Expression profiling revealed up-regulation of three lncRNAs in breast cancer samples

Long non-coding RNAs (lncRNAs) have been vastly investigated for their critical roles in the pathogenesis of breast cancer. Yet, the expression pattern and clinical significance of three lncRNAs namely CTBP1AS2, LINC-ROR and SPRY4-IT1 in breast cancer are not completely clarified. In the present investigation, we assessed expression of these lncRNAs in breast cancer tissues and paired non-cancerous specimens from the same patients using quantitative real time PCR. Notably, expression of CTBP1AS2, LINC-ROR and SPRY4-IT1 were upregulated in breast cancer tissues compared with non-cancerous tissues (ER = 17.62, P value<0.000; ER = 4.62, P value = 0.001 and ER = 3.47, P value = 0.005, respectively). Relative expression of LINC-ROR in tumoral tissues compared with non-tumoral tissues was associated with a history of hormone replacement therapy (P = 0.04). Expression levels of CTBP1AS2, LINC-ROR and SPRY4-IT1 were significantly correlated with each other in both tumoral and non-tumoral tissues. The strongest correlations were detected between CTBP1AS2/ LINC-ROR and CTBP1AS2/ SPRY4-IT1 pairs in non-tumoral tissues. CTBP1AS2 and SPRY4-IT1 had the best sensitivity (80%) and specificity (64%) values, respectively. Based on AUC values, the best diagnostic power belonged to CTBP1AS2. The current study potentiates CTBP1AS2, LINC-ROR and SPRY4-IT1 as putative contributors in the pathogenesis of breast cancer and suggests these lncRNAs as candidates for functional analysis in this kind of cancer.

Anti-angiogenic effects of testis-specific gene antigen 10 on primary endothelial cells

Growing evidence indicates the antitumor and antiangiogenesis activities of testis-specific gene antigen 10 (TSGA10). However, the underlying mechanisms and precise role of TSGA10 in angiogenesis are still elusive. In this study, we isolated human umbilical cord vein endothelial cells (HUVECs) and stably transfected with pcDNA3.1 carrying TSGA10 coding sequence. We demonstrated that TSGA10 over-expression significantly decreases HUVEC tubulogenesis and interconnected capillary network formation. HUVECs over-expressing TSGA10 exhibited a significant decrease in migration and proliferation rates. TSGA10 over-expression markedly decreased expression of angiogenesis-related genes, including VEGF-A, VEGFR-2, Ang-1, Ang-2, and Tie-2. Our ELISA results showed the decrease in VEGF-A mRNA expression level is associated with a significant decrease in its protein secretion. Additionally, over-expressing TSGA10 decreased expression levels of marker genes of cell migration (MMP-2, MMP-9, and SDF-1a) and proliferation (PCNA and Ki-67. Furthermore, ERK-1 and AKT phosphorylation significantly reduced in HUVECs over-expressing TSGA10. Our findings suggest a potent anti-angiogenesis activity of TSGA10 in HUVECs through down-regulation of ERK and AKT signalling pathways, and may provide therapeutic benefits for the management of different pathological angiogenesis.

Stimulatory effects of Lactobacillus casei derived extracellular vesicles on toll-like receptor 9 gene expression and cytokine profile in human intestinal epithelial cells

Background

A complex community of microorganisms in the gastrointestinal (GI) tract, known as the gut microbiota, exerts major effects on gene expression and cytokine profile. Extracellular vesicles (EVs) which are produced by bacteria could be sensed by Toll like receptors (TLRs). The interaction between gut microbiota and TLRs affects homeostasis and immune responses. In this study, we evaluated TLR9 gene expression and cytokines level in Caco-2 cell line treated with Lactobacillus casei as one of the gut microbiota and its EVs.

Methods

In the present study, L. casei derived EVs was extracted via ultracentrifugation. The quality control assessment included the evaluation of physicochemical characteristics of EVs. For the treatment of Caco-2 cell line, L. casei and its EVs (100 and 150 μg/mL) were used. In addition, qRT-PCR assay was carried out to evaluate the mRNA expression of TLR9 gene. ELISA assay was also performed to determine the levels of IFN_γ, TNF-α, GM-CSF, IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-12, IL-17A, and IL-10 cytokines.

