Liver X receptors agonist T0901317 exerts ferroptosis sensitization in cancer.

Numerous studies have confirmed the anticancer effects of ferroptosis on a wide range of tumors, specifically in providing new perspectives for tackling drug resistance and treating refractory tumors. Notably, mechanisms of improving tumor susceptibility to ferroptosis have been a focus of current research. This study discovered that co-treatment of LXRS agonist T0901317 and ferroptosis inducers (FINs) significantly inhibited the proliferation of cancer cells, this inhibition effect could be reversed by specific inhibitors of ferroptosis and accompanied by elevated lipid peroxides. Glutathione peroxidase 4 (GPX4) regulates T0901317 induced ferroptotic sensitization, and its overexpression dramatically reverses the joint anticancer effect of T0901317 and FINs. Furthermore, xenograft model results highly confirmed the ferroptotic sensitization effect of T0901317 in vivo. In summary, our findings indicate that drug combination and ferroptosis induction strategies provide novel options for cancer therapy.

Corrigendum to "Efficacy and Safety of First-Line Immunotherapy in Combination with Chemotherapy for Patients with Extensive-Stage Small Cell Lung Cancer: A Systematic Review and Network Meta-Analysis".

[This corrects the article DOI: 10.1155/2020/2368164.].

Efficacy and Safety of First-Line Immunotherapy in Combination with Chemotherapy for Patients with Extensive-Stage Small Cell Lung Cancer: A Systematic Review and Network Meta-Analysis.

BACKGROUND: The prognosis of patients with extensive-stage small cell lung cancer (SCLC) is poor. Adding an immune checkpoint inhibitor (ICI) to chemotherapy may exert a synergistic effect and improve survival outcomes. However, for treatment-naive extensive-stage SCLC patients, the efficacy of immunotherapy in combination with cytotoxic chemotherapy remains controversial. OBJECTIVE: To evaluate the benefits and risks of the combination of immunotherapy and chemotherapy and to assess the comparative effectiveness of different first-line treatment strategies for extensive-stage SCLC. METHODS: PubMed, Web of Science, EMBASE, and Cochrane Library were searched for randomized clinical trials studying different immunotherapeutics for patients with previously untreated extensive-stage SCLC up to Feb 16, 2020. The primary outcomes were overall survival (OS) and progression-free survival (PFS), and the secondary outcomes were objective response rate (ORR), disease control rate (DCR), and adverse events. RESULTS: We identified 141 published records, and 4 studies (comprising 2202 patients) were included in the analysis. Immunotherapy (including ipilimumab, atezolizumab, and durvalumab) plus chemotherapy was associated with better OS (hazard ratio (HR) 0.84, 95% confidence interval (CI) 0.75-0.93; risk ratio (RR) 0.90, 95% CI 0.81-1.00) and PFS (HR: 0.81, 95% CI 0.74-0.88; RR 0.96, 95% CI 0.93-0.99) than placebo plus chemotherapy. The addition of immunotherapy to chemotherapy showed similar improvement in ORR, DCR, and adverse events versus placebo plus chemotherapy. On the surface under the cumulative ranking (SUCRA) analysis, the anti-PD-L1 agent, atezolizumab, had the highest likelihood of achieving improved OS (93.4%) and PFS (95.0%). CONCLUSION: In the first-line setting, combining immunotherapy with chemotherapy is better than standard chemotherapy in terms of OS and PFS. Across the eligible studies, PD-L1 inhibitors might be preferred. Further explorations of more ICIs in the first-line treatment for extensive-stage SCLC patients should be needed.

The efficacy and safety of PD-1/PD-L1 inhibitors in patients with recurrent or metastatic nasopharyngeal carcinoma: A systematic review and meta-analysis.

