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

The role and regulatory mechanism of lysosome associated protein transmembrane 4β in tumors

The oncogene LAPTM4B (encoding lysosome-associated protein transmembrane-4β), first cloned in hepatocellular carcinoma cells, is located on chromosome 8q22.1 and encodes two isoforms, LAPTM4B-35 and LAPTM4B-24. LAPTM4B proteins have four transmembrane structural domains and are mainly distributed in lysosomal and endosomal membranes of cells. Studies have shown that LAPTM4B is overexpressed in a variety of cancers, in which the genetic polymorphism of LAPTM4B is associated with tumor susceptibility. LAPTM4B also regulates various cell signaling pathways, interacts with autophagy-related proteins and ceramides, and regulates the autophagy process and the release of exosomes, which in turn affect the survival and drug resistance of tumor cells. In conclusion, this paper summarizes recent research on LAPTM4B, aiming to explore the role and potential mechanisms of LAPTM4B in a variety of tumors.

The association between COX-2 gene rs5275 polymorphism and Nasopharyngeal carcinoma risk

The overexpression of cyclooxygenase-2 (COX-2) was correlated with the invasion and lymphatic metastasis and with the clinical stage of Nasopharyngeal carcinoma (NPC). The C allele of COX-2 gene rs5275 polymorphism disrupts miR-542-3p function to promote COX-2 overexpression. To examine the role of COX-2 gene rs5275 polymorphism in NPC, we determined COX-2 gene rs5275 polymorphism by using a custom-by-design 48-Plex single nucleotide polymorphism (SNP) Scan™ Kit. We found that C allele or CC genotype of rs5275 polymorphism in COX-2 gene was associated with an increased risk of NPC. In stratified analyses, COX-2 gene rs5275 polymorphism was associated with the risk of NPC among females, smokers, and drinkers. Based on these results, we concluded that COX-2 gene rs5275 variant contributes to NPC risk in a Chinese population. Larger studies with more diverse ethnic populations are needed to confirm these results.

Association between LAPTM4B gene polymorphism and susceptibility to and prognosis of diffuse large B-cell lymphoma

Lysosomal protein transmembrane 4β (LAPTM4B) is an oncogene that is overexpressed in a number of various types of human cancer. There are two known alleles of LAPTM4B: LAPTM4B*1 and LAPTM4B*2. The present study assessed the association between LAPTM4B polymorphisms and the susceptibility to diffuse large B-cell lymphoma (DLBCL) and its prognosis. LAPTM4B genotypes were determined using polymerase chain reaction analysis in 164 DLBCL and 350 healthy control cases. The association between LAPTM4B polymorphisms and the risk of DLBCL was analyzed using unconditional logistic regression. Differences in patient survival were calculated using Kaplan-Meier analysis. The present study indicated no significant differences (P>0.05) in the frequency of LAPTM4B*2 alleles between DLBCL cases (26.5%) and controls (24.1%). The risk of DLBCL was slightly increased in cases with the LAPTM4B*1/2 genotype [odds ratio (OR)=1.160; 95% confidence interval (CI)=0.781–1.724] or the LAPTM4B*2/2 genotype (OR=1.446; 95% CI=0.648–3.227) compared with those with the LAPTM4B*1/1 genotype. There was no significant association between the presence of the LAPTM4B*2 allele and overall survival (OS) and disease-free survival (DFS) in patients with DLBCL (P=0.399 and 0.520, respectively). However, there was a tendency for patients with LAPTM4B*2 and International Prognostic Index (IPI) score 3–5 to have longer OS and DFS (P=0.126 and 0.109, respectively). These findings suggest that genetic polymorphisms of LAPTM4B is not a risk factor for the development of DLBCL, but the LAPTM4B*2 allele may a better prognostic indicator in patients with IPI score 3–5 in DLBCL.

