Association of lnc-LAMC2-1:1 rs2147578 and CASC8 rs10505477 Polymorphisms with Risk of Childhood Acute Lymphoblastic Leukemia

Linear and Circular Long Non-Coding RNAs in Acute Lymphoblastic Leukemia: From Pathogenesis to Classification and Treatment

The coding regions account for only a small part of the human genome, and the remaining vast majority of the regions generate large amounts of non-coding RNAs. Although non-coding RNAs do not code for any protein, they are suggested to work as either tumor suppressers or oncogenes through modulating the expression of genes and functions of proteins at transcriptional, posttranscriptional and post-translational levels. Acute Lymphoblastic Leukemia (ALL) originates from malignant transformed B/T-precursor-stage lymphoid progenitors in the bone marrow (BM). The pathogenesis of ALL is closely associated with aberrant genetic alterations that block lymphoid differentiation and drive abnormal cell proliferation as well as survival. While treatment of pediatric ALL represents a major success story in chemotherapy-based elimination of a malignancy, adult ALL remains a devastating disease with relatively poor prognosis. Thus, novel aspects in the pathogenesis and progression of ALL, especially in the adult population, need to be further explored. Accumulating evidence indicated that genetic changes alone are rarely sufficient for development of ALL. Recent advances in cytogenic and sequencing technologies revealed epigenetic alterations including that of non-coding RNAs as cooperating events in ALL etiology and progression. While the role of micro RNAs in ALL has been extensively reviewed, less attention, relatively, has been paid to other non-coding RNAs. Herein, we review the involvement of linear and circular long non-coding RNAs in the etiology, maintenance, and progression of ALL, highlighting the contribution of these non-coding RNAs in ALL classification and diagnosis, risk stratification as well as treatment.

CASC8 lncRNA Promotes the Proliferation of Retinoblastoma Cells Through Downregulating miR34a Methylation

Background

CASC8 lncRNA has been proven to be oncogenic in a variety of cancers, but its role in other types of cancer remains unclear. This study was to investigate the role of CASC8 in retinoblastoma (Rb).

Methods

RT-qPCR was performed to determine the expression of CASC8 and miR34a in paired Rb and nontumor tissue. Overexpression of CASC8 and miR34a in Rb cells was achieved to evaluate the interaction between them. Methylation-specific PCR was used to analyze the effect of CASC8 overexpression on MIR34A gene methylation. CCK8 assays were used to analyze cell proliferation.

Results

The results showed that CASC8 expression was upregulated and miR34a expression downregulated in Rb tissue. Moreover, miR34a expression was negatively correlated with the of CASC8 expression in Rb tissue. Overexpression of CASC8 decreased expression of miR34a and increased methylation of MIR34A in Rb cells. In addition, overexpression of CASC8 reduced the inhibitory effects of miR34a on Rb-cell proliferation.

Conclusion

CASC8 may promote Rb cell proliferation by downregulating miR34a methylation.

Genetics of blood malignancies among Iranian population: an overview

BACKGROUND

Blood malignancies are among the leading causes of cancer related deaths in the world. Different environmental and genetic risk factors are involved in progression of blood malignancies. It has been shown that the lifestyle changes have affected the epidemiological patterns of these malignancies. Hematologic cancers are the 5th common cancer among Iranian population. It has been observed that there is a rising trend of blood malignancies incidences during the recent decades. Therefore, it is required to design novel diagnostic methods for the early detection of such malignancies in this population.

MAIN BODY

In present review we have summarized all of the significant genes which have been reported among Iranian patients with blood malignancies. The reported genes were categorized based on their cell and molecular functions to clarify the molecular biology and genetics of blood malignancies among Iranian patients.

CONCLUSION

It was observed that the epigenetic and immune response factors were the most frequent molecular processes associated with progression of blood malignancies among Iranian population. This review paves the way of introducing a population based panel of genetic markers for the early detection of blood malignancies in this population.

Long non-coding RNAs as the critical factors during tumor progressions among Iranian population: an overview

BACKGROUND

Cancer is associated with various genetic and environmental risk factors. Beside the mutations or aberrant expression of protein-coding genes, the genetic deregulation of non-coding RNAs has also an important role during tumor progression and metastasis. Long non-coding RNAs (lncRNAs) are a class of ncRNAs larger than 200 nucleotides that may function as tumor-suppressor or oncogene.

MAIN BODY

There is a raising trend of cancer incidence among Iranian population during the last decades. Therefore, it is required to prepare a general population specific panel of genetic markers for the early detection of cancer in this population. The tissue-specific expression characteristics and high stability in body fluids highlight the lncRNAs as efficient diagnostic and prognostic noninvasive biomarkers in cancer. In present review we summarized all of the lncRNAs which have been reported until now in different tumors among Iranian patients.

CONCLUSIONS

This review paves the way of introducing a population based noninvasive diagnostic panel of lncRNAs for the early detection of tumor cells among Iranian population.