OBJECTIVES: There is currently no effective salvage therapeutic modality that improves the survival outcomes of patients with recurrent or metastatic nasopharyngeal carcinoma. However, the programmed cell death protein 1 (PD-1) and its ligand (PD-L1) inhibitors may provide clinical benefit for these advanced patients. MATERIALS AND METHODS: The databases, including PubMed, Web of Science, EMBASE and Cochrane Library, were systematically searched up to Nov 5, 2019. Data of objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) rate, overall survival (OS) rate, and drug-related adverse events were extracted and pooled meta-analyzed. RESULTS: From 71 search records, eight studies were included in the systematic review, of which three were eligible for final meta-analysis. In recurrent or metastatic nasopharyngeal carcinoma patients treated with anti-PD-1 therapy, the pooled ORR was 27% (95% confidence interval [CI] 19-36%), DCR was 63% (95% CI 50-75%), 6 months PFS rate was 49% (95% CI 40-58%), 1-year PFS rate was 25% (95% CI 19-32%), 1-year OS rate was 61% (95% CI 49-72%). The pooled incidences of any grade and grade ≥ 3 drug-related adverse events were 94% and 20% respectively. CONCLUSION: We present the aggregate response rates, survival rates and incidences of drug-related adverse events for recurrent or metastatic nasopharyngeal carcinoma patients receiving PD-1/PD-L1 blockage treatment, which could provide useful information for future design of clinical studies. There is a need for more randomized controlled studies with head-to-head comparison of PD-1/PD-L1 inhibitors and traditional chemotherapeutic strategies to enable better recommendations for optimal advanced nasopharyngeal carcinoma treatment.

The effects and safety of PD-1/PD-L1 inhibitors on head and neck cancer: A systematic review and meta-analysis.

BACKGROUND: Inhibitors of programmed cell death-1 (PD-1) and its ligand (PD-L1) have been increasingly used in head and neck cancer therapy and reported to improve the outcomes with an acceptable safety profile. This systematic review and meta-analysis was conducted to assess the benefit and risk of PD-1/PD-L1 inhibitors in patients with head and neck cancer. METHOD: The PubMed, Cochrane Library, EMBASE and Web of Science databases were systematically searched to find potentially eligible studies up to May 30, 2019. Primary outcomes were overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR) and adverse events. RESULTS: Overall, this analysis consisted of nine eligible studies, with two randomized controlled trials and seven single arm trials. In the treatment of recurrent or metastatic head and neck cancer, PD-1 inhibitors showed significantly lower relative risk of death than standard-of-care therapy (odds ratio [OR] = 0.60, 95% confidence interval [CI]: 0.44-0.82, I2  = 0%, P = .001). Programmed cell death-1 inhibitors also decreased the risk of disease progression, however, there was no statistically significant difference of PFS between the treatments (OR = 0.69, 95% CI: 0.48-1.01, I2  = 0%, P = .05). Subgroup analysis showed that human papillomavirus (HPV) positive patients had higher response rates than HPV negative patients in PD-1/PD-L1 inhibitors-treated population (ORR: 18.8% vs 12.2%; DCR: 42.8% vs 34.4%). The most common any-grade and grade ≥3 treatment-related adverse events were fatigue (14.7%, 95% CI: 12.3%-17.1%) and aspartate aminotransferase increased (1.6%, 95% CI: 0.3%-2.9%), respectively. CONCLUSION: Programmed cell death-1 inhibitors prolonged OS in comparison with standard-of-care therapy in recurrent or metastatic head and neck cancer patients. Human papillomavirus positive patients were superior to HPV negative patients in the treatment of PD-1/PD-L1 inhibitors. More phase III randomized controlled trials are warranted to confirm our findings.

LINC01939 inhibits the metastasis of gastric cancer by acting as a molecular sponge of miR-17-5p to regulate EGR2 expression.

Accumulating evidence have suggested that long noncoding RNAs (lncRNAs) are known to regulate diverse tumorigenic processes. Recently, a novel lncRNA LINC01939 was underexpressed and emerged as a tumor suppressive lncRNA in gastric cancer (GC). In this study, we aimed to investigate the biological function and molecular mechanism of LINC01939 in GC. We found that LINC01939 expression was significantly downregulated in GC tissues and cell lines. Low expression of LINC01939 was correlated with tumor metastasis and shorter survival in GC patients. Functionally, LINC01939 overexpression remarkably inhibited the invasion and migration of GC cells in vitro and in vivo. Mechanistically, LINC01939 regulated the expression of early growth response 2 (EGR2) protein by competitively binding to miR-17-5p. Upregulation of miR-17-5p reversed GC metastasis and EMT process caused by LINC01939 by rescue analysis. Taken together, these results suggested that LINC01939 repressed GC invasion and migration by functioning as a ceRNA for miR-17-5p to regulate EGR2 expression. Our findings provided a novel prognostic marker and therapeutic target for GC patients.

