Preclinical tumor mouse models for studying esophageal cancer

Preclinical models are extensively employed in cancer research because they can be manipulated in terms of their environment, genome, molecular biology, organ systems, and physical activity to mimic human behavior and conditions. The progress made in in vivo cancer research has resulted in significant advancements, enabling the creation of spontaneous, metastatic, and humanized mouse models. Most recently, the remarkable and extensive developments in genetic engineering, particularly the utilization of CRISPR/Cas9, transposable elements, epigenome modifications, and liquid biopsies, have further facilitated the design and development of numerous mouse models for studying cancer. In this review, we have elucidated the production and usage of current mouse models, such as xenografts, chemical-induced models, and genetically engineered mouse models (GEMMs), for studying esophageal cancer. Additionally, we have briefly discussed various gene-editing tools that could potentially be employed in the future to create mouse models specifically for esophageal cancer research.

The therapeutic potential value of Cancer-testis antigens in immunotherapy of gastric cancer

Gastric cancer (GC) is the fourth most common cause of mortality and the fifth for incidence, globally. Diagnosis, early prognosis, and therapy remains challenging for this condition, and new tumor-associated antigens are required for its detection and immunotherapy. Cancer-testis antigens (CTAs) are a subfamily of tumor-associated antigens (TAAs) that have been identified as potential biomarkers and targets for cancer immunotherapy. The CTAs-restricted expression pattern in tumor cells and their potential immunogenicity identify them as attractive target candidates in CTA-based diagnosis or prognosis or immunotherapy. To date, numerous studies have reported the dysregulation of CTAs in GC. Several clinical trials have been done to assess CTA-based immunotherapeutic potential in the treatment of GC patients. NY-ESO-1, MAGE, and KK-LC-1 have been used in GC clinical trials. We review recent studies that have investigated the potential of the CTAs in GC regarding the expression, function, aggressive phenotype, prognosis, and immunological responses as well as their possible clinical significance as immunotherapeutic targets with a focus on challenges and future interventions.

A new gene panel as a marker for ESCC poor prognosis; INPP5A, TWIST1, MMP2, and EGFR

PURPOSE

Esophageal squamous cell carcinoma (ESCC) is categorized among ten common aggressive malignancies, with a higher incidence and mortality rates in the developing than in developed countries. The inositol polyphosphate 5-phosphatase (INPP5A), as an intracellular-calcium mobilizer and modifier enzyme, facilitates cell responses to various stimuli. Epithelial-mesenchymal transition (EMT), a transformation procedure, has a vital role in cancer progression and metastasis when epithelial cells lose their traits in favor of obtaining mesenchymal features. In this study, we analyzed the correlation between the expression of INPP5A and the involved genes in EMT pathway through the progression and development of the ESCCs.

MATERIALS AND METHODS

The gene expression analyses of INPP5A, TWIST1, MMP-2, and EGFR were performed using relative comparative real-time PCR in 58 ESCCs patients compared to corresponding margin-normal esophageal tissues.

RESULTS

A significant inverse correlation between INPP5A and EGFR/MMP-2 mRNA expression was observed in tumor samples. Underexpression of INPP5A was significantly correlated with overexpression of TWIST1, MMP-2, and EGFR in different invasiveness and aggressiveness pathological features of the ESCCs (P ​< ​0.05).

CONCLUSIONS

The results propose a tumor suppressor role for INPP5A and oncogenic function for concomitant expression of the other genes in ESCC invasion and metastasis. The current study is the first report elucidating the correlation between the downregulation of INPP5A and upregulation of TWIST1, MMP-2, and EGFR in ESCC and introduces this panel of the genes as a marker for poor prognosis of the disease.

Novel mutation in AIRE gene with autoimmune polyendocrine syndrome type 1

PURPOSE

Autoimmune polyendocrine type 1 (APS-1) is a complex inherited autosomal recessive disorder. Classically, it appears within the first decade of life followed by adrenocortical insufficiency, mucocutaneous candidiasis, Addison's disease, and hypoparathyroidism. The clinical phenotype of APS-1 varies depending upon mutations in the autoimmune regulator gene (AIRE) on chromosome 21q22.3.

