorylated level of STAT3 protein.

WITHDRAWN: Treatment of combining antiangiogenic therapy and cytotoxic chemotherapy reduce the cancer stem-like cell fraction in hepatocarcinoma xenografts

This article has been withdrawn consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The Publisher apologizes for any inconvenience this may cause.

[Effect of extract of Ginkgo biloba on doxorubicin-associated cardiotoxicity in patients with breast cancer]

OBJECTIVE

To study the effect of extract of Ginkgo biloba (Egb761) on doxorubicin-associated cardiotoxicity in patients with breast cancer (BC).

METHODS

Sixty BC patients in stage IV were randomly assigned to two groups, the control group was treated with chemotherapy, using 4 cycles of PA protocol alone and the treated group with the same chemotherapy and Egb761. Changes in electrocardiogram (ECG), myocardial enzyme spectrum (MES) and ultrasono-cardiogram (USCG) before and after treatment were observed.

RESULTS

After treatment, the incidence of abnormal ECG was lower in the treated group than in the control group (6.7% vs 30.0%); significant differences were found between the two groups in the parameters of MES (P< 0.05); USCG showed significant difference between the two groups in left ventricular diastolic diameter (LVDd), left ventricular systolic diameter (LVDs), ratio of early and late diastolic transmitral peak flow velocity (E/A) and fractional shortening (FS), while there was no significant difference in ejection fraction (EF).

CONCLUSION

Egb761 is an ideal drug for preventing and reducing the acute doxorbincin-induced cardiotoxicity; it could also be helpful for alleviating the chronic cardiotoxicity.

Chinese medicinal compound delisheng has satisfactory anti-tumor activity, and is associated with up-regulation of endostatin in human hepatocellular carcinoma cell line HepG2 in three-dimensional culture

AIM: To investigate the multicellular resistance of human hepatocellular carcinoma HepG2 cells in three-dimensional culture to delisheng, 5-fluorouracil and adriamycin, and the possible molecular mechanisms of delisheng.

METHODS: Human hepatocellular carcinoma HepG2 cells were cultured with a liquid overlay technique. After the formation of multicellular spheroids, morphology was analyzed by phase contrast microscopy, scanning electron microscopy and transmission electron microscopy. Sensitivity of HepG2 cells to delisheng, 5-fluorouracil and adriamycin was investigated by MTT assay in multicelluar spheroids and monolayers. Vascular endothelial growth factor (VEGF) and endostatin expression were analyzed in multicellular spheroids treated with delisheng, 5-fluorouracil, adriamycin and negative control PBS, with immunohistochemical staining.

RESULTS: Multicellular spheroids exhibited structural characteristics somewhat different to those in monolayers. The cells in three-dimensional cell culture turned out to be less sensitive to delisheng, 5-fluorouracil and adriamycin than the cells cultured in monolayer. This showed that delisheng had a satisfactory cells inhibition ratio compared to 5-fluorouracil and adriamycin. Immunohistochemical staining showed that VEGF and endostatin expression was positive during growth as multicellular spheroids, and endostatin expression in spheroids with treatment of delisheng was higher than that with 5-fluorouracil, adriamycin and PBS (139.35 ± 7.83, 159.23 ± 10.34, 162.83 ± 3.47 and 148.48 ± 11.06, P < 0.05).

CONCLUSION: Chinese medicine compound delisheng has satisfactory anti-tumor activity in HepG2 cells in three-dimensional culture, and the effects are associated with up-regulation of endostatin.

Selenoprotein P mRNA expression in human hepatic tissues

AIM: To investigate the expression of selenoprotein P mRNA (SePmRNA) in tissues of normal liver, liver cirrhosis and hepatocellular carcinoma (HCC), and its relationship with HCC occurrence and development.

METHODS: The expression of SePmRNA in tissues of normal liver, liver cirrhosis and HCC were detected by in situ hybridization using a cDNA probe.