CLCA4 inhibits cell proliferation and invasion of hepatocellular carcinoma by suppressing epithelial-mesenchymal transition via PI3K/AKT signaling.

Calcium activated Chloride Channel A4 (CLCA4), as a tumor suppressor, was reported to contribute to the progression of several malignant tumors, yet little is known about the significance of CLCA4 in invasion and prognosis of hepatocellular carcinoma (HCC). CLCA4 expression was negatively correlated with tumor size, vascular invasion and TNM stage. Kaplan-Meier analysis showed that CLCA4 was an independent predictor for overall survival (OS) and time to recurrence (TTR). In addition, CLCA4 status could act as prognostic predictor in different risk of subgroups. Moreover, combination of CLCA4 and serum AFP could be a potential predictor for survival in HCC patients. Furthermore, CLCA4 may inhibit cell migration and invasion by suppressing epithelial-mesenchymal transition (EMT) via PI3K/ATK signaling. Knockdown of CLCA4 significantly increased the migration and invasion of HCC cells and changed the expression pattern of EMT markers and PI3K/AKT phosphorylation. An opposite expression pattern of EMT markers and PI3K/AKT phosphorylation was observed in CLCA4-transfected cells. Additionally, immunohistochemistry and RT-PCR results further confirmed this correlation. Taken together, CLCA4 contributes to migration and invasion by suppressing EMT via PI3K/ATK signaling and predicts favourable prognosis of HCC. CLCA4/AFP expression may help to distinguish different risks of HCC patients after hepatectomy.

Melatonin suppresses thyroid cancer growth and overcomes radioresistance via inhibition of p65 phosphorylation and induction of ROS.

Thyroid cancer is the most common endocrine carcinoma with increasing incidence worldwide and anaplastic subtypes are frequently associated with cancer related death. Radioresistance of thyroid cancer often leads to therapy failure and cancer-related death. In this study, we found that melatonin showed potent suppressive roles on NF-κB signaling via inhibition of p65 phosphorylation and generated redox stress in thyroid cancer including the anaplastic subtypes. Our data showed that melatonin significantly decreased cell viability, suppressed cell migration and induced apoptosis in thyroid cancer cell lines in vitro and impaired tumor growth in the subcutaneous mouse model in vivo. By contrast, irradiation of thyroid cancer cells resulted in elevated level of phosphorylated p65, which could be reversed by cotreatment with melatonin. Consequently, melatonin synergized with irradiation to induce cytotoxicity to thyroid cancer, especially in the undifferentiated subgroups. Taken together, our results suggest that melatonin may exert anti-tumor activities against thyroid carcinoma by inhibition of p65 phosphorylation and induction of reactive oxygen species. Radio-sensitization by melatonin may have clinical benefits in thyroid cancer.

HOXC6 predicts invasion and poor survival in hepatocellular carcinoma by driving epithelial-mesenchymal transition.

Aberrant expression of HOXC6 has been reported in several malignant tumors, yet little is known about the value of HOXC6 in invasion and prognosis of hepatocellular carcinoma (HCC). HOXC6 expression was positively correlated with high AFP level, liver cirrhosis, larger tumor, vascular invasion and BCLC stage. Kaplan-Meier analysis revealed that HOXC6 was an independent predictor for overall survival (OS) and time to recurrence (TTR). In addition, HOXC6 status could act as prognostic predictor in different risk subgroups. Moreover, HOXC6 maintained its prognostic value in different ability of invasiveness. Furthermore, combination of HOXC6 and serum AFP could be a potential predictor for survival in HCC patients. Additionally, further study showed that HOXC6 may promote invasion of HCC by driving epithelial-mesenchymal transition (EMT). Knockdown of HOXC6 significantly decreased the migration and invasion of HCC cells and changed the expression pattern of EMT markers. An opposite expression pattern of EMT markers was observed in HOXC6-transfected cells. In addition, immunohistochemistry and RT-PCR results further confirmed this correlation. In conclusion, HOXC6 contributes to invasion by inducing EMT pathway and predicts poor prognosis of HCC. HOXC6/AFP expression may help to distinguish the different risks of HCC patients after hepatectomy.