METHODS

In this study, we performed Sanger sequencing ofAIRE in Iranian patients to identify different variants and probable new mutations corresponding to a clinical diagnosis of APS-1.

RESULTS

After analyzing 14AIRE exons, we detected a novel insertion mutation in exon 2 in a patient who presented with severe APS-1, Lys50AsnfsX168. Furthermore, the known mutations in AIRE, including Arg139X, Arg257X, and Leu323SerfsX51, were detected in enrolled patients.

DISCUSSION

According to our results, sequencing analysis ofAIRE provides a useful screening method to diagnose patients with incomplete or unusual clinical presentations of APS-1.

Whole-exome sequencing of familial esophageal squamous cell carcinoma identified rare pathogenic variants in new predisposition genes

PURPOSE

Esophageal squamous cell carcinoma (ESCC) is one of the most important causes of mortality in the developing world. Although hereditary forms arise from germ-line mutations in TP53, Rb, and the mismatch repair genes, many familial cases present with an unknown inherited cause. The new theory of rare, high-penetrance mutations in less known genes is a likely explanation for the underlying predisposition in some of these familial cases.

METHODS

Exome sequencing was performed in 9 patients with esophageal squamous cancer from 9 families with strong disease aggregation without mutations in known hereditary esophageal cancer genes. Data analysis was limited to only really rare variants (0-0.01%), producing a putative loss of function and located in genes with a role compatible with carcinogenesis.

RESULTS

Twenty-two final candidate variants were selected and validated by Sanger sequencing. Correct family segregation and somatic studies were used to categorize the most interesting variants in CDK11A, ARID1A, JMJD6, MAML3, CDKN2AIP, and PHLDA1.

CONCLUSION

Together, we identified new potential esophageal squamous cancer predisposition variants in genes which may have a role in cancer and are involved in chromatin remodeling and cell-cycle pathway, which could increase the risk of ESCC.

TWIST1, MMP-21, and HLAG-1 co-overexpression is associated with ESCC aggressiveness

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive types of cancer, requiring reliable biomarkers for prognosis and therapeutic responsiveness. TWIST1, as an important factor responsible for metastasis of several cancers, is involved in tumor invasion and metastasis through indirectly regulation of MMP-21 expression. On the other hand, NF-ĸβ which is a regulator of HLAG-1 has direct interaction with TWIST1 protein. In this retrospective study we investigated the clinical significance of TWIST1, MMP-21, and HLAG-1 expression in ESCC, and the possible correlation between these genes and progression of the disease. The gene expression analyses of TWIST1, MMP-21, and HLA-G1 were performed by relative comparative real-time polymerase chain reaction in 58 ESCCs compared with corresponding margin-normal esophageal tissues. Significant overexpression of HLAG-1, TWIST1, and MMP-21 messenger RNA was observed in 22.4%, 41.4%, and 60.3% of tumor samples, respectively. Concomitant overexpression of TWIST1/MMP-21 and TWIST1/HLAG-1 were significantly correlated to each other in various clinicopathological features, including depth of tumor invasion, stage of tumor progression, lymphatic invasion, and grade of tumor cell differentiation ( P < 0.05). The current study is the first report of coexpression of TWIST1, MMP-21, and HLAG-1 in ESCC. Such findings suggest an oncogenic role for concomitant expression of these genes in ESCC invasion and metastasis.

Novel DNA variation of GPR54 gene in familial central precocious puberty

Background

Puberty can be considered the end point of a maturation process which is defined by the dynamic interactions of genes and environmental factors during prenatal and postnatal development. Kisspeptin/G protein-coupled receptor-54, is as an essential gatekeeper and regulator of GnRH neurons, and a key factor in initiation of puberty. Loss and gain of functional mutations in the GPR54 gene are associated with hypogonadotropic hypogonadism and precocious puberty, respectively. This study was designed to evaluate variations of GPR54 in familial precocious puberty.