RESULTS: The enzyme digesting products of P^{Bluescript-Human Selenoprotein P} were evaluated by electrophoresis. The positive expression of SePmRNA was found in the tissues of normal liver, liver cirrhosis and HCC. The expression of SeP mRNA was found in hepatic interstitial substance, especially in endothelial cells and lymphocytes of vasculature. The positive rate of SePmRNA in normal liver tissue was 84.6% (11/13) and the positive signals appeared in the nucleus and cytoplasm, mostly in the nucleolus, and the staining granules were larger in the nucleolus and around the nucleus. The positive rate of SePmRNA in liver cirrhosis tissue was 45.0% (9/20) and the positive signals were mainly in the nucleolus and cytoplasm, being less around the nucleus and inner nucleus than that in normal liver tissue. The positive rate of SePmRNA in HCC tissue was 30.0% (9/30) and the positive signals were in the cytoplasm, but less in the nucleus.

CONCLUSION: SePmRNA expression in the tissues of normal liver and HCC is significantly different (84.6% vs 30.0%, P = 0.003), suggesting that SeP might play a role in the occurrence and development of HCC.

Inhibitory effect of Fuzheng Yiliuyin in combination with chemotherapeutics on human gastric carcinoma cell strain

AIM: To study the inhibitory effects of Fuzheng Yiliuyin (Decoction for Suppressing Tumors by Strengthening the Body Resistance) in combination with chemotherapeutics on human gastric carcinoma cell strain.

METHODS: Fuzheng Yiliuyin (ZY) combined with various kinds of chemotherapeutics was put into two kinds of cultivated human gastric carcinoma cell strains, then its inhibitory effects on human gastric carcinoma cell strains were determind by the MTT method. Flow cytometer was used to assay the apoptosis rate, and the ultrastructure of gastric carcinoma cells was observed under transmission electron microscope.

RESULTS: Obvious apoptosis was seen in gastric carcinoma cells after treatment with ZY for 72 h. ZY and chemical drugs had synergistic inhibition effects on the cultivated gastric carcinoma cells, but the effects were different on various cell strains. The inhibitory effects of ZY could be strengthened by cytotoxic action and apoptosis. ZY combined with fluorouracil, etoposide and cisplatin (EFP) chemotherapeutics had better inhibitory effects on SGC-7901, while ZY combined with EFP or with DDP chemotherapeutics had better inhibitory effects than other drugs on MGC-803.

CONCLUSION: ZY induces apoptosis and inhibits the growth of gastric carcinoma cells. ZY has the synergistic function of chemotherapeutics.

Targeting radioimmunotherapy of hepatocellular carcinoma with iodine (131I) metuximab injection: clinical phase I/II trials

PURPOSE

HAb18G/CD147 is a hepatocellular carcinoma (HCC)-associated antigen. We developed iodine (131I) metuximab injection (Licartin), a novel 131I-labeled HAb18G/CD147-specific monoclonal antibody Fab'2 fragment, and evaluated its safety, pharmacokinetics, and clinical efficacy on HCC in Phase I/II trials.

METHODS AND MATERIALS

In a Phase I trial, 28 patients were randomly assigned to receive the injection in 9.25-, 18.5-, 27.75-, or 37-MBq/kg doses by hepatic artery infusion. In a multicenter Phase II trial, 106 patients received the injection (27.75 MBq/kg) on Day 1 of a 28-day cycle. Response rate and survival rate were the endpoints.

RESULTS

No life-threatening toxic effects were found. The safe dosage was 27.75 MBq/kg. The blood clearance fitted a biphasic model, and its half-life was 90.56-63.93 h. In the Phase II trial, the injection was found to be targeted and concentrated to tumor tissues. Of the 73 patients completing two cycles, 6 (8.22%) had a partial response, 14 (19.18%) minor response, and 43 (58.90%) stable disease. The 21-month survival rate was 44.54%. The survival rate of progression-free patients was significantly higher than that of patients with progressive disease after either one or two cycles (p < 0.0001 or p = 0.0019).

CONCLUSION

Iodine (131I) metuximab injection is safe and active for HCC patients.