LAPTM4B*2 allele is associated with the development of papillary thyroid carcinoma in Chinese women

Lysosome-associated protein transmembrane 4-β (LAPTM4B) contains a polymorphic region that contributes to the increased risk of numerous types of tumor. However, no study has yet demonstrated an association between the expression of the LAPTM4B gene and tumor differentiation, and the reason that LAPTM4B polymorphisms affect the susceptibility of individuals to cancer remains to be elucidated. The present study assessed the possible association between LAPTM4B polymorphism and the risk of papillary thyroid carcinoma (PTC), and attempted to identify the underlying mechanism for variation in patient susceptibility with respect to transcription regulation in the polymorphism region. The case control study included 183 papillary thyroid carcinoma patients (132 females, 51 males) and 697 healthy controls (249 females, 448 males). Genomic DNA was extracted from the blood and the genotype of LAPTM4B was identified using polymerase chain reaction (PCR). The results of the PCR revealed that LAPTM4B allele *2 was associated with PTC risk in comparison with LAPTM4B allele *1 [odds ratio (OR), 1.968; 95% confidence interval (CI), 1.363-2.841, P<0.001] in females, while LAPTM4B*2 was not associated with PTC risk in males (OR, 0.996, 95% CI, 0.615-1.612, P=0.986). Notably, LAPTM4B polymorphism was not associated with clinical parameters in the female patient group. In addition, by performing a luciferase reporter assay in the PTC TPC1 and B-CPAP cell lines, the transcriptional activity of the +10/+311 plasmid, representing LAPTM4B*2 was reduced compared with that of the +10/+292 plasmid representing LAPTM4B*1. In conclusion, the results of the present study suggested that LAPTM4B*2 was a susceptibility factor for PTC in the female Chinese population and this may not be caused by the transcriptional regulation of LAPTM4B polymorphism region in TPC1 and B-CPAP cell lines.

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: 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.

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.

The relationship between LAPTM4B polymorphisms and cancer risk in Chinese Han population: a meta-analysis

LAPTM4B is a newly cloned gene that shows an active role in many solid tumors progression in substantial researches, mainly through the autophage function. Accumulated studies have been conducted to determine the association of LAPTM4B polymorphism with cancer risk. While the results are inconsistent, we conducted the meta-analysis to determine the strength of the relationship. Results showed that allele*2 carriers exhibited a significantly increased risk of cancer development with comparison to allele*1 homozygote (for *1/2, OR = 1.55, 95% CI 1.367-1.758; for *2/2, OR = 2.093, 95%CI 1.666-2.629; for *1/2 + *2/2, OR = 1.806, 95%CI 1.527-2.137). We also observed a significant association between *2/2 homozygote and cancer risk with comparison to allele*1 containing genotypes (OR = 1.714, 95%CI 1.408-2.088). Allele*2 is a risk factor for cancer risk (OR = 1.487, 95%CI 1.339-1.651). Stratified analysis by tumor type exhibits the significant association of this genetic variants with various cancers. In conclusion, LAPTM4B polymorphism is associated with cancer risk and allele*2 is a risk factor.

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.

LAPTM4B polymorphism increases susceptibility to multiple cancers in Chinese populations: a meta-analysis

Background

Lysosome-associated protein transmembrane-4 beta (LAPTM4B) is a novel cancer-related gene. While recent studies have reported that the LAPTM4B polymorphism increased the susceptibility of several cancers, the results remain inconclusive. Therefore, we performed a meta-analysis to systematically summarize the possible association.

Results

The meta-analysis was conducted based on 17 studies in Chinese populations, including 4160 cases and 4148 controls. The relevant studies were searched through electronic databases updated in November 2013. The strength of association between the LAPTM4B polymorphism and susceptibility to multiple cancers was assessed by odds ratio (OR) and 95% confidence interval (95% CI).

The meta-analysis results suggested that the LAPTM4B polymorphism was significantly associated with overall susceptibility to multiple cancers in all genetic models (*2 vs. *1, OR = 1.53, 95% CI = 1.37–1.70; *2/2 vs. *1/1, OR = 2.18, 95% CI = 1.72–2.75; *2/1 vs.*1/1, OR = 1.62, 95% CI = 1.41–1.86; *2/1 + *2/2 vs. *1/1, OR = 1.70, 95% CI = 1.47–1.97; *2/2 vs. *2/1 + *1/1, OR = 1.76, 95% CI = 1.50–2.05). Further subgroup analysis revealed a significant association between the LAPTM4B polymorphism and cancer susceptibility in the subgroups stratified by control source, cancer type, histopathologic differentiation, and TNM stage.

Conclusions

This meta-analysis indicated that the LAPTM4B *2 allele was associated with increasing risk of multiple cancers, tumor initiation and development.