LAPTM4B-35 is a novel prognostic factor of hepatocellular carcinoma

LAPTM4B-mediated hepatocellular carcinoma stem cell proliferation and MDSC migration: implications for HCC progression and sensitivity to PD-L1 monoclonal antibody therapy

In hepatocellular carcinoma (HCC), immunotherapy is vital for advanced-stage patients. However, diverse individual responses and tumor heterogeneity have resulted in heterogenous treatment outcomes. Our mechanistic investigations identified LAPTM4B as a crucial gene regulated by ETV1 (a transcription factor), especially in liver cancer stem cells (LCSCs). The influence of LAPTM4B on LCSCs is mediated via the Wnt1/c-Myc/β-catenin pathway. CXCL8 secretion by LAPTM4B drove myeloid-derived suppressor cell (MDSC) migration, inducing unfavorable patient prognosis. LAPTM4B affected PD-L1 receptor expression in tumor microenvironment and enhanced tumor suppression induced by PD-L1 monoclonal antibodies in HCC patients. LAPTM4B up-regulation is correlated with adverse outcomes in HCC patients, sensitizing them to PD-L1 monoclonal antibody therapy.

LAPTM4B-YAP loop feedback amplification enhances the stemness of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is highly heterogeneous, and stemness signatures are frequently elevated in HCC tumor cells to generate heterogeneous subtypes via multidirectional differentiation. However, the mechanisms affecting the regulation of stemness in HCC remain unclear. In this study, we identified that lysosome-associated protein transmembrane-4β (LAPTM4B) was significantly overexpressed in stem-like tumor cell populations with multidirectional differentiation potential at the single cell level, and verified that LAPTM4B was closely related to stemness of HCC using in vitro and in vivo experiments. Mechanistically, elevated LAPTM4B suppresses Yes-associated protein (YAP) phosphorylation and ubiquitination degradation. In turn, stabilized YAP localizes to the nucleus and binds to cAMP responsive element binding protein-1 (CREB1), which promotes transcription of LAPTM4B. Overall, our findings suggest that LAPTM4B forms a positive feedback loop with YAP, which maintains the stemness of HCC tumor cells and leads to an unfavorable prognosis for HCC patients.

Serum LAPTM4B as a Potential Diagnostic and Prognostic Biomarker for Breast Cancer

Background

Lysosome-associated protein transmembrane-4 beta (LAPTM4B) is an integral membrane protein overexpressed in various cancers and may function as a prognostic tumor marker. The present study is aimed at understanding the clinical significance of serum LAPTM4B in breast cancer (BC).

Methods

Serum LAPTM4B level was evaluated in 426 BC patients, 40 benign breast disease, and 80 healthy controls by ELISA. We used the receiver operator characteristic (ROC) curve to assess the diagnostic significance. 46 BC patients were recruited to monitor the dynamic change of serum LAPTM4B during adjuvant therapy (AT). In addition, sera from a subset of 330 patients undergoing AT, including anti-HER2 treatment, were collected to evaluate the association between LAPTM4B levels and AT efficacy. Descriptive and explorative statistical analyses were used to assess LAPTM4 B's potential as a diagnostic and prognostic marker in BC.

Results

Serum LAPTM4B level was significantly increased in BC patients than benign group and controls. It could well discriminate BC from healthy controls with diagnostic accuracy with an AUC of 0.912, a sensitivity of 85.9%, and a specificity of 83.8%. Compared with pre-AT, serum LAPTM4B concentration remarkably decreased after AT. In addition, patients in the invalid response group (PD + SD) showed higher LAPTM4B levels than the valid response group (PR + CR).

Conclusion

Our results proposed that serum LAPTM4B had a high diagnostic and prognostic impact as a circulating biomarker in BC.

LAPTM4B promotes the progression of bladder cancer by stimulating cell proliferation and invasion

Bladder cancer is a highly metastatic tumor and one of the most common malignant tumors originating in the urinary system. Due to the complicated etiology and lack of significant early symptoms, the diagnosis and treatment of bladder cancer is difficult. Lysosome-associated transmembrane protein 4β (LAPTM4B) was reported to be involved in the development and progression of several types of tumor, however, its potential effect on the development and metastasis of bladder cancer is still unclear. Immunohistochemistry was performed to detect the protein expression level of LAPTM4B in bladder cancer tissues and short hairpin RNAs targeting LAPTM4B were transfected into bladder cancer cells to knockdown its expression. MTT and colony formation assays were performed to detect cell proliferation, while wound healing and Transwell invasion assays were performed to detect cell migration and invasion, respectively. In addition, tumor growth assays were performed to confirm the effects of LAPTM4B in mice. The present study demonstrated that LAPTM4B was associated with the prognosis of patients with bladder cancer. In addition, LAPTM4B was associated with clinical characteristics, including tumor stage and recurrence. The results further showed that LAPTM4B knockdown could suppress the proliferation of bladder cancer cell lines. In addition, the migration and invasion of T24 and 5637 cells was suppressed following LAPTM4B knockdown in vitro. The in vivo data confirmed that knockdown of LAPTM4B markedly inhibited tumor growth and metastasis in mice. In summary, the results from the present study provide strong evidence of the effects of LAPTM4B in bladder cancer progression.

[Serum LAPTM4B-35 protein as a novel diagnostic marker for hepatocellular carcinoma]

OBJECTIVE

LAPTM4B-35 protein is one of the isoforms that are encoded by a cancer driver gene, LAPTM4B. This gene was primarily found and identified in our lab of Peking University School of Basic Medical Sciences. The LAPTM4B-35 protein and its encoded mRNA are significantly over-expressed in a variety of cancers, such as hepatocellular carcinoma (HCC), lung cancers (including non small-cell lung cancer and small-cell lung cancer), stomach cancer, colorectal carcinoma, pancreatic cancer, gallbladder cancer, cholangiocarcinoma, breast cancer, prostate cancer, ovarian cancer, cervical cancer, endometrial cancer, and so on. It has firmly demonstrated through lab experiments either in vivo or in vitro, as well as clinical studies that the over-expression of LAPTM4B-35 can promote cancer growth, metastasis, and multidrug resistance. Specially, the expressive level of LAPTM4B-35 is associa-ted with recurrence of HCC. The aim of this study is to identify the release of LAPTM4B-35 protein from hepatocellular carcinoma into blood of HCC patients and into the medium of cultured HCC cells, and to identify its possible form of LAPTM4B-35 protein existed in blood and cell culture medium, as well as to explore the possibility of LAPTM4B-35 protein as a novel HCC biomarker for diagnosis of HCC and prognosis of HCC patients.

METHODS

Immunobloting (Western blot) and enzyme-linked immunosorbent assay (ELISA) were used for identification of LAPTM4B-35 protein in the blood of HCC patients and normal individuals. Ultrafiltration and ultracentrifugation were used to isolate and purify exosomes from the culture medium of HCC cells.

RESULTS

LAPTM4B-35 protein existed in the blood from HCC patients and normal donors that were demonstrated through Western blot and ELISA. LAPTM4B-35 was also released into the culture medium of HCC cells in the form of exosomes. Preliminary experiments showed that the average and the median of LAPTM4B-35 protein level in the blood of HCC patients (n=43) were both significantly higher than that in the blood of normal donors (n=33) through sandwich ELISA.

CONCLUSION

It is promising that the LAPTM4B-35 protein which is released from HCC cells in the form of exosomes into their extraenvironment may be exploited as a novel cancer biomarker for HCC serological diagnosis.

A robust twelve-gene signature for prognosis prediction of hepatocellular carcinoma

Background

The prognosis of hepatocellular carcinoma (HCC) patients remains poor. Identifying prognostic markers to stratify HCC patients might help to improve their outcomes.

Methods

Six gene expression profiles (GSE121248, GSE84402, GSE65372, GSE51401, GSE45267 and GSE14520) were obtained for differentially expressed genes (DEGs) analysis between HCC tissues and non-tumor tissues. To identify the prognostic genes and establish risk score model, univariable Cox regression survival analysis and Lasso-penalized Cox regression analysis were performed based on the integrated DEGs by robust rank aggregation method. Then Kaplan-Meier and time-dependent receiver operating characteristic (ROC) curves were generated to validate the prognostic performance of risk score in training datasets and validation datasets. Multivariable Cox regression analysis was used to identify independent prognostic factors in liver cancer. A prognostic nomogram was constructed based on The Cancer Genome Atlas (TCGA) dataset. Finally, the correlation between DNA methylation and prognosis-related genes was analyzed.