Redox-dependent modulation of metformin contributes to enhanced sensitivity of esophageal squamous cell carcinoma to cisplatin.

Glutathione is the major intracellular anti-oxidant against reactive oxygen species and serves as a detoxification essential. The anti-diabetic drug metformin has been showed to exert anti-tumor activity via modulation of redox homeostasis. In this study, we provided evidence that metformin inhibits proliferation and induces apoptosis of esophageal squamous cancer cells. Importantly, we found that metformin acts as pro-oxidant via depletion of intracellular glutathione. Co-treatment with metformin reversed the elevated intracellular glutathione induced by cisplatin and therefore enhanced the sensitivity to cisplatin in vitro and in vivo. Taken together, our data indicate that combination of metformin with cisplatin may represent a novel therapeutic strategy for esophageal squamous cell carcinoma treatment.

Low heme oxygenase-1 expression promotes gastric cancer cell apoptosis, inhibits proliferation and invasion, and correlates with increased overall survival in gastric cancer patients.

Heme oxygenase-1 (HO-1) plays a key role in anti-oxidation, anti-apoptosis, and anti-proliferation in various types of cancers. However, the relationship between HO-1 expression and gastric cancer development remains largely unknown. In this study, the protein expression of HO-1 in human gastric cancer was measured by immunohistochemistry on paraffin sections of 89 paired gastric carcinoma tissues and adjacent non-cancer tissues. The correlation of HO-1 expression with 5-year overall survival rate was estimated. The effects of decreased HO-1 expression by two strands of small interfered RNAs (siRNAs) on cell apoptosis, proliferation, and invasion of gastric cancer cell lines were examined by flow cytometry, the MTT assay, and the cell migration assay, respectively. High expression of HO-1 was detected in 11.2% (10/89) of gastric carcinoma tissues, compared with 1.1% (1/89) in matched adjacent normal tissues, and correlated with a decreased survival rate in gastric cancer patients. There were no significant correlations between HO-1 expression and clinical characteristics. Downregulation of HO-1 expression using two strands of siRNAs promoted apoptosis and inhibited the proliferation and invasion of two gastric cancer cell lines, SGC7901 and MKN-28 cells. This study demonstrated that HO-1 plays a vital role in the development of gastric cancer and may serve as a therapeutic target of this type of cancer.

GPX2 overexpression indicates poor prognosis in patients with hepatocellular carcinoma.

Glutathione peroxidase 2 has important role of tumor progression in lots of carcinomas, yet little is known about the prognosis of glutathione peroxidase 2 in hepatocellular carcinoma. Glutathione peroxidase 2 expression was assessed by immunohistochemistry in hepatocellular carcinoma tissues. The association between glutathione peroxidase 2 expression with clinicopathological/prognostic value was examined. Glutathione peroxidase 2 overexpression was correlated with alpha-fetoprotein level, larger tumor, BCLC stage, and tumor recurrence. Kaplan-Meier analysis showed that glutathione peroxidase 2 was an independent predictor for overall survival and time to recurrence. glutathione peroxidase 2 overexpression was correlated with poor prognosis in patient subgroups stratified by tumor size, differentiation, tumor-node-metastasis, and BCLC stage. Moreover, stratified analysis showed that tumor-node-metastasis stage-I patients with high glutathione peroxidase 2 expression had poor prognosis than those with low glutathione peroxidase 2 expression. Additionally, combination of glutathione peroxidase 2 and serum alpha-fetoprotein was correlated with prognosis in hepatocellular carcinoma. In conclusion, glutathione peroxidase 2 overexpression contributes to poor prognosis of hepatocellular carcinoma patients and helps to identify the high-risk hepatocellular carcinoma patients.

Upregulation of the long non-coding RNA PVT1 promotes esophageal squamous cell carcinoma progression by acting as a molecular sponge of miR-203 and LASP1.

Long non-coding RNAs are a group of non-coding RNAs longer than 200 nucleotides and possess diverse functions and exhibit exquisite cell-specific and developmental dynamic expression patterns. The role of the long non-coding RNA PVT1 in esophageal squamous cell carcinoma remains unsolved. Here, we showed that PVT1 expression is significantly up-regulated in ESCC tumor samples compared with their normal counterparts. Knockdown of PVT1 suppressed tumor growth in vitro and in vivo. Further studies revealed that silence of PVT1 lead to up-regulation of miR-203, and vice versa. Moreover, LASP1 was found to be downregulated after knockdown of PVT1 and overexpression of LASP1 attenuated the tumor-suppressive roles of PVT1 knockdown. Our results suggest that PVT1 promote ESCC progression via functioning as a molecular sponge for miR-203 and LASP1 and provide the first evidence of dysregulated PVT1/miR-203/LASP1 axis in ESCC.

LncRNA ANRIL is up-regulated in nasopharyngeal carcinoma and promotes the cancer progression via increasing proliferation, reprograming cell glucose metabolism and inducing side-population stem-like cancer cells.

Long noncoding RNAs play a vital role in diverse biological processes such as embryonic development, cell growth, and tumorigenesis. In this study, we report that LncRNA ANRIL, which encodes a 3834-nt RNA that contains 19 exons at the antisense orientation of the INK4B-ARF-INK4A gene cluster, generally up-regulated in nasopharyngeal carcinoma [1]. In a cohort of 88 NPC patients, ANRIL was highly expressed in advanced-stage cancer. Multivariate analyses revealed that ANRIL expression could serve as an independent predictor of overall survival (P = 0.027) and disease-free survival (P = 0.033). Further investigation showed that knockdown of ANRIL significantly repressed NPC cell proliferation and transformation. We also found that ANRIL could induce the percentage of side population cells (SP cells) in NPC. To meet the urgent needs of energy provision, ANRIL can also reprogram glucose metabolism via increasing glucose uptake for glycolysis, which was regulated by the mTOR signal pathway to affect the expression of essential genes in glycolysis. We concluded that ANRIL could promote NPC progression via increasing cell proliferation, reprograming cell glucose metabolism and inducing side-population stem-like cancer cells. Our results also suggested that ANRIL may serve as a novel diagnostic or prognostic biomarker and a candidate target for new therapies in NPC.

Low-dose hyper-radiosensitivity in human hepatocellular HepG2 cells is associated with Cdc25C-mediated G2/M cell cycle checkpoint control.

PURPOSE: Although the significance of cell cycle checkpoints in overcoming low-dose hyper-radiosensitivity (HRS) has been proposed, the underlying mechanism of HRS in human hepatocellular cells remains unclear. Therefore, the aim of this study was to characterize HRS inhuman hepatocellular HepG2 cells and to explore the molecular mechanism(s) mediating this response. MATERIALS AND METHODS: HepG2 cells were exposed to various single doses of γ radiation (from 0 Gy to 4 Gy), and then were assayed at subsequent time-points. Survival curves were then generated using a linear-quadratic (LQ) equation and a modified induced repair model (MIRM). The percentage of cells in the G1, G2/M, and S phases of the cell cycle were also examined using propidium iodide (PI) staining and flow cytometry. Levels of total cell division cyclin 25C (Cdc25C) and phosphorylated Cdc25C were examined by Western blotting. RESULTS: Low-dose γ radiation (<0.3 Gy) induced HRS in HepG2 cells, while doses of 0.3, 0.5, and 2.0 Gy γ radiation significantly arrested HepG2 cells in the G2/M phase. While total Cdc25C levels remained unchanged after irradiation, levels of phosphorylated Cdc25C markedly increased 6, 16, and 24 h after treatment with 0.5 or 2.0 Gy radiation, and they peaked after 16 h. The latter observation is consistent with the G2/M arrest that was detected following irradiation. CONCLUSIONS: These findings indicate that low-dose HRS in HepG2 cells may be associated with Cdc25C-mediated G2/M cell cycle checkpoint control.

Evaluation of HO-1 expression, cellular ROS production, cellular proliferation and cellular apoptosis in human esophageal squamous cell carcinoma tumors and cell lines.

Patients with esophageal squamous cell carcinoma (ESCC) have a poor prognosis. However, the related mechanisms are unclear, thus we investigated the expression of HO-1 in ESCC tissue and explored possible mechanisms of tumor progression. Expression of HO-1 was examined by immunohistochemistry in 143 ESCC tumors. The correlation of HO-1 with clinicopathological characteristics was also examined. Two human ESCC cell lines, TE-13 and Eca109 were studied. Silencing of cell line HO-1 by specific small interfering RNA (siRNA) was evaluated using real-time quantitative PCR. Cell line viability, apoptosis and intracellular levels of reactive oxygen species (ROS) after transfection were determined using MTT and flow cytometry, respectively. HO-1, Bax, Bcl-2 and A-caspase-3/-9 expression was evaluated using western blot analyses. We found that HO-1 was expressed in 58 of 143 ESCC tumors, mainly in the cytoplasm. There was a significant association between HO-1 expression and tumor grade (P<0.001). Knockdown of HO-1 expression in cell lines was associated with significantly decreased cellular proliferation (P<0.05) and a higher rate of apoptosis (P<0.001) 48 h after treatment. Treatment of the cell lines with the ROS inhibitor N-acetylcysteine abrogated this effect. Knockdown of HO-1 was associated with increased A-caspase-3 and -9 expression, but no change in Bax or Bcl-2 expression or Bax/Bcl-2 ratio was observed. Thus, the present study identified that ESCC tumors frequently expressed HO-1. Knockdown of HO-1 promoted apoptosis through activation of a ROS-mediated caspase apoptosis pathway.

Small hairpin RNA-mediated Krüppel-like factor 8 gene knockdown inhibits invasion of nasopharyngeal carcinoma.

The present study aimed to characterize the expression of Krüppel-like factor 8 (KLF8) in nasopahryngeal carcinoma (NPC) cell lines and determine its effect on tumor development and invasion following KLF8 gene knockdown by small hairpin RNA (shRNA). KLF8 expression in four NPC cell lines was examined by quantitative polymerase chain reaction (qPCR) and western blotting. KLF8 was knocked down in the SUNE1-5-8F/Sh-KLF8 cell line using shRNA, and the resulting stable cell line SUNE1-5-8F-sh-KLF8 was transplanted into nude mice in order to observe tumor formation and invasion. The results obtained from qPCR and western blotting revealed that, of the four NPC cell lines, KLF8 expression was lowest in the CNE-1 cells and highest in the SUNE1-5-8F cells. The tumor xenograft mouse models revealed that SUNE1-5-8F/Sh-KLF8 cells had a reduced ability for tumor formation and invasion compared with the control group. These results demonstrated for the first time that KLF8 modulates the formation and invasive ability of nasopharyngeal carcinoma.

EIF4EBP1 overexpression is associated with poor survival and disease progression in patients with hepatocellular carcinoma.

OBJECTIVE: EIF4EBP1 acts as a crucial effector in mTOR signaling pathway. Studies have suggested that EIF4EBP1 plays a critical role in carcinogenesis. However, the clinical significance and biological role of EIF4EBP1 in hepatocellular carcinoma (HCC) have not been elucidated. Therefore, we aimed to investigate the clinical significance of EIF4EBP1 in HCC. METHODS: Total 128 cases of HCCs were included in this study. EIF4EBP1 expression in HCC tissues was detected by qRT-PCR, Western blot and immunohistochemistry, respectively. Then the relationships between EIF4EBP1 expression and clinical features as well as survival were analyzed. RESULTS: The expression level of EIF4EBP1 mRNA is significantly higher in 60% (24/40) of fresh HCC tissues than that in the matched adjacent nontumor liver (NCL) tissues (P = 0.044). Similarly, EIF4EBP1 protein is notably upregulated in 8 HCC tissues (randomly selected from the 40 HCCs) measured by Western blot and is significantly increased in another 88 paraffin-embedded HCCs (53%, 47/88) by immunohistochemistry compared with the matched NCLs (P < 0.001). EIF4EBP1 protein expression in HCC tissues is significantly correlated with serum AFP (P = 0.003) and marginally significantly associated with pathological grade (P = 0.085), tumor number (P = 0.084), tumor embolus (P = 0.084) and capsulation (P = 0.073). Patients with higher EIF4EBP1 protein expression have a much worse 5-year overall survival (40.3% vs 73.6%) and 5-year disease-free survival (33.0% vs 49.0%) than those with low expression. Furthermore, Cox regression analysis shows that EIF4EBP1 protein is an independent prognostic factor for overall survival (HR, 2.285; 95% CI, 1.154-4.527; P = 0.018) and disease-free survival (HR, 1.901; 95% CI, 1.067-3.386; P = 0.029) in HCC patients. CONCLUSIONS: Our results demonstrate for the first time that EIF4EBP1 mRNA and protein are markedly up-regulated in HCC tissues, and the protein overexpression is significantly associated with poor survival and progression, which provide a potential new prognostic marker and therapeutic target for HCC patients.

Identification of PAQR3 as a new candidate tumor suppressor in hepatocellular carcinoma.

Progestin and adipoQ receptor family member III (PAQR3) is a regulator that negatively modulates the Ras/Raf/MEK/ERK signaling cascade and the GPCR Gßγ subunit signaling pathway. The role of PAQR3 in hepatocellular carcinoma (HCC) has not been elucidated. The present study investigated the expression of PAQR3 and its prognostic value in primary HCC patients. Furthermore, the functional aspects of PAQR3 were also studied using an in vitro cell model. PAQR3 expression was examined in paired HCC and adjacent noncancerous tissues using real-time quantitative RT-PCR (62 pairs) and western blotting (26 pairs). We also analyzed PAQR3 expression in 132 additional HCC samples by immunohistochemistry. The functional impact of PAQR3 on the proliferation and colony formation of an HCC cell line was analyzed by transfecting cells with a full-length PAQR3 expression vector or siRNA targeting PAQR3. The expression of PAQR3 was significantly decreased in the cancer tissues. Clinicopathological analyses showed that the expression of PAQR3 was significantly correlated with expression of serum α-fetoprotein (AFP), mitotic count, tumor size, histological grade and recurrence. Notably, Kaplan-Meier survival curves revealed a correlation between decreased expression of PAQR3 and the poor prognosis of HCC patients. Multivariate analyses showed that PAQR3 expression is an independent prognostic marker for overall and disease-free survival of HCC patients. Furthermore, restoring PAQR3 expression in HCC cells significantly diminished Hep3B cell proliferation and colony formation. Silencing PAQR3 expression in hepatic normal cell line LO2 significantly enhanced cell growth. PAQR3 may play an important role in the progression of HCC and serve as a potential candidate for the targeted therapy of HCC.

Overexpression of RPS6KB1 predicts worse prognosis in primary HCC patients.

RPS6KB1 (ribosomal protein S6 kinase, 70 kDa, polypeptide 1) plays a key role in regulating protein translation. The role of RPS6KB1 in HCC (hepatocellular carcinoma) has not been fully investigated. This study was undertaken to determine the clinicopathological features and prognostic value of RPS6KB1 in HCC. We examined RPS6KB1 expression in 30 paired liver cancer tissues and adjacent noncancerous tissues by reverse transcription real-time PCR and Western blotting. In addition, we analyzed RPS6KB1 expression in 87 HCC samples by immunohistochemistry. The expression of RPS6KB1 was significantly increased in cancer tissues. Clinicopathological analysis showed that the expression of RPS6KB1 was significantly correlated with tumor size, histopathologic classifications, and serum alpha-fetoprotein (AFP). Kaplan-Meier survival curves revealed that increased expression of RPS6KB1 correlated with poor prognosis of HCC patients. RPS6KB1 expression was an independent prognostic marker for overall survival of HCC patients by multivariate analysis. Our data suggest that RPS6KB1 may play an important role in the progression of HCC and could serve as a potential molecular target for HCC therapy.