Association between genetic polymorphisms of long noncoding RNA H19 and cancer risk: a meta-analysis

Long noncoding RNA (lncRNA) H19, a well-known oncogenic lncRNA, is overexpressed in various cancers. Several studies have investigated the association between polymorphisms in lncRNA H19 and the risk of various cancer types; however, the findings were inconsistent. In this study, we performed a meta-analysis to identify the precise association between H19 polymorphisms and cancer risk. Appropriate studies were retrieved from searching Web of Science, PubMed, Scopus, and Google scholar databases, updated 25 November 2018. The pooled odds ratios (ORs with 95% confidence intervals (CIs) were calculated to estimate the strength of the association between H19 polymorphisms and cancer risk. Our findings revealed that the H19-rs217727 C>T polymorphism is significantly associated with an increased risk of overall cancer in homozygous codominant (OR=1.28, 95% CI=1.04-1.57, P =0.020, TT vs CC), dominant (OR=1.20, 95% CI=1.04-1.37, P =0.010, CT+TT vs CC), recessive (OR=1.21, 95% CI=1.00-1.46, P =0.048, TT vs CT+CC), and allele (OR=1.16, 95% CI=1.05-1.28, P =0.003, T vs C) genetic models. No significant correlations were observed between H19: rs2839698 G>A, rs2107425 C>T, rs2735971 C>T, rs3024270 G>C, rs3741219 T>C, rs2839701 C>G, rs2735469 C>T, rs17658052 G>A, and rs3741216 T>A polymorphisms and overall cancer risk. Stratified analysis by cancer type proposed that the rs217727 variant is associated with increased risk of oral squamous cell carcinoma (OSCC) and lung cancer, whereas the rs2839698 variant is associated with increased risk of gastrointestinal cancer. Taken together, these findings support an association between H19 rs217727, and rs2839698 polymorphisms and cancer susceptibility. Larger and well-designed studies are necessary to further confirm these findings in detail.

Association of lncRNA CCAT2 and CASC8 Gene Polymorphisms with Hepatocellular Carcinoma

The worldwide incidence of hepatocellular carcinoma (HCC), the major histological type of primary liver cancer, is heterogeneous due to the variable prevalence of etiological factors, indicating a correlation of HCC risk with genetic variations among individuals. Among long non-coding RNAs (lncRNAs) located in the chromosome 8q24 loci and involved in the carcinogenesis are colon cancer associated transcript 2 (CCAT2) and cancer susceptibility candidate 8 (CASC8). In this study, the association of CCAT2 and CASC8 gene polymorphisms with the occurrence of HCC was explored between 397 HCC patients and 1195 controls. We found that carriers of rs6983267 GG in CCAT2 were more susceptible to HCC, with the odds ratio (OR) and adjusted odds ratio (AOR) being 1.532 (95% CI, 1.103–2.129; p = 0.011) and 1.627 (95% CI, 1.120–2.265; p = 0.033), respectively. Moreover, for patients stratified by age (under 65), gender (male only), or status of drinking (habitual drinkers), a protective effect of CASC8 rs3843549 on presenting high Child–Pugh scores, metastatic vascular invasion, or large-size tumors was observed in a dominant model. Collectively, our data reveal association of CCAT2 and CASC8 gene polymorphisms with the occurrence and progression of HCC.

The rs2147578 C > G polymorphism in the Inc-LAMC2-1:1 gene is associated with increased neuroblastoma risk in the Henan children

BACKGROUND

The rs2147578 C > G polymorphism in the long non-coding RNA gene Lnc-LAMC2-1:1 is associated with increased susceptibility to a few types of cancers. However, its role in neuroblastoma has not been evaluated yet.

METHODS

We investigated the association between the lnc-LAMC2-1:1 rs2147578 C > G polymorphism and neuroblastoma susceptibility in Chinese Han populations. A total of 393 neuroblastoma cases and 812 healthy individuals from the Henan and Guangdong provinces were enrolled and subjected to genotyping. Odds ratio (OR) and 95% confidence interval (CI) were used to determine the strength of the association of interest.

RESULTS

Combined analysis revealed that the lnc-LAMC2-1:1 rs2147578 C > G polymorphism was associated with increased neuroblastoma susceptibility (CG vs. CC: adjusted OR = 1.33, 95% CI = 1.01-1.75, P = 0.045; CG/GG vs. CC: adjusted OR = 1.34, 95% CI = 1.03-1.74, P = 0.028). In stratification analysis, children under 18 months with rs2147578 CG/GG genotypes had an increased neuroblastoma risk (adjusted OR = 1.70, 95% CI = 1.08-2.67, P = 0.022). Females with rs2147578 CG/GG genotypes also had increased neuroblastoma susceptibility (adjusted OR = 2.08, 95% CI = 1.37-3.18, P = 0.0007). In addition, children with lnc-LAMC2-1:1 rs2147578 CG/GG genotypes were prone to develop earlier stages of neuroblastoma (adjusted OR = 1.46, 95% CI = 1.01-2.12, P = 0.046).

CONCLUSIONS

The Lnc-LAMC2-1:1 rs2147578 C > G polymorphism may contribute to increased neuroblastoma susceptibility in children of Henan province.