Results

A twelve-gene signature including SPP1, KIF20A, HMMR, TPX2, LAPTM4B, TTK, MAGEA6, ANX10, LECT2, CYP2C9, RDH16 and LCAT was identified, and risk score was calculated by corresponding coefficients. The risk score model showed a strong diagnosis performance to distinguish HCC from normal samples. The HCC patients were stratified into high-risk and low-risk group based on the cutoff value of risk score. The Kaplan-Meier survival curves revealed significantly favorable overall survival in groups with lower risk score (P < 0.0001). Time-dependent ROC analysis showed well prognostic performance of the twelve-gene signature, which was comparable or superior to AJCC stage at predicting 1-, 3-, and 5-year overall survival. In addition, the twelve-gene signature was independent with other clinical factors and performed better in predicting overall survival after combining with age and AJCC stage by nomogram. Moreover, most of the prognostic twelve genes were negatively correlated with DNA methylation in HCC tissues, which SPP1 and LCAT were identified as the DNA methylation-driven genes.

Conclusions

We identified a twelve-gene signature as a robust marker with great potential for clinical application in risk stratification and overall survival prediction in HCC patients.

Genetic and molecular determinants of prostate cancer among Iranian patients: An update

Prostate cancer (PCa) is one of the most common age-related cancers among men. Various environmental and genetic factors are involved in the development and progression of PCa. In most cases, the primary symptoms of disease are not severe. Therefore, it is common for patients to be referred with severe clinical manifestations at advanced stages of disease. Since this malignancy is age related and Iran will face a significant increase in the number of seniors, it is expected that the prevalence of PCa among Iranian men will rise. PCa progression has been observed to be associated with genetic and ethnic factors. It may therefore be clinically useful to determine a panel of genetic markers, in addition to routine diagnostic methods, to detect tumors in the early stages. In the present review, we have summarized the reported genetic markers in PCa Iranian patients to pave the way for the determination of an ethnic specific genetic marker panel for the early detection of PCa. To understand the genetic and molecular biology of PCa among Iranians, we have categorized these genetic markers based on their cellular functions.

LAPTM4B-35 expression is associated with pathological grades and clinical stages in salivary adenoid cystic carcinoma

Salivary adenoid cystic carcinoma is one of the most common malignancies of the head and neck. The lysosome-associated protein transmembrane-4β gene (LAPTM4B) is a novel oncogene that has been found overexpressed in a number of clinically aggressive cancers. This study aimed to investigate the expression of the LAPTM4B-35 protein in normal salivary gland and salivary adenoid cystic carcinoma, a relatively indolent malignancy, and explore its clinicopathological significance in this malignancy. By immunohistochemical analysis, LAPTM4B-35 expression was evaluated in 106 cancer tissues, their adjacent non-cancerous tissues and five normal salivary glands. The correlation of LAPTM4B-35 expression with clinicopathological parameters was assessed using Chi-square or Fisher's exact test. The level of LAPTM4B-35 expression varied among different cell types of normal salivary glands. It was expressed at a fairly low level in serous and mucous acini, at low level in intercalated duct and excretory duct cells and moderately in secretory/striated ducts. In 50% of high grade tumor tissues tested, LAPTM4B-35 was markedly overexpressed. LAPTM4B-35 levels were significantly associated with histological grade and clinical stage. LAPTM4B-35 plays an important role in salivary adenoid cystic carcinoma and may serve as a diagnostic marker and a target for individualized therapy.

Induction of Lysosome-associated Protein Transmembrane 4 Beta via Sulfatase 2 Enhances Autophagic Flux in Liver Cancer Cells

Autophagy has been shown to be a key cellular event controlling tumor growth in different neoplasms including hepatocellular carcinoma (HCC). Although this biological role of autophagy has been clearly established, the mechanism underlying its regulation remains elusive. Here, we demonstrate a role of sulfatase 2 (SULF2), a 6‐O‐endosulfatase modulating various growth factors and cytokine‐related signaling pathways controlling tumor cell proliferation and survival, in the regulation of autophagy in HCC cells. SULF2 increased autophagosome formation, shown by increased LC3B‐II protein and green fluorescent protein–LC3 puncta. Increased fusion between autophagosomes and lysosomes/lysosomal enzymes, higher expression of lysosomal membrane protein, and an increase in autolysosomes were also shown by western blot, immunofluorescence, and electron microscopy of SULF2‐expressing cells, indicating enhanced autophagic flux. In contrast, RNA‐interference silencing of SULF2 in Huh7 cells induced lysosomal membrane permeabilization with diffuse cytosolic staining of cathepsin D and punctate staining of galectin‐3. Analysis of the mechanism showed that inhibition of lysosome‐associated protein transmembrane 4 beta (LAPTM4B), a gene induced by SULF2, resulted in decreased autophagosome formation, decreased fusion between autophagosomes and lysosomes, and increased lysosomal membrane permeabilization. Interestingly, down‐regulation of LAPTM4B also phenocopies the knockdown of SULF2, significantly reducing cell viability and colony formation. Conclusion: Our results demonstrate a role for SULF2 in the regulation of autophagic flux that is mediated through LAPTM4B induction in HCC cells, and provide a foundation for future translational efforts targeting autophagy in liver malignancies.

Preoperative Serum Insulin-Like Growth Factor 1 Level as a Prognostic Factor in Patients Undergoing Hepatic Resection for Hepatocellular Carcinoma

In this study, preoperative serum levels of insulin-like growth factor 1 (IGF-1) were determined in 216 hepatocellular carcinoma (HCC) patients who underwent hepatic resection to investigate a possible contribution of IGF-1 to the increased risk for HCC recurrence and mortality. During January 2010 and December 2013, 216 HCC patients receiving hepatectomy were recruited. The primary endpoint was the HCC recurrences within the 3-year follow-up. The secondary endpoint was all-cause mortality. The multivariate analyses with Cox regression model were applied to explore the clinical significance of IGF-1 serum levels and associated parameters on death and recurrence of HCC patients. The IGF-1 levels of included patients were determined, with a median value of 75.5 ng/mL (IQR, 40.3-93.0 ng/mL). The preoperative serum level of IGF-1 was negatively correlated with tumor size, Child-Pugh class, or tumor stage (P < 0.001 for all). In multivariate models comparing the first, second, and third quartiles with the fourth quartile of IGF-1, the levels of IGF-1 in Q1 and Q2 were associated with HCC recurrence, with an increased risk of 216% [hazard ratios (HR) = 3.16 (95% CI: 1.79-4.28)] and 106% [3.02 (1.36-3.11)]. Similarly, concentrations of IGF-1 in Q1 and Q2 were also related to all-cause mortality, with an increased recurrence risk of 238% [HR = 3.38 (95% CI: 1.85-4.36)] and 117% [3.02 (1.40-3.21)], respectively. Poor prognosis in HCC patients receiving hepatectomy could be indicated by low preoperative serum levels of IGF-1, which would be applied as a predictor.

LAPTM4B is a novel diagnostic and prognostic marker for lung adenocarcinoma and associated with mutant EGFR

Background

Lysosomal-associated protein transmembrane-4 beta (LAPTM4B), a novel oncogene, promotes tumorigenesis and may be a potential prognostic biomarker in several cancers. This study was to determine the clinical significance and biological roles of LAPTM4B in lung adenocarcinoma (LAC).

Methods

LAPTM4B expression was analyzed by immunohistochemistry (IHC) of 63 LAC tumors. Serum levels of LAPTM4B were measured by enzyme-linked immuosorbent assays (ELISA). The study included untreated group (n = 216), chemotherapy group (n = 29), chemotherapy efficacy group (n = 179), EGFR-TKIs group (n = 57) and 68 healthy controls. Statistical analysis was performed to explore the correlation between LAPTM4B expression and clinicopathological parameters in LAC. Kaplan-Meier analysis was performed to assess the prognostic significance of LAPTM4B in LAC. In vitro assays were performed to assess the biological roles of LAPTM4B in LAC cells. Western blotting assays were examined to identify the underlying pathways involved in the tumor-promoting role of LAPTM4B.