Results

The results showed that L. casei slightly increased TLR9 gene expression in the Caco-2 cell line. It was also found that EVs at concentrations of 100 and 150 μg/mL could significantly decrease TLR9 gene expression. Furthermore, L. casei significantly increased IL-10 and IFN_γ levels. Based on the findings, the level of IL-17A, as a proinflammatory cytokine, decreased by L. casei. Both concentrations of EVs decreased the level of IFN_γ, while increasing the concentrations of IL-4 and IL-10. EVs from L. casei could modulate immune responses in the Caco-2 cell line. Both EVs and L. casei activated the expression and secretion of several cytokines.

Conclusions

L. casei and its EVs have pivotal role in the cross talk between gut microbiota and the host especially in the modulation of the immune system. This study shows for the first time the increasing level of anti-inflammatory cytokines by EVs released by L. casei. Based on the last studies on immunomodulatory effect of EVs on immune cells and our results in cell line level, we postulate that L. casei derived EVs could be possible candidates for the reduction of immune responses.

Investigation of promoter methylation of MCPH1 gene in circulating cell-free DNA of brain tumor patients

INTRODUCTION

Despite advanced diagnostic and therapeutic techniques, many brain tumors are still diagnosed at high grades and, therefore finding novel molecular markers may assist in early detection and reducing brain tumors-related mortality rate. Owing to the previous reports on the importance of MCPH1 gene in tumorigenesis, the present study was aimed to study the promoter methylation of MCPH1 gene in paired circulating cell-free DNA (cfDNA) and tumor tissues of brain tumor patients.

MATERIALS AND METHODS

Fourteen fresh paired serum and tumor tissue samples in addition to 18 isolated serum samples were collected from patients affected by different grades of brain tumor. Genomic DNA and cfDNA was isolated from tissue and serum samples using QIAamp DNA Mini Kit Norgen Bioteck Kit, respectively. Methylation DNA immunoprecipitation Real-time polymerization chain reaction (MeDIP-Real-time PCR) was performed on isolated DNA samples using EpiQuik MeDIP Ultra Kit and specific primer pairs. cfDNA quantity was determined through Real-time PCR analysis using specific primer pairs designed for GAPDH gene.

RESULTS

MCPH1 was methylated in 54% of cfDNA samples which was significantly associated with tumor grade, as well (P-value = 0.02). The methylation rate of MCPH1 was found as 78% in the tissue samples which was meaningfully associated with tumor grade (P-value = 0.03). Moreover, methylation of the MCPH1 gene was consistent in 57% of the same cfDNA and tissue samples. Methylation of MCPH1 gene in neither tumor tissues nor cfDNA was not correlated with age and sex of the patients.

DISCUSSION AND CONCLUSION

Due to the conformity of methylation of MCPH1 gene in cfDNA and tissue samples in more than half of the enrolled patients, especially in higher grades of tumors, it seems that MCPH1 promoter methylation could be a potential epimarker in not only detection of brain tumors but also in response to chemo- and radiotherapy which warranted further assessment.

Efficacy of co-immunization with the DNA and peptide vaccines containing SYCP1 and ACRBP epitopes in a murine triple-negative breast cancer model

Multiepitope cancer vaccines have gained lots of attention for prophylactic and therapeutic purposes in cancer patients. In our previous study, multiepitope DNA and peptide cancer vaccines consisted of the most immunodominant epitopes of ACRBP and SYCP1 antigens were designed by bioinformatic tools. In this study, the effect of prophylactic co-immunization with these DNA and peptide cancer vaccines in the 4T1 breast cancer animal model was assessed. Serum levels of the peptide-specific IgG total, IgG2a and IgG1 were measured by enzyme-linked immunosorbent assay (ELISA). Also, the efficacy of the immunized mice splenocytes' for producing interleukin-4 (IL-4) and interferon-γ (IFN-γ) was evaluated. The co-immunization caused a significant (P < .05) increase in the serum levels of IgG1 and IgG2a. The co-immunized mice splenocytes exhibited significantly enhanced IL-4 (6.6-fold) and IFN-γ (19-fold) production. Also, their lymphocytes exhibited higher proliferation rate (3-fold) and granzyme B production (6.5-fold) in comparison with the control. The prophylactic co-immunization significantly decreased the breast tumors' volume (78%) and increased the tumor-bearing mice survival time (37.5%) in comparison with the control. Taking together, prophylactic co-immunization with these multiepitope DNA and peptide cancer vaccines can activate the immune system against breast cancer. However, further experiments are needed to evaluate their efficacy from different angles.

Evaluation of the Epigenetic Demethylation of NRF2, a Master Transcription Factor for Antioxidant Enzymes, in Colorectal Cancer

Background

Epigenetic changes in CpG islands of the promoter regions of homeostasis-related genes, including nuclear factor erythroid 2-related factor 2 (NRF2), have been shown to hold a significant role in the development of colorectal cancer. Therefore, we aimed to examine the DNA demethylation pattern of the NRF2 promoter region in cancerous lesions from patients with colorectal cancer and the association of methylation status with clinicopathological features in the Iranian population.

Methods

In this cross-sectional study, 114 colorectal tissue samples were collected. These samples included: 34 tumour tissue samples, 60 precancerous polyps, and 20 normal tissue samples. The promoter methylation status of the NRF2 gene was examined using methylation-specific PCR. Additionally, the relationship between the methylation status and the clinicopathological features was investigated.

Results

The frequency of NRF2 demethylation in the tumour samples was significantly higher compared to the polyp tissues (p= 0.003) and normal tissue (p= 0.009), indicating that cancerous colorectal tissues exhibit increased demethylation of the NRF2 promoter. After examining the demethylation status of tissue samples, the clinicopathological features were compared to the demethylation results. No significant association was found between NRF2 promoter demethylation and the clinicopathological features of patient samples.

Conclusion

Our findings suggest that the epigenetic modifications leading to NRF2 demethylation found in colorectal tumour samples may contribute to cancer progression from precancerous polyps to cancerous lesions.

Influence of Follicular Fluid and Seminal Plasma on The Expression of Endometrial Receptivity Genes in Endometrial Cells

Objective

Endometrial receptivity plays a key role in pregnancy success in assisted reproduction cycles. Recent evidence suggests that seminal plasma (SP) and follicular fluid (FF) influence the uterine endometrium to improve implantation of the embryo and the establishment of pregnancy. In this study, we attempt to assess the influence of FF and SP on the expression levels of main endometrial receptivity genes (HOXA10, HOXA11, ITGAV, ITGB3 and LIF) in endometrial stromal cells.

Materials and Methods

In this experimental study, SP and FF were collected from 15 healthy fertile men and 15 healthy fertile women, respectively. Tissue specimens of the endometrium were obtained from 12 women undergoing hysterectomy for benign conditions. After endometrial stromal cell isolation and culture, dose- and time-dependent cytotoxic effects of pooled FF and SP on 3D-cultured endometrial cells were evaluated. A second independent set of 12 endometrium samples was treated under determined optimum conditions and evaluated for gene expression analysis using quantitative real-time polymerase chain reaction (qRT-PCR).

Results

The results of this study indicated that exposure of endometrial stromal cells to FF resulted in the elevated expression of HOXA10 (fold change=2.6, P=0.02), HOXA11 (fold change=3.3, P=0.002), LIF (fold change=4.6, P=0.0003), ITGB3 (fold change=3.5, P=0.012), and ITGAV (fold change=2.8, P=0.001) compared to untreated cells. In addition, we found that SP-treated endometrial cells showed increased mRNA levels of only the LIF gene (fold change=2.5, P=0.008) compared to untreated cells.

Conclusion

Human SP and FF may modulate the endometrial receptivity and improve the implantation rate in assisted reproduction cycles through the up-regulation of endometrial receptivity genes.

Expression analysis of vimentin and the related lncRNA network in breast cancer

Vimentin (VIM) is a mesenchymal marker which is expressed in some cancer types including breast cancer. A long non-coding RNA (lncRNA) has been identified to be transcribed from VIM gene locus and positively regulate expression of VIM. This lncRNA has been named as VIM-antisense 1 (VIM-AS1). Expression of VIM is also regulated by another lncRNA namely AGAP2-antisense RNA 1 (AGAP2-AS1). In the current study, we aimed at identification of the expression pattern of VIM, VIM-AS1, AGAP2 and AGAP2-AS1 in 78 breast cancer samples and their paired adjacent non-cancerous tissues (ANCTs) by means of real time PCR. All mentioned genes were significantly down-regulated in tumoral tissues compared with ANCTs (P values less than 0.000). Relative expression of VIM-AS1 in tumoral tissues versus ANCTs was associated with menopause age (P = .02) in a way that this gene was down-regulated in most of patients whose menopause age was between 40 and 50 years. Moreover, AGAP2-AS1 relative expression was associated with patients' body mass index (P = .03). There were trends toward association between VIM relative expression and tumor size (P = .07) and association between VIM-AS1 relative expression and obesity (P = .06). Expression of VIM was significantly higher in tumoral tissues of patients who had history of hormone replacement therapy compared with those without such history (P = .03). Moreover, expression levels of both VIM and AGAP2-AS1 were lower in patients whose menarche age was between 10 and 12 years old compared with those whose menarche age was between 13 and 15 years old (P values = .01 and 0.04, respectively). Transcript quantities of VIM, VIM-AS1, AGAP2 and AGAP2-AS1 were correlated with each other both in tumoral tissues and in ANCTs. Among four assessed genes, AGAP2 had the best diagnostic power for discrimination of tumoral tissues from ANCTs (AUC value = 0.87). Combination of four genes led to enhancement of AUC value to 0.94. The current study shows the importance of VIM and its associated lncRNAs in breast cancer and potentiates these genes as biomarkers for this malignancy. Moreover, these lncRNAs might be regarded as therapeutic targets in breast cancer.

Evaluation of lactic acid bacteria isolated from poultry feces as potential probiotic and its in vitro competitive activity against Salmonella typhimurium

The efficacy of probiotics as alternatives to antibiotics has been defined as one of the potential strategies to prevent Salmonella spp. infection in poultry. The purpose of this study was to isolate probiotic native Lactic acid bacteria (LAB) with high compatibility to intestinal tract and prevention of Salmonella typhimurium from broiler chicken feces. Thirty-seven samples of chicken feces were collected from seven broiler chicken farms in Northern Iran. The isolates identification was carried out with morphological and biochemical tests. Agar diffusion methods were used to evaluate the antimicrobial activities against Escherichia coli and S. typhimurium. The primary probiotic characteristics such as resistance to acid and bile and adhesion to Caco-2 cells were studied. Indeed, the ability of LAB isolates to inhibit adhesion of S. typhimurium to Caco-2 cells was evaluated by exclusion, competition and displacement assays. Among 42 isolates, S08, S01 and S06 isolates which showed appropriate probiotics characteristics were selected. Isolates S08 and S01 showed to be able to adhere strongly and also S06 was adhered moderately. In the exclusion assay, the isolates S08, S01 and S06 significantly hampered adhesion of S. typhimurium cell, in the competition assay, the isolates S08, S01 showed significant level of competition activity against S. typhimurium adherence to Caco-2 cells and isolate S08 showed the greatest displacement activity. The 16S rDNA sequence revealed that S08, S01, and S06 isolates were 99.00% similar to Lactobacillus salivarius, Lactobacillus johnsonii, and Pediococcus acidilactici, respectively. The result of this study suggested that LAB isolated from broiler chicken feces could be a remarkable reservoir for identification of probiotic to inhibit the pathogenic bacteria growth.

Heat shock factor 5 is essential for spermatogenesis in mice: Detected by a new monoclonal antibody

OBJECTIVES

Here, we examined the function of our produced monoclonal antibody (mAb10C3) to recognize one of the most important members of the HEAT shock factor family, Hsf5, in embryonic development and in spermatogenic cells of adult mouse testis.

MATERIALS AND METHODS

The targeting effects of mAb10C3 were investigated by immunohistochemistry analysis in the different phases of the embryo and in the adult testis tissue sections.

RESULTS

The results of immunohistochemistry staining on the mouse embryos by the supernatant of hybridoma clone that produced mAb10C3, in the early and late phases (E7.5 and E14.5) of embryonic development, indicated that mAb10C3 could only detect Hsf5 in E7.5 and it did not have any targeting activity in the late phase of development. Therefore, we showed that the hsf5 gene has expressed in early mouse embryonic development. On the other hand, mAb10C3 could detect Hsf5 in spermatogonia and spermatocytes of adult testis in comparison with a known anti-Hsf5 antibody (ab98939) and an anti-PCNA antibody as a marker of spermatogonia cells.

CONCLUSION

Taken together, these data indicated that generated anti-testis mAb10C3 was generated against anti-testis proteins, specifically to target Hsf5, and can be useful as a scientific tool to investigate the critical genes in the development and spermatogenesis.

Genotype-phenotype correlation and description of two novel mutations in Iranian patients with glycogen storage disease 1b (GSD1b)

Background

Glycogen storage disease (GSD) is a rare inborn error of the synthesis or degradation of glycogen metabolism. GSD1, the most common type of GSD, is categorized into GSD1a and GSD1b which caused by the deficiency of glucose-6-phosphatase (G6PC) and glucose-6-phosphate transporter (SLC37A4), respectively. The high rates of consanguineous marriages in Iran provide a desirable context to facilitate finding the homozygous pathogenic mutations. This study designates to evaluate the clinical and genetic characteristics of patients with GSD1b to assess the possible genotype-phenotype correlation.

Results

Autozygosity mapping was performed on nineteen GSD suspected families to suggest the causative loci. The mapping was done using two panels of short tandem repeat (STR) markers linked to the corresponding genes. The patients with autozygous haplotype block for the markers flanking the genes were selected for direct sequencing. Six patients showed autozygosity in the candidate markers for SLC37A4. Three causative variants were detected. The recurrent mutation of c.1042_1043delCT (p.Leu348Valfs*53) and a novel missense mutation of c.365G > A (p.G122E) in the homozygous state were identified in the SLC37A4. In silico analysis was performed to predict the pathogenicity of the variants. A novel whole SLC37A4 gene deletion using long-range PCR and sequencing was confirmed as well. Severe and moderate neutropenia was observed in patients with frameshift and missense variants, respectively. The sibling with the whole gene deletion has shown both severe neutropenia and leukopenia.

Conclusions

The results showed that the hematological findings may have an appropriate correlation with the genotype findings. However, for a definite genotype-phenotype correlation, specifically for the clinical and biochemical phenotype, further studies with larger sample sizes are needed.

Optimized protocol for soluble prokaryotic expression, purification and refolding of the human inhibin α subunit, a cysteine rich peptide chain

BACKGROUND

Inhibin A, a member of TGF-β superfamily, consists of α and β subunits. These subunits contain several cysteine residues in amino acid sequence that forms inter- and intra-subunits disulfide bonds. Due to the reducing environment of the bacterial cytoplasm, disulfide bonds formation in E.coli cytoplasm is not possible. Therefore, this can cause misfolding, aggregation and inclusion bodies formation during protein expression. As a result, the expression of inhibin subunits in E.coli produces inclusion bodiesOBJECTIVE: We aimed at identification of an optimized protocol for expression and recovery of inhibin α-subunit from inclusion bodies.

METHODS

Two vectors, four different E.coli strains, and six solubilization conditions for were used for the optimization of inhibin α-subunit production. Then, the solubilized proteins were purified through Ni-NTA affinity chromatography, characterized by SDS-PAGE and Western blotting (WB) using anti-his tag antibody, and refolded by dilution.

RESULTS

The results showed that inhibin α-subunits were successfully expressed in both vectors and the pET22b+inhibin α-subunit in ShuffleTM T7 strain had the highest expression; however, most of the expression was in an insoluble form. Among solubilization buffers examined, a buffer containing 2M urea with pH 12 was the best buffer to dissolve the insoluble protein. The high purity of protein was confirmed by SDS-PAGE and WB. Non-reducing SDS-PAGE demonstrating inhibin α-subunit refolded well.

CONCLUSION

The current protocol is an efficient method for protocol for expression and recovery of inhibin α-subunit from inclusion bodies.

Rapamycin Reduces Cervical Cancer Cells Viability in Hypoxic Condition: Investigation of the Role of Autophagy and Apoptosis

BACKGROUND

Rapamycin has been known as an anti-cancer agent that affects different malignancies such as glioblastoma and prostate cancer. However, there are few studies concerning rapamycin effects on the cervical cancer cells. In this study, it was aimed to investigate the possible effect of rapamycin on a cervical cancer cell line and explored the possible mechanism(s) and pathway(s) for this agent.

MATERIALS AND METHODS

To do so, HeLa cells as cervical cancer cell line were used and treated with different concentrations of rapamycin under both normoxic and hypoxic conditions. Then, cell viability assays, Western blot, quantitative real-time polymerase chain reaction (QR-PCR), acridine orange and acridine orange/propidium iodide staining were performed to evaluate rapamycin effect on the mentioned cell line.

RESULTS

The results showed that autophagy and apoptosis-related genes increased significantly in rapamycin-treated HeLa cells compared to controls. Moreover, cervical cancer cell death by rapamycin-induced autophagy in hypoxia was greater than normoxia compared with controls. In this study, it was showed that autophagy induction by rapamycin can mediate programmed cell death of cervical cancer cells, especially in hypoxic condition.

CONCLUSION

These findings provide a new evidence that rapamycin may inhibit hypoxic HeLa cell proliferation through the trigger of programmed cell death, facilitating the development of novel anti-cancer therapy.

Engineered Jurkat Cells for Targeting Prostate-Specific Membrane Antigen on Prostate Cancer Cells by Nanobody-Based Chimeric Antigen Receptor

Background:

Recently, modification of T cells with CAR has been an attractive approach for adoptive immunotherapy of cancers. Typically, CARs contain a scFv. Most often, scfvs are derived from a monoclonal antibody of murine origin and may be a trigger for host immune system that leads to the T-cell clearance. Nanobody is a specific antigen-binding fragment derived from camelid that has great homology to human VH and low immunogenic potential. Therefore, in this study, nanobody was employed instead of scFv in CAR construct.

Methods:

In this study, a CAR was constructed based on a nanobody against PSMA (NBPII-CAR). At first, Jurkat cells were electroporated with NBPII-CAR, and then flow cytometry was performed for NBPII-CAR expression. For functional analysis, CAR T cells were co-cultured with prostate cancer cells and analyzed for IL-2 secretion, CD25 expression, and cell proliferation.

Results:

Flow cytometry results confirmed the expression of NBPII-CAR on the transfected Jurkat cells. Our data showed the specificity of engineered Jurkat cells against prostate cancer cells by not only increasing the IL-2 cytokine (about 370 pg/ml) but also expressing the T-cell activation marker CD25 (about 30%). In addition, proliferation of engineered Jurkat cells increased nearly 60% when co-cultured with LNCaP (PSMA⁺), as compared with DU145 (PSMA^-).

Conclusion:

Here, we describe the ability of nanobody-based CAR to recognize PSMA that leads to the activation of Jurkat cells. This construct might be used as a promising candidate for clinical applications in prostate cancer therapy.

Identification of common vaginal Lactobacilli immunoreactive proteins by immunoproteomic techniques

Lactobacilli are considered as the most important microorganisms in regulating immune system and maintaining vaginal health. The uses and benefits of Lactobacilli as probiotics, particularly the regulation of immune system, are dependent on the strain used and a comprehensive understanding of their effects on the host. Several factors have been identified in Lactobacilli that influence the immune response, such as exopolysaccharides and proteins. The current study was designed to investigate the serum immunoreactivity of healthy women against common vaginal Lactobacilli immunoreactive proteins. Three common vaginal Lactobacillus strains (L. crispatus L1, L. gasseri L9, and L. fermentum L2) were compared for immune response. The ELISA results showed that the levels of total immunoglobulin (Ig-total) antibody for L. crispatus L1, L. fermentum L2, and L. gasseri L9 were 47%, 45% and 29%, respectively. Regarding the lower prevalence of L. fermentum L2 in comparison with the other two strains, the approximately equal levels of Ig-total compared to L. crispatus L1 and more than L. gasseri L9 indicate that L. fermentum L2 has the greater antigenicity ability. Accordingly, the immunoreactive proteins of L. fermentum L2 were identified using MALDI-TOF-MS detected by SDS-PAGE and Western blotting. These proteins included 30s ribosomal protein S4 and 50s ribosomal protein L5. Antigenic epitopes on the 3D structure of these proteins was also predicted using bioinformatics analysis. The presence of antibody in serum of healthy pre-menopausal women indicates that Lactobacilli (normal flora) proteins can stimulate host immune response. Purification and further studies of the proteins may allow their potential use as an adjuvant to improve the efficacy of vaccines.

Clinical Correlation of miR-200c/141 Cluster DNA Methylation and miR-141 Expression with the Clinicopathological Features of Colorectal Primary Lesions/Tumors