Association between lncRNA CASC8 polymorphisms and the risk of cancer: a meta-analysis

Objective

To explore the relationship between single-nucleotide polymorphisms (SNPs) in one of the long noncoding RNA (lncRNA), cancer susceptibility candidate 8 (CASC8) gene and the risk of cancer.

Materials and methods

A meta-analysis was conducted to summarize the relationship between common SNPs (rs10505477 and rs7837328) in the lncRNA CASC8 gene and the risk of cancer. The relevant references were retrieved from several authoritative databases. Rigorous inclusion and exclusion criteria were adopted to ensure the credibility of the results. The fixed effects or random effects model was used to calculate the OR and 95% CI. We tested for publication bias.

Results

Fifteen articles containing 20 datasets (24,504 cases and 22,969 controls) were finally included in the meta-analysis. Compared to the individuals carrying the rs10505477 TT genotype, those with the TC or CC genotype had a decreased risk of cancer (TC vs TT: OR 0.876, 95% CI 0.832–0.923, P<0.001; CC vs TT: OR 0.748, 95% CI 0.703–0.795, P<0.001). Allele C of rs10505477 might be a protective factor for decreasing susceptibility to cancer (OR 0.866, 95% CI 0.840–0.893, P<0.001). As for rs7837328, the GA and AA genotypes were associated with increased risks of cancer as compared to the GG genotype (ORs 1.209 and 1.336; 95% CIs 1.127–1.298 and 1.202–1.484, respectively); its A allele could significantly increase the risk of cancer compared with the G allele (OR 1.169, 95% CI 1.114–1.227, P<0.001).

Conclusion

The rs10505477 and rs7837328 polymorphisms might be associated with risk of cancer.

Association of ARID5B Genetic Variants with Risk of Childhood B Cell Precursor Acute Lymphoblastic Leukaemia in Latvia

Background: Acute lymphoblastic leukaemia (ALL) is the most common malignancy in childhood. Despite numerous investigations very little is still known about its aetiology. However, in one genome wide association study conducted to identify the possible genetic risk factors, two allelic variations rs10821936 and rs10994982 in the 3rd intron of the ARID5B gene were identified as possible ALL risk alleles. Association between ARID5B gene variants and ALL risk was also been confirmed for different ethnic groups. Materials and Methods: Eight genetic variants in the gene ARID5B were genotyped - rs10994982, rs7908445, rs7923074, rs10821936, rs10821937, rs7896246, rs10821938 and rs7089424 in 77 ALL patients in remission and in 122 age and gender matched controls; parental samples were also genotyped in 50 cases. Results: Six out of the eight (rs7908445, rs7923074, rs10821936, rs10821937, rs7896246 and rs7089424) analysed allelic variations were identified in the case-control analysis as statistically significant risk alleles for ALL development. In the family study and using hybrid analysis, all allelic variations were significantly associated with ALL. During the study, risk haplotype was identified rs10994982/rs7908445/rs7923074/ rs10821936/ rs10821937/rs7896246/rs10821938/rs7089424 – ATACCAAG – with a frequency in cases of 0.17 and in the control group at 0.29 (chi square = 6.69, p value = 0.009). In the family association study the same haplotype showed statistical significance (chi squared = 10.3, p value = 0.001). Conclusions: Results of the study replicate and extend previously published findings for ARID5B localized allelic variants, but do not explain the mechanism of action related to the pathogenesis of ALL.

Long non-coding RNA PAX8-AS1 polymorphisms increase the risk of childhood acute lymphoblastic leukemia

The present case-control study was conducted on 110 children with acute lymphoblastic leukemia (ALL) and 120 healthy children to determine the impact of polymorphisms in paired-box gene 8 (PAX8) antisense RNA 1 (PAX8-AS1), namely rs4848320 C>T, rs6726151 T>G and rs1110839 G>T, on ALL risk. Genotyping was performed through the polymerase chain reaction-restriction fragment length polymorphism method. The findings indicated that the rs4848320 variant increased the risk of ALL in codominant [CT vs. CC: odds ratio (OR)=2.13, 95% confidence interval (CI)=1.16-3.90, P=0.014; and TT vs. CC: OR=2.21, 95% CI=1.03-4.74, P=0.041], dominant (CT+TT vs. CC: OR=2.15, 95% CI=1.22-3.81, P=0.009,) and allele (T vs. C: OR=1.55, 95% CI=1.07-2.25, P=0.024) inheritance models. The rs6726151 variant significantly increased the risk of ALL in codominant (GT vs. GG: OR=1.88, 95% CI=1.08-3.27, P=0.036) and overdominant (GT vs. GG+TT: OR=2.08, 95% CI=1.23-3.53, P=0.008) inheritance models. No significant relationship was identified between the rs1110839 G>T variant and disease risk/protection in childhood ALL. In conclusion, the findings of the present study indicated that rs4848320 and rs6726151 polymorphisms of PAX8-AS1 may be a risk factor for the development of childhood ALL. Further studies with larger sample sizes and different ethnicities are now required to confirm these findings.