Results

We found LAPTM4B was upregulated in LAC tissues and high LAPTM4B expression was significantly correlated with poor prognosis. Serum LAPTM4B levels were significantly decreased after chemotherapy. Patients in invalid response group showed higher LAPTM4B levels than the valid response group. Overexpression of LAPTM4B promoted, while silencing of LAPTM4B inhibited proliferation, invasion and migration of LAC cells via PI3K/AKT and EMT signals. LAPTM4B expression level was associated with epidermal growth factor receptor (EGFR) gene mutations. In addition, LAPTM4B plays important roles in EGFR-promoted cell proliferation, migration and invasion and gefitinib-induced apoptosis.

Conclusions

Collectively, our data propose that LAPTM4B may be a cancer biomarker for LAC and a potential therapeutic target which facilitates the development of a novel therapeutic strategy against LAC.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5506-7) contains supplementary material, which is available to authorized users.

Clinical impact of circulating LAPTM4B-35 in pancreatic ductal adenocarcinoma

PURPOSE

LAPTM4B is upregulated in a wide range of cancers associated with poor prognosis. However, the clinical impact of LAPTM4B as diagnostic and prognostic marker in pancreatic ductal adenocarcinoma (PDAC) remains unknown. Thus, the aim of the present study was to investigate the expression of LAPTM4B as circulating marker in PDAC.

METHODS

Expression analysis of LAPTM4B-35 in pancreatic tissue and preoperative blood serum samples of 169 patients with PDAC UICC Stages I-IV (n = 98), chronic pancreatitis (n = 41), and healthy controls (n = 30) by immunohistochemistry, Western blot, and ELISA. Descriptive and explorative statistical analyses of LAPTM4B-35's potential as diagnostic and prognostic marker in PDAC.

RESULTS

Expression of LAPTM4B-35 was significantly increased in tumor tissue and corresponding blood serum samples of patients with PDAC (each p < 0.001) and it could well discriminate PDAC from healthy controls and chronic pancreatitis (p < 0.001; p = 0.0037). LAPTM4B-35 in combination with CA.19-9 outperforms the diagnostic accuracy with an AUC of 0.903 (p < 0.001), sensitivity of 82%, and specificity of 92%. Kaplan-Meier survival analysis revealed an improved overall survival in PDAC UICC I-IV with low expression of circulating LAPTM4B-35 (17 versus 10 months, p = 0.039) as well as an improved relapse-free survival in curatively treated PDAC UICC I-III (16 versus 10 months; p = 0.037). Multivariate overall and recurrence-free survival analyses identified LAPTM4B-35 as favorable prognostic factor in PDAC patients (HR 2.73, p = 0.021; HR 3.29, p = 0.003).

CONCLUSION

LAPTM4B-35 is significantly deregulated in PDAC with high diagnostic and prognostic impact as circulating tumor marker.

Prognostic Values of LAPTM4B-35 in Human Cancer: A Meta-analysis

Background: Lysosome-associated protein transmembrane-4β-35(LAPTM4B-35) has been observed overexpressed in multiple malignant tumors. However, the prognostic value of LAPTM4B-35 remains controversial. Therefore, we conducted a meta-analysis to evaluate the prognostic value of LAPTM4B-35 in human cancers. Methods: The relevant publications were obtained by systematically searching the PubMed, Web of Science, Embase, Wanfang, and China National Knowledge Infrastructure (CNKI) databases. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated for the prognosis value of LAPTM4B-35 for cancer patient. Results: Our result suggest that LAPTM4B-35 overexpression is significantly associated with poor overall survival (OS) (HR = 2.49, 95% CI = 1.87-3.32, p < 0.001), disease-free survival (DFS) (HR = 2.43, 95% CI = 1.35-4.35, p = 0.003), and progression-free survival (PFS) (HR = 4.12, 95% CI = 2.30-7.37, p < 0.001). Moreover, subgroup analysis revealed significant association with poor OS in lung (HR = 2.05, 95% CI = 1.37-3.06, p < 0.001), gastric carcinoma (HR = 1.88, 95% CI = 1.01-3.50, p < 0.047) and ovarian cancer (HR = 4.94, 95% CI = 1.44-16.94, p = 0.011). Conclusion: LAPTM4B-35 may be a novel predictive biomarker and a potential target for treatment.

Expression signature of lysosomal-associated transmembrane protein 4B in hepatitis C virus-induced hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma is a lethal disease worldwide and therefore the establishment of novel diagnostic biomarkers is imperative. In this study, it was hypothesized that an abnormal expression of the lysosomal-associated protein transmembrane 4 beta ( LAPTM4B) gene is crucial in the pathogenesis of hepatitis C virus-mediated hepatocellular carcinoma; hence we investigated the expression profile of LAPTM4B in hepatitis C virus-induced hepatocellular carcinoma.

METHODS

A group of 189 consecutive patients (hepatitis C virus-related hepatocellular carcinoma as tumor cases; n=93, hepatitis C virus-related cirrhotics as disease controls; n=96) opting for living donor liver transplantation as a therapeutic surgical regimen were recruited with informed consent. Additionally, paired adjacent non-tumorous tissues (n=93) obtained from cases were also included. Serum LAPTM4B protein concentrations were assessed by third-generation enzyme-linked immunosorbent assay and LAPTM4B mRNA, and protein expressions at tissue level were determined by quantitative real time reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemistry techniques, respectively.

RESULTS

LAPTM4B protein concentrations in sera of patients were higher ( p<0.001) in tumor cases (1.25±0.25 ng/ml) compared to disease controls (0.53±0.28 ng/ml). Our study also depicts positive clinicopathological correlations between alpha-fetoprotein titers (b=0.65; p<0.001), quantitative hepatitis C virus RNA copies (b=0.33; p<0.001), and LAPTM4B protein concentrations, all in sera of patients. In addition, qRT-PCR and immunohistochemistry analyses revealed a significantly higher ( p<0.05) tissue LAPTM4B mRNA and protein expression, respectively, in tumor cases rather than in non-tumorous tissues and disease controls.

CONCLUSIONS

Together, our results illustrate the LAPTM4B gene as a diagnostic biomarker in patients with hepatocellular carcinoma having documented evidence of chronic hepatitis C virus infection.

The High-Sensitivity C-Reactive Protein/Albumin Ratio Predicts Long-Term Oncologic Outcomes after Curative Resection for Hepatocellular Carcinoma

High-sensitivity C-reactive protein (hsCRP) is a prognostic factor for hepatocellular carcinoma (HCC), while albumin is known to be a disease severity index of the malnutrition status in HCC patients. The present study investigated the association between postoperative hsCRP/albumin ratio and both overall survival (OS) and recurrence-free survival (RFS) following HCC surgery. This retrospective observational study examined the medical records of 389 patients who underwent resection for HCC between 2004 and 2013. Postoperative day 0⁻1 hsCRP/albumin ratio was collected, and the optimal postoperative mortality cut-off point was derived using receiver operating characteristics (ROC) analysis. A postoperative hsCRP/albumin ratio increase of 1.0 was associated with a 1.171-fold increase in mortality (hazard ratio (HR): 1.171, 95% confidence interval (CI): 1.072⁻1.278, p < 0.001) and a 1.19-fold increase in recurrence (HR: 1.190, 95% CI: 1.108⁻1.278, p < 0.001). The hsCRP/albumin ratio cut-off point was found to be 0.625 and 0.500. When patients were grouped by this cut-off point, the >0.625 group showed a 2.257-fold increase in mortality (HR: 2.257, 95% CI: 1.470⁻3.466, p < 0.001), and the >0.500 group showed a 1.518-fold increase in recurrence (HR: 1.518, 95% CI: 1.125⁻2.050, p = 0.006).

Targeting a novel cancer-driving protein (LAPTM4B-35) by a small molecule (ETS) to inhibit cancer growth and metastasis

Our previous studies demonstrated that LAPTM4B-35 is overexpressed in a variety of solid cancers including hepatocellular carcinoma (HCC), and is an independent factor for prognosis. LAPTM4B-35 overexpression causes carcinogenesis and enhances cancer growth, metastasis and multidrug resistance, and thus may be a candidate for therapeutic targeting. The present study shows ethylglyoxal bisthiosemicarbazon (ETS) has effective anticancer activity through LAPTM4B-35 targeting. Bel-7402 and HepG2 cell lines from human HCC were used as cell models in which LAPTM4B-35 is highly expressed, and a human fetal liver cell line was used as a control. The results showed ETS has a specific and pronounced lethal effect on HCC cells, but not on fetal liver cells in culture. ETS also attenuated growth and metastasis of human HCC xenograft in nude mice, and extended the life span of mice with HCC. ETS induced HCC cell apoptosis, and upregulated a large number of proapoptotic genes and downregulated antiapoptotic genes. When endogenous overexpression of LAPTM4B-35 was knocked down with RNAi, the killing effect of ETS on HepG2 cells was significantly attenuated. ETS also inhibited phosphorylation of LAPTM4B-35 Tyr285, which involves in activation of the PI3K/Akt signaling pathway induced by LAPTM4B-35 overexpression. In addition, the induction of alterations in quantity of c-Myc, Bcl-2, Bax, cyclinD1 and Akt-p molecules in HepG2 cells by LAPTM4B-35 overexpression could be reversed by ETS.

CONCLUSION

ETS is a promising candidate for treatment of HCC through LAPTM4B-35 protein targeting.

The Transcription Factor AP4 Promotes Oncogenic Phenotypes and Cisplatin Resistance by Regulating LAPTM4B Expression

Lysosomal-associated protein transmembrane-4 beta (LAPTM4B) is a novel oncogene, whose overexpression is involved in cancer occurrence and progression. However, the mechanism of LAPTM4B transcriptional regulation remains unclear. In this study, the results of transcription factor (TF) profiling plate arrays indicated that AP4 was a potential transcription factor regulating LAPTM4B expression. LAPTM4B was positively correlated with AP4 and they were both associated with poor overall and disease-free survival. Luciferase and electrophoretic mobility shift assay assays confirmed that AP4 directly bound to the polymorphism region of LAPTM4B promoter and modulated its transcription. Functionally, AP4 promoted cell proliferation, migration, invasion, and assisted drug resistance in part through upregulation of LAPTM4B. Taken together, these findings identify LAPTM4B as a direct AP4 target gene and the interaction of AP4 and LAPTM4B plays an important role in breast cancer progression.Implications: This study demonstrates that AP4 promotes cell growth, migration, invasion, and cisplatin resistance through upregulation of LAPTM4B expression, thus representing an attractive therapeutic target for breast cancer. Mol Cancer Res; 16(5); 857-68. ©2018 AACR.

Correlation of lysosome-associated protein transmembrane-4β gene overexpression with the malignant phenotypes of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and rapidly fatal malignancies, for which hepatitis B virus (HBV) chronic infection constitutes a major risk factor. The lysosome-associated protein transmembrane-4 β gene (LAPTM4B) is a recently identified gene that was found to be overexpressed in several types of cancer. However, the role of LAPTM4B in HCC tumorigenesis and progression has not been clearly determined. The present study demonstrated that the mRNA as well as the protein levels of LAPTM4B were significantly upregulated in HCC specimens. Patients with higher levels of LAPTM4B mRNA in their HCC tissues tended to be of a younger age, HBsAg+, with an advanced Barcelona Clinic Liver Cancer stage. Moreover, LAPTM4B mRNA expression was positively associated with serum α -fetoprotein levels. We also observed that LAPTM4B was able to promote HCC cell proliferation, migration and invasion in vitro. In conclusion, our results indicated that LAPTM4B plays an important role in the promotion of hepatocarcinogenesis and cancer progression and may serve as a biomarker for the diagnosis and monitoring of HCC.

Lysosome-associated protein transmembrane4β is involved in multidrug resistance processes of colorectal cancer

Colorectal cancer (CRC) is one of the most common reasons for cancer-associated mortality worldwide. The present study aimed to investigate the drug resistance mechanism of the oxaliplatin (OXA)-resistant HT-29 cell line (HT-29/L-OHP) and examine the expression of lysosome-associated protein transmembrane 4β (LAPTM4β), a drug resistance-associated gene. In the present study, a drug concentration gradient method was used to establish the drug-resistant HT-29/L-OHP cell line. Cell apoptosis was analyzed by flow cytometry. LAPTM4β mRNA expression was examined by reverse transcription-quantitative polymerase chain reaction analysis and LAPTM4β-35 expression was examined by western blot analysis. Cell morphology of the HT-29/L-OHP drug-resistant cell line was examined. The results indicated that the intercellular space among HT-29 cells was small, with aggregative growth while the intercellular space among HT-29/L-OHP cells was large, with scattered growth. The apoptotic rate in HT-29/L-OHP cells (11.7%) was significantly lower compared with that in HT-29 cells (17.7%) (P<0.05). LAPTM4β mRNA expression in HT-29/L-OHP cells was significantly increased compared with that in HT-29 cells (P<0.05). The relative expression of LAPTM4β-35 protein in HT-29/L-OHP cells was significantly higher compared with that inHT-29 cells (P<0.05). In conclusion, LAPTM4β may be involved in the multidrug resistance processes of CRC. Therefore, LAPTM4β may serve as a novel biomarker for drug resistance of CRC.

Association of lysosomal protein transmembrane 4 beta gene polymorphism with pancreatic carcinoma susceptibility in the Chinese population

Pancreatic carcinoma is an aggressive malignancy with particularly low 5-year survival rate. In order to improve the dismal survival rate, identification of new potential susceptibility risk factors for the prevention and early detection of pancreatic carcinoma is of utmost importance. Lysosomal protein transmembrane 4 beta has two alleles designated as LAPTM4B*1 and LAPTM4B*2. The aim of this study was to investigate the association between lysosomal protein transmembrane 4 beta gene polymorphism and the risk of pancreatic carcinoma in China. A population-based case-control analysis was performed in 233 patients with pancreatic carcinoma and 842 control subjects. The genotypes of lysosomal protein transmembrane 4 beta were determined by utilizing polymerase chain reaction based on specific primers. The χ2 test was used to analyze the differences of categorical variables and Hardy-Weinberg equilibrium. Odds ratio and 95% confidence intervals were computed using an unconditional logistic regression model. A significant difference in the frequency of LAPTM4B*2 was observed between the patients and the controls (33.05% vs 27.55%, p = 0.03). LAPTM4B*2 had a 1.33-fold (95% confidence interval: 1.04-1.71) higher risk for developing pancreatic carcinoma when compared with LAPTM4B*1 carriers. We found that the frequency of LAPTM4B*1/2 + *2/2 in pancreatic carcinoma group was higher than that in the control group (57.94% vs 48.34%, p = 0.01). However, no significant association was observed between lysosomal protein transmembrane 4 beta genotypes and gender, age, family history of cancer, smoking/alcohol status, histopathological differentiation, lymph node metastasis, clinical stage, or serum cancer antigen 19-9 level. These findings indicate that the LAPTM4B*2 allele is associated with the high risk of pancreatic carcinoma and carrying LAPTM4B*2 may be a susceptible factor to Chinese pancreatic carcinoma patients.

LAPTM4B-35 is a novel prognostic factor for glioblastoma

Lysosome-associated protein transmembrane-4 beta (LAPTM4B)-35, a newly identified cancer-associated gene, is overexpressed in a wide variety of malignant tumors. However, studies of its expression and role in glioma have not yet been reported. This study aimed to investigate the expression and the role of LAPTM4B-35 in glioma and to assess its value as a prognostic factor. Seventy-seven glioma cases (Grade II in 18 patients, Grade III in 16 and Grade IV in 43) were immunohistochemically examined for LAPTM4B-35, pAkt, factor VIII and Ki-67 expressions. The LAPTM4B-35 expression score of Grade II gliomas was lower than those of Grade III-IV gliomas (p < 0.05), while the difference between Grade III and IV gliomas was not statistically significant. Of the 43 patients with glioblastoma (GBM), 27 (62.8%) had high LAPTM4B-35 expression, which was associated with high tumor micro-vessel density and pAkt activation. The median progression-free survival (PFS) of GBM patients with high LAPTM4B-35 expression was 5.13 months, significantly shorter than that of those with low LAPTM4B-35 expression (12.0 months, p < 0.0001). The median overall survival (OS) of GBM patients with high LAPTM4B-35 expression was 12.5 months, again significantly shorter than that of those with low LAPTM4B-35 expression (29.6 months, p < 0.0001). Multivariate analysis indicated LAPTM4B-35 to be an independent prognostic factor for PFS and OS of GBM patients. Our findings show LAPTM4B-35 to be strongly associated with tumor proliferation, tumor angiogenesis and poor outcomes of GBM patients, suggesting LAPTM4B-35 to potentially be applicable as a novel prognostic marker and even to possibly play a role in improving GBM treatment.