Methods

Genomic DNA was extracted from peripheral whole blood of 25 subjects with familial precocious puberty. Coding exons 1–5 of the GPR54 gene were amplified by polymerase chain reaction (PCR) and the PCR products were purified and sequenced. DNA sequences were compared to the human GenBank GPR54 sequence using Sequencher sequence alignment software.

Results

We detected three different Single Nucleotide Polymorphisms (SNPs) in GPR54: rs10407968 (24A > T) in 13 subjects (52%); rs3050132 (1091 T > A) in 16 subjects (64%), and a novel polymorphism (492C > G) in one subject (4%), while three subjects (12%) had no SNPs. No mutations were found in the GPR54 gene.

Conclusions

Regarding the presence of SNPs in 88% of the subjects in this study, it is likely a relationship exists between the SNPs of the GPR54 gene and familial precocious puberty. Further research is needed to investigate this possibility, and potential functional effects of these polymorphisms.

Novel mutations and their genotype-phenotype correlations in patients with Noonan syndrome, using next-generation sequencing

PURPOSE

Noonan Syndrome (NS) is an autosomal dominant disorder with many variable and heterogeneous conditions. The genetic basis for 20-30% of cases is still unknown. This study evaluates Iranian Noonan patients both clinically and genetically for the first time.

MATERIALS/METHODS

Mutational analysis of PTPN11 gene was performed in 15 Iranian patients, using PCR and Sanger sequencing at phase one. Then, as phase two, Next Generation Sequencing (NGS) in the form of targeted resequencing was utilized for analysis of exons from other related genes. Homology modelling for the novel founded mutations was performed as well. The genotype, phenotype correlation was done according to the molecular findings and clinical features.

RESULTS

Previously reported mutation (p.N308D) in some patients and a novel mutation (p.D155N) in one of the patients were identified in phase one. After applying NGS methods, known and new variants were found in four patients in other genes, including: CBL (p. V904I), KRAS (p. L53W), SOS1 (p. I1302V), and SOS1 (p. R552G). Structural studies of two deduced novel mutations in related genes revealed deficiencies in the mutated proteins. Following genotype, phenotype correlation, a new pattern of the presence of intellectual disability in two patients was registered.

CONCLUSIONS

NS shows strong variable expressivity along the high genetic heterogeneity especially in distinct populations and ethnic groups. Also possibly unknown other causative genes may be exist. Obviously, more comprehensive and new technologies like NGS methods are the best choice for detection of molecular defects in patients for genotype, phenotype correlation and disease management.

Identification of four novel mutations of the WFS1 gene in Iranian Wolfram syndrome pedigrees

AIMS

Wolfram syndrome is a rare neurodegenerative disorder with an autosomal recessive pattern of inheritance characterized by various clinical manifestations. The related gene, WFS1, encodes a transmembrane glycoprotein, named wolframin. Genetic analyses demonstrated that mutations in this gene are associated with WS type 1. Our aim in this study was to sequence WFS1 coding region in Iranian Wolfram syndrome pedigrees.

METHODS

Genomic DNA was extracted from peripheral blood of 12 WS patients and their healthy parents. Exons 2-8 and the exon-intron junctions of WFS1 were sequenced. DNA sequences were compared to the reference using Sequencher software.

RESULTS

Molecular analysis of WFS1 revealed six different mutations. Four novel and two previously reported mutations were identified. One novel mutation, c.1379_1381del, is predicted to produce an aberrant protein. A second novel mutation, c.1384G > T, encodes a truncated protein. Novel mutation, c.1097-1107dup (11 bp), causes a frameshift which results in a premature stop codon. We screened for the novel missense mutation, c.1010C > T, in 100 control alleles. This mutation was not found in any of the healthy controls.

CONCLUSION

Our study increased the spectrum of WFS1 mutations and supported the role of WFS1 in susceptibility to WS. We hope that these findings open new horizons to future molecular investigations which may help to prevent and treat this devastating disease.