LAPTM4B: an oncogene in various solid tumors and its functions

The oncogene Lysosome-associated protein transmembrane-4β (LAPTM4B) gene was identified, and the polymorphism region in the 5′-UTR of this gene was certified to be associated with tumor susceptibility. LAPTM4B-35 protein was found to be highly expressed in various solid tumors and could be a poor prognosis marker. The functions of LAPTM4B in solid tumors were also explored. It is suggested that LAPTM4B could promote the proliferation of tumor cells, boost invasion and metastasis, resist apoptosis, initiate autophagy and assist drug resistance.

Thioredoxin reductase: a novel, independent prognostic marker in patients with hepatocellular carcinoma

Here we found that hepatocellular carcinoma (HCC) patients with recurrence outcome and nonsurvivors had significantly increased thioredoxin reductase (TrxR) serum levels on reoperation (P < 0.0001 and P < 0.0001). Multivariate regression analysis adjusted for common risk factors showed that TrxR was an independent predictor of recurrence (hazard ratios [HR] = 4.19; 95% confidence intervals [CI]: 3.21-7.08) and overall survival (HR = 5.56; 95% CI: 3.42-10.21). The area under the receiver operating characteristic curve of TrxR was 0.837 (95% CI, 0.794-0.881) for recurrence outcome and 0.901 (95% CI, 0.869-0.933) for mortality, which was superior to high-sensitivity-C-reactive protein and a-fetoprotein (P < 0.001). The preoperative serum TrxR level is an independent and significant indicator predictive of poor prognosis and early recurrence in patients with HCC, which offering reliable information for predicting survival.

Association between LAPTM4B gene polymorphism and prostate cancer susceptibility in an Iranian population

Lysosome associated protein transmembrane 4 β (LAPTM4B) is an oncogene associated with many human cancers. In the present study we aimed to examine the possible association between LAPTM4B polymorphism and risk of prostate cancer (PCa) in an Iranian population. This case control study was performed on 168 patients with PCa and 176 controls with benign prostatic hyperplasia (BPH). Genomic DNA was extracted from whole blood and LAPTM4B genotypes were identified by polymerase chain reaction. The distributions of LAPTM4B genotypes were significantly different between PCa patients (60.7% for *1/1, 32.8% for *1/2, and 6.5% for *2/2) and controls (44.9% for *1/1, 49.4% for *1/2, and 5.7% for *2/2). Both the *1/2 and *1/2+*2/2 genotypes significantly decreased the risk of PCa compared with the *1/1 genotype (OR = 49, 95% CI = 0.31-0.77, p = 0.002 and OR = 0.53, 95% CI = 0.34-0.81, p = 0.004, respectively). The minor allele (LAPTM4B*2) was associated with a decreased risk of PCa compared with the LAPTM4B*1 allele (OR = 0.68, 95% CI = 0.48-0.96, p = 0.031). Moreover, LAPTM4B polymorphism was not associated with clinicopathological characteristics of PCa patients. The results of this study showed that LAPTM4B*2 was associated with a decreased risk of PCa but the clinicopathological characteristics of PCa were not linked to LAPTM4B polymorphism. Further studies with larger sample sizes and different ethnicities are needed to confirm our findings.

Elevated Preoperative Serum Hs-CRP Level as a Prognostic Factor in Patients Who Underwent Resection for Hepatocellular Carcinoma

To evaluate the effects of preoperative highly sensitive C-reactive protein (Hs-CRP) in serum on the prognostic outcomes of patients with hepatocellular carcinoma (HCC) following hepatic resection in Chinese samples.From January 2004 to December 2008, a total of 624 consecutive HCC patients who underwent hepatic resection were incorporated. Serum levels of Hs-CRP were tested at preoperation via a collection of venous blood samples. Survival analyses adopted the univariate and multivariate analyses.In our study, among the 624 screened HCC patients, 516 patients were eventually incorporated and completed follow-up. Positive correlations were found regarding preoperative serum Hs-CRP level and tumor size, Child-Pugh class, or tumor stage (all P < 0.0001). Patients with recurrence outcomes and nonsurvivors had increased Hs-CRP levels at preoperation (both P < 0.0001). When compared to the Hs-CRP-normal group, the overall survival (OS) and recurrence-free survival rates were evidently decreased in the Hs-CRP-elevated group. Further, preoperative serum Hs-CRP level might be having possible prediction effect regarding survival and recurrence of HCC patients after hepatic section in the multivariate analysis.Preoperative increased serum Hs-CRP level was an independent prognostic indicator in patients with HCC following hepatic resection in Chinese samples.

Predictive significance of combined LAPTM4B and VEGF expression in patients with cervical cancer

Lysosome-associated protein transmembrane 4ß-35 (LAPTM4B-35) is overexpressed in several solid malignancies. This study determines the expression level of LAPTM4B-35 in the cervical cancer during tumor development and progression. The present study investigated the clinicopathological significance of the coexpression of LAPTM4B-35 and VEGF in patients with cervical cancer. Immunohistochemistry was used to evaluate the expression of LAPTM4B-35 and VEGF in 62 cervical intraepithelial neoplasia (CIN) and 226 cervical carcinoma in comparison with 45 normal cervical specimens. The correlation of combined LAPTM4B-35 and VEGF with clinicopathologic characteristics was analyzed using a chi-squared test. Patient survival was determined using Kaplan-Meier method and log-rank test. A Cox regression analysis was performed to determine the prognostic significance of the factors. Combined LAPTM4B-35 and VEGF expression was significantly associated with FIGO stage (P = 0.014), tumor histologic grade (P = 0.033), lymph node metastasis (P = 0.045), and recurrence (P = 0.010). Kaplan-Meier survival analysis showed that patients with cervical cancer expressing both LAPTM4B-35 and VEGF exhibited both poor overall survival (OS) and disease-free survival (DFS) (P = 0.015 and P = 0.016, respectively). Cox analysis demonstrated that combined LAPTM4B-35 and VEGF expression was an independent factor for both OS and DFS (P = 0.015 and P = 0.016, respectively). Overexpression of LAPTM4B-35combined with positive VEGF expression may serve as a new biological marker to predict the prognosis of cervical carcinoma patients.

LAPTM4B is associated with poor prognosis in NSCLC and promotes the NRF2-mediated stress response pathway in lung cancer cells

We recently demonstrated that lysosomal protein transmembrane 4 beta (LAPTM4B) is elevated in non-small cell lung cancers (NSCLCs) and in the surrounding premalignant airway field of cancerization. In the present study, we sought to begin to understand the relevance of LAPTM4B expression and signaling to NSCLC pathogenesis. In situ hybridization analysis of LAPTM4B transcript in tissue microarrays comprised of 368 NSCLCs demonstrated that LAPTM4B expression was significantly increased in smoker compared to non-smoker lung adenocarcinoma tumors (P < 0.001) and was significantly associated with poor overall survival (P < 0.05) in adenocarcinoma patients. Knockdown of LAPTM4B expression inhibited cell growth, induced cellular apoptosis and decreased cellular autophagy in serum starved lung cancer cells. Expression profiling coupled with pathways analysis revealed decreased activation of the nuclear factor erythroid 2-like 2 (NRF2) stress response pathway following LAPTM4B knockdown. Further analysis demonstrated that LAPTM4B augmented the expression and nuclear translocation of the NRF2 transcription factor following serum deprivation as well as increased the expression of NRF2 target genes such as heme oxygenase 1/HMOX1). Our study points to the relevance of LAPTM4B expression to NSCLC pathogenesis as well as to the probable role of LAPTM4B/NRF2 signaling in promoting lung cancer cell survival.

Lysosomal-associated Transmembrane Protein 4B (LAPTM4B) Decreases Transforming Growth Factor β1 (TGF-β1) Production in Human Regulatory T Cells

Production of active TGF-β1 is one mechanism by which human regulatory T cells (Tregs) suppress immune responses. This production is regulated by glycoprotein A repetitions predominant (GARP), a transmembrane protein present on stimulated Tregs but not on other T lymphocytes (Th and CTLs). GARP forms disulfide bonds with proTGF-β1, favors its cleavage into latent inactive TGF-β1, induces the secretion and surface presentation of GARP·latent TGF-β1 complexes, and is required for activation of the cytokine in Tregs. We explored whether additional Treg-specific protein(s) associated with GARP·TGF-β1 complexes regulate TGF-β1 production in Tregs. We searched for such proteins by yeast two-hybrid assay, using GARP as a bait to screen a human Treg cDNA library. We identified lysosomal-associated transmembrane protein 4B (LAPTM4B), which interacts with GARP in mammalian cells and is expressed at higher levels in Tregs than in Th cells. LAPTM4B decreases cleavage of proTGF-β1, secretion of soluble latent TGF-β1, and surface presentation of GARP·TGF-β1 complexes by Tregs but does not contribute to TGF-β1 activation. Therefore, LAPTM4B binds to GARP and is a negative regulator of TGF-β1 production in human Tregs. It may play a role in the control of immune responses by decreasing Treg immunosuppression.

LAPTM4B-35, a cancer-related gene, is associated with poor prognosis in TNM stages I-III gastric cancer patients

Background

Lysosome-associated transmembrane protein 4β-35 (LAPTM4B-35), a member of the mammalian 4-tetratransmembrane spanning protein superfamily, has been reported to be overexpressed in several cancers. However the expression of LAPTM4B-35 and its role in the progression of gastric cancer (GC) remains unknown. The aim of this study was to investigate LAPTM4B-35 expression in GC, its potential relevance to clinicopathologic parameters and role of LAPTM4B-35 during gastric carcinogenesis.

Methods

In the present study, paraffin-embedded specimens with GC (n = 240, including 180 paired specimens) and 24 paired fresh frozen tissues were analyzed. qRT-PCR and immunohistochemistry (IHC) were used to analyze the expression of LAPTM4B-35 in GC. The effects of LAPTM4B-35 on GC cell proliferation, migration and invasion were determined by overexpression and knockdown assays.

Results

IHC showed that LAPTM4B-35 was expressed in 68.3% (123/180) of GC tissues, while in 16.1% (29/180) of their paired adjacent noncancerous gastric tissues (P = 0.000). LAPTM4B-35 mRNA levels in GC tissues were also significantly elevated when compared with their paired adjacent noncancerous tissues (P = 0.017). Overexpression of LAPTM4B-35 was significantly associated with degree of differentiation, depth of invasion, lymphovascular invasion and lymph node metastasis (P<0.05). Kaplan-Meier survival curves revealed that patients with LAPTM4B-35 expression had a significant decrease in overall survival (OS) in stages I-III GC patients (P = 0.006). Multivariate analysis showed high expression of LAPTM4B-35 was an independent prognostic factor for OS in stage I-III GC patients (P = 0.025).

Conclusion

These findings indicate that LAPTM4B-35 overexpression may be related to GC progression and poor prognosis, and thus may serve as a new prediction marker of prognosis in GC patients.

Lysosomal-associated protein transmembrane 4 Beta-35 overexpression is a novel independent prognostic marker for gastric carcinoma

OBJECTIVE

The purpose of this work was to analyze the relationships between the expression status of Lysosomal-associated protein transmembrane-4 beta 35 (LAPTM4B-35) in cancerous tissues and clinicopathological characteristics and prognosis of the patients with gastric carcinoma (GC).

METHODS

The GC samples from 157 patients in a discovery cohort and 148 patients in a testing cohort with follow-up data were used to validate the feasibility of expression of LAPTM4B-35 protein in predicting GC prognosis. Immunohistochemical staining was used to determine the expression of LAPTM4B-35 protein in precancerous gastric lesions and gastric carcinomas. The correlation between the expression of LAPTM4B-35 and clinicopathologic characteristics of patients with gastric carcinoma was analyzed using chi-square test. Univariate and multivariate analyses were performed to determine the association between LAPTM4B-35 expression and prognosis.

RESULTS

LAPTM4B-35 expression was increased steadily in sequential stages of precancerous gastric lesions. Positive LAPTM4B-35 expression was more frequently detected in patients with distant metastasis (P = 0.023) and III+IV TNM stages (P = 0.042) in the discovery cohort. Kaplan-Meier survival curves and univariate analysis showed that expression of LAPTM4B-35 had a significant impact on overall survival of patients with gastric carcinoma in discovery cohort (P<0.001) and testing cohort (P = 0.001). LAPTM4B-35 expression was an independent prognostic indicator for the overall survival of patients with gastric carcinoma in both cohorts.

CONCLUSIONS

The present research demonstrated that LAPTM4B-35 over-expression was an independent factor in gastric carcinoma prognosis. LAPTM4B gene may be a useful target of interventions slowing the progression of precancerous gastric lesions and a new therapy method to improve the prognosis of gastric carcinoma.

Relationship Between LAPTM4B Gene Polymorphism and Susceptibility of Malignant Melanoma in Chinese Patients

Lysosomal-associated protein transmembrane 4 beta (LAPTM4B) is known as an oncogene associated with many human malignant tumors. There are two alleles of the gene, LAPTM4B*1 and LAPTM4B*2. Previous studies have shown that LAPTM4B polymorphism contributes to the risk of many cancers. This case-control study was to investigate the relationship between LAPTM4B gene polymorphism and susceptibility of malignant melanoma. The genotypes of LAPTM4B were determined in 617 control subjects and 220 patients with malignant melanoma by utilizing polymerase chain reaction based on specific primers. The genotypic distribution of LAPTM4B and Hardy–Weinberg equilibrium were analyzed by χ² test. Odds ratio and 95% confidence interval was calculated by unconditional logistic regression. The distributions of LAPTM4B genotypes were significantly different between melanoma patients (45.9% for *1/1, 46.4% for *1/2 and 7.7 for *2/2) and controls (54.5% for *1/1, 39.9% for *1/2 and 5.7 for *2/2). LAPTM4B *1/2 and LAPTM4B *2/2 had a 1.396-fold and 1.619-fold higher risk for melanoma occurrence than *1/1, and subjects with LAPTM4B*2 have a 1.308-fold higher risk than LAPTM4B*1 carriers. No association between LAPTM4B genotypes and gender, age, subtype, Clark level of invasion, Breslow thickness, ulceration, clinical stage, and C-KIT, BRAF gene mutation status was observed. LAPTM4B*2 is associated with the high risk of malignant melanoma and carrying LAPTM4B *2 may be a susceptible factor to Chinese melanoma patients.

Association between LAPTM4B gene polymorphism and breast cancer susceptibility in an Iranian population

Lysosome associated protein transmembrane 4beta (LAPTM4B) contribute to the risk of numerous cancers. The present study focused on the possible association between LAPTM4B polymorphism and the risk of breast cancer (BC) in an Iranian population in southeast Iran. This case control study includes 311 BC patients and 225 healthy women. Genomic DNA was extracted from the whole blood by salting out method and LAPTM4B genotype was investigated using polymerase chain reaction. Our findings showed that LAPTM4B genotype was not associated with the risk of BC in any inheritance model tested. The minor allele frequency in case and control group was 0.297 and 0.278, respectively. The minor allele (LAPTM4B*2) was not associated with BC risk in comparison with LAPTM4B*1 allele (odds ratio 1.10, 95 % confidence intervals 0.84-1.44, p = 0.495). Moreover, LAPTM4B polymorphism was not associated with clinical and pathological characteristics in the patient group. In conclusion, the findings of our study suggested that the polymorphism of LAPTM4B gene was not associated with susceptibility to BC and clinicopathological characteristics in an Iranian population.

Transcriptomic architecture of the adjacent airway field cancerization in non-small cell lung cancer

BACKGROUND

Earlier work identified specific tumor-promoting abnormalities that are shared between lung cancers and adjacent normal bronchial epithelia. We sought to characterize the yet unknown global molecular and adjacent airway field cancerization (FC) in early-stage non-small cell lung cancer (NSCLC).

METHODS

Whole-transcriptome expression profiling of resected early-stage (I-IIIA) NSCLC specimens (n = 20) with matched tumors, multiple cytologically controlled normal airways with varying distances from tumors, and uninvolved normal lung tissues (n = 194 samples) was performed using the Affymetrix Human Gene 1.0 ST platform. Mixed-effects models were used to identify differentially expressed genes among groups. Ordinal regression analysis was performed to characterize site-dependent airway expression profiles. All statistical tests were two-sided, except where noted.

RESULTS

We identified differentially expressed gene features (n = 1661) between NSCLCs and airways compared with normal lung tissues, a subset of which (n = 299), after gene set enrichment analysis, statistically significantly (P < .001) distinguished large airways in lung cancer patients from airways in cancer-free smokers. In addition, we identified genes (n = 422) statistically significantly and progressively differentially expressed in airways by distance from tumors that were found to be congruently modulated between NSCLCs and normal lung tissues. Furthermore, LAPTM4B, with statistically significantly increased expression (P < .05) in airways with shorter distance from tumors, was upregulated in human immortalized cells compared with normal bronchial epithelial cells (P < .001) and promoted anchorage-dependent and -independent lung cancer cell growth.

CONCLUSIONS

The adjacent airway FC comprises both site-independent profiles as well as gradient and localized airway expression patterns. Profiling of the airway FC may provide new insights into NSCLC oncogenesis and molecular tools for detection of the disease.

Correlation of LAPTM4B polymorphisms with gallbladder carcinoma susceptibility in Chinese patients

Gallbladder carcinoma (GBC) is a malignancy with an extremely poor prognosis. In order to improve the survival rate, identification of new susceptibility risk factors is of importance. Here, we report findings on the novel cancer-related gene lysosomal protein transmembrane 4 beta (LAPTM4B) that has two alleles designated LAPTM4B*1 and LAPTM4B*2. Allele *1 differs from allele *2 in that it contains one copy of a 19-bp sequence, whereas this sequence is duplicated in exon 1 of allele *2. This study aimed to investigate the relationship of LAPTM4B allelic variation and GBC susceptibility. LAPTM4B genotype was analyzed in 155 healthy individuals and 91 GBC patients by PCR, and the genotypic distribution of LAPTM4B was analyzed with the chi-squared test. The frequency of allele *2 was 37.9 and 24.8% in the GBC and the control groups, respectively, representing a significant difference between these two groups (P<0.001). LAPTM4B allele *2 may be a risk factor associated with genetic susceptibility to GBC.

cAMP responsive element binding protein-1 is a transcription factor of lysosomal-associated protein transmembrane-4 Beta in human breast cancer cells

Lysosomal-associated protein transmembrane-4 beta (LAPTM4B) is a potential proto-oncogene, whose overexpression is involved in cancer occurrence and progression. Its transcript is up-regulated in various types of solid tumors including breast cancer. However, its transcriptional regulation mechanism is still unclear. To investigate the mechanism of transcriptional regulation of LAPTM4B in human breast cancer cells, a series of luciferase reporter constructs and construct with mutated binding site for cAMP responsive element binding protein-1 (CREB1) were generated by PCR amplification and transiently transfected into breast cancer cells to determine the transcriptional activities of different promoter regions. The +10+292 promoter region was possessed the highest transcriptional activity. The ability of CREB1 to bind the LAPMT4B promoter was confirmed by electrophoretic mobility shift assay, super-shift and RNA interference experiments. Our study identified the core promoter region responsible for constitutive expression of LAPTM4B and clarified that CREB1 played an important role in LAPTM4B transcriptional regulation in human breast cancer cells.

Association of LAPTM4B gene polymorphism with nasopharyngeal carcinoma susceptibility in a Chinese population

Lysosome-associated protein transmembrane-4 beta (LAPTM4B) is a novel cancer-related gene. It has two alleles designated LAPTM4B 1 and LAPTM4B 2. Previous studies have revealed that LAPTM4B polymorphisms contribute to the risk of many cancers. The aim of this study was to investigate the association between different LAPTM4B alleles and the risk of nasopharyngeal carcinoma (NPC), one of the most common cancers in southern China. Using polymerase chain reaction (PCR) in a case-control study, we detected the LAPTM4B genotype in peripheral blood samples from 134 patients with NPC and 327 control subjects. The chi-square test was used to analyze differences of categorical variables and Hardy-Weinberg equilibrium. Odds ratios and 95 % CI were computed using an unconditional logistic regression model. The frequency of allele 2 was 26.87 % in the NPC group, which was not significantly different from that of the control group (27.98 %, P = 0.867). Using the LAPTM4B 1/1 genotype as a reference, we found that the 1/2, 2/2 and 1/2 + 2/2 genotype were also not associated with the risk of NPC. No association was observed between LAPTM4B gene polymorphisms and the risk of NPC adjusted by gender and age. The results of our study indicated that the polymorphism of LAPTM4B gene did not influence the susceptibility of NPC in the Chinese population. Large-scale studies are needed to confirm our findings.

CIP2A is highly expressed in hepatocellular carcinoma and predicts poor prognosis

BACKGROUND

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is highly expressed in hepatocellular carcinoma (HCC) and promotes cell proliferation, cell invasion, and aggressive tumor behavior. However, there have been few studies on the usefulness of CIP2A as an independent prognostic index of HCC. In the current study, the aim was to explore the association between CIP2A expression and prognosis in HCC.

METHODS

The expression of CIP2A and c-MYC was examined by immunohistochemistry in 136 HCC specimens. CIP2A mRNA expression in 27 HCC tissues was also analyzed using quantitative reverse-transcription polymerase chain reaction. The prognostic significance was analyzed by the Kaplan-Meier survival method and log-rank test. Cox regression was adopted for univariate and multivariate analysis of prognostic factors.

RESULTS

CIP2A protein was found to be highly expressed in human liver cancer samples (85/136, 62.5%) and correlated with poor survival (P<0.05). The liver cancer tissues examined exhibited much higher levels of CIP2A mRNA compared with their corresponding normal tissues (19/27, 70.3%). Furthermore, CIP2A mRNA levels were correlated with c-MYC mRNA levels. In addition, the highly expressed CIP2A was associated with recurrence (P=0.014) and invasion (P=0.017) of HCC. Patients with high CIP2A expression had both poorer overall survival (OS) and disease-free survival (DFS). On multivariate analysis, the CIP2A status was a significant prognostic factor for OS and DFS (P=0.017, P=0.026, respectively).

CONCLUSIONS

CIP2A overexpression may be useful as an independent prognostic biomarker for OS and DFS of HCC.

LAPTM4B allele *2 is associated with breast cancer susceptibility and prognosis

Background

Lysosome-associated protein transmembrane 4 beta (LAPTM4B) has two alleles named LAPTM4B*1 and LAPTM4B*2. Allele *1 contains only one copy of a 19-bp sequence at the 5′UTR in the first exon, whereas this sequence of allele*2 is duplicated and arrayed as a tandem repeat. Previous studies revealed that LAPTM4B polymorphisms contribute to the risk of certain types of cancers. This study aimed to investigate the polymorphism of LAPTM4B in breast cancer by analysis the correlation of LAPTM4B genotype with breast cancer susceptibility, clinicopathologic features and prognosis.

Methods

Genotyping of the LAPTM4B polymorphism was determined by PCR method. The expression levels of LAPTM4B in breast cancer tissues and breast cancer cell lines were determined by quantitative reverse-transcription PCR (qRT-PCR) analysis. The correlation of LAPTM4B genotype with clinicopathologic parameters and prognosis were assessed statistically.

Results

The results of qRT-PCR analysis indicated that LAPTM4B*2 was associated with the higher level of LAPTM4B expression compared with the LAPTM4B*1 in both breast cancer cell lines and breast cancer tissues. We found that LAPTM4B*2 was associated with an increased risk for breast cancer. LAPTM4B*2 was significantly associated with higher histopathologic grade, lymph node metastasis and poor prognosis.

Conclusion

LAPTM4B*2 is a risk factor associated with breast cancer susceptibility and poor prognosis. LAPTM4B*2 may be a potential predicative marker for the susceptibility, progression and metastasis of breast cancer.

LAPTM4B allele *2 is a marker of poor prognosis for gallbladder carcinoma

Background

Lysosomal protein transmembrane 4 beta (LAPTM4B) is a novel cancer-related gene which has two alleles designated LAPTM4B*1 and LAPTM4B*2. In this study we investigated the correlation of LAPTM4B genotype with prognosis and clinicopathologic features in patients who had undergone curative resection for gallbladder carcinoma (GBC).

Methodology/Principal Findings

PCR assay was performed to determine the LAPTM4B genotype in 85 patients. The correlation of LAPTM4B genotype with clinicopathologic parameters was assessed with the Chi-squared test. Differences in patient survival were determined by the Kaplan–Meier method. Multivariate analysis of prognostic factors was carried out with Cox regression analysis. Patients with LAPTM4B *2 had both significantly shorter overall survival (OS) and shorter disease-free survival (DFS) (both P<0.001). Multivariate analysis showed that LAPTM4B genotype is a prognostic factor for OS and DFS (both P<0.001).

Conclusions/Significance

LAPTM4B allele *2 is a risk factor associated with poor prognosis in patients with resected GBC, and LAPTM4B status may be therefore be useful preoperatively as an adjunct in evaluation of the operability of GBC.

Overexpression of LAPTM4B-35 is associated with poor prognosis in colorectal carcinoma

BACKGROUND

The purpose of this study was to determine whether lysosome-associated protein transmembrane-4 beta (LAPTM4B) overexpression is associated with the prognosis in patients with colorectal cancer.

METHODS

LAPTM4B expression was evaluated in colorectal cancer patients by Western blot analysis and immunohistochemistry. Univariate and multivariate analyses were performed to determine the association between LAPTM4B expression and prognosis.

RESULTS

Among the 136 patients with colorectal cancer, 51 patients had low LAPTM4B expression, and 85 patients had high LAPTM4B expression. The sensitivity and specificity of LAPTM4B overexpression were 62.5% and 100%, respectively. The 5-year overall survival (OS) rates for patients with high and low LAPTM4B expression were 37.38% and 98.04%, respectively (hazard ratio = 22.774; 95% confidence interval [CI], 5.287-98.091; P < .0001). The 5-year disease-free survival rate was 21.15% for patients in the high-expression group and 91.82% for patients in the low-expression group (hazard ratio = 11.674; 95% CI, 3.562-38.263; P < .0001).

CONCLUSIONS

LAPTM4B overexpression is an independent factor in colorectal cancer prognosis, and it may be an important potential biomarker.

LAPTM4B allele *2 is a marker of poor prognosis following hepatic tumor resection for hepatocellular carcinoma

Background

Lysosomal protein transmembrane 4 beta (LAPTM4B) is a gene related to hepatocellular carcinoma that has two alleles designated LAPTM4B*1 and LAPTM4B*2. This study aimed to investigate the correlation of LAPTM4B genotype with prognosis and clinicopathologic features in patients who have undergone resection for hepatocellular carcinoma (HCC).

Methodology/Principal Findings

The LAPTM4B genotype was analyzed by PCR in 68 patients who had undergone curative hepatic resection for hepatocellular carcinoma. The correlation of LAPTM4B genotype with clinicopathologic parameters was assessed with the Chi-squared test. Differences in patient survival were determined by the Kaplan–Meier method. Multivariate analysis of prognostic factors was carried out with Cox regression analysis. Patients with LAPTM4B *2 had both significantly shorter overall survival (OS) and shorter disease-free survival (DFS) (both P<0.001). Multivariate analysis showed that LAPTM4B genotype is an independent prognostic factor for OS and DFS (both P<0.001).

Conclusions/Significance

Allele *2 of LAPTM4B is a risk factor associated with poor prognosis in patients with resected HCC. LAPTM4B status may be useful preoperatively as an adjunct in evaluation of the operability of HCC.

Elevated lysosome-associated protein transmembrane-4β-35 is an independent prognostic marker in pancreatic carcinoma

OBJECTIVES

To investigate the relationship between lysosome-associated protein transmembrane-4β-35 (LAPTM4B-35) and the clinicopathological features and prognosis of pancreatic carcinoma.

METHODS

The level of LAPTM4B-35 protein was determined by semi quantitative immunohistochemistry in pancreatic carcinoma specimens. The relationship between LAPTM4B-35 level and prognosis was determined using univariate and multivariate analyses.

RESULTS

A total of 98 patient samples were included. The presence of LAPTM4B-35 protein was confirmed in 77/98 (78.6%) patients and was significantly associated with tumour stage, degree of differentiation and pathological staging of pancreatic carcinoma after primary surgery. Patients with high LAPTM4B-35 levels had a poorer overall survival compared with patients with lower levels. Multivariate analysis showed that LAPTM4B-35 was an independent prognostic factor for overall survival.

CONCLUSIONS

LAPTM4B-35 was found to be present at high levels in a large proportion of patients with pancreatic carcinoma, and was closely related to disease progression and poor prognosis. LAPTM4B-35 may represent a new molecular target for the clinical evaluation and treatment of pancreatic carcinoma.

Correlation of LAPTM4B polymorphisms with hepatocellular carcinoma in Chinese patients

Hepatocellular carcinoma (HCC) is the leading cause of cancer mortality in many countries. Evaluation of new susceptibility risk factors is therefore warranted in order to explore means to improve the survival rate. Here, we report on a novel HCC-related gene known as lysosomal protein transmembrane 4 beta (LAPTM4B) that has two alleles designated LAPTM4B*1 and LAPTM4B*2. Allele *1 differs from allele *2 in that it contains one copy of a 19-bp sequence, whereas this sequence is duplicated in allele *2 in exon 1 of LAPTM4B. In this study, we aimed to investigate the relationship between LAPTM4B allelic variation and HCC susceptibility. The LAPTM4B genotype was analyzed in the blood samples from 102 HCC patients and 135 healthy individuals by PCR. The genotypic distribution of LAPTM4B was analyzed using the chi-squared test. The frequencies of allele *2 were 38.24 and 24.07% in the HCC group and control group, respectively, representing a significant difference between these two groups (P<0.001). Thus, allele *2 of LAPTM4B appears to be associated with genetic susceptibility of HCC and may therefore be considered as a risk factor.

Over-expression of LAPTM4B is associated with poor prognosis and chemotherapy resistance in stages III and IV epithelial ovarian cancer

BACKGROUND

The purpose of this study was to determine whether LAPTM4B over-expression is associated with the prognosis and chemotherapy resistance in patients with stages III and IV epithelial ovarian carcinoma, i.e., patients with peritoneal metastasis or lymph node metastasis of epithelial ovarian carcinoma.

METHODS

LAPTM4B expression was evaluated in 10 normal ovarian and 113 stages III-IV ovarian carcinomas specimens by Western blotting analyses and immunohistochemistry. Univariate and multivariate analyses were performed to determine the association between LAPTM4B expression and prognosis and the relationship between LAPTM4B over-expression and chemotherapy resistance.

RESULTS

Western blotting analysis demonstrated that LAPTM4B was overexpressed in ovarian cancers, and immunohistochemistry results revealed that 80 patients were LAPTM4B over-expression. The five-year overall survival (OS) rates for patients with high LAPTM4B expression and low LAPTM4B expression were 27.36% and 90.7%, respectively (hazard ratio = 20.611, 95% CI: 5.916-71.808, P < 0.0001). The five-year progression-free survival (PFS) rate was 17.68% for patients in the high-expression group and 84.42% for patients in the low-expression group (hazard ratio = 17.852, 95% CI: 6.31-5.935, P < 0.0001); The presence of chemotherapy resistance was significantly associated with LAPTM4B expression (OR: 36.609, 95% CI: 4.737-282.941, P = 0.0006).

CONCLUSIONS

LAPTM4B over-expression is an independent factor in stages III-IV epithelial ovarian carcinoma prognosis and chemotherapy resistance, and it may be an important potential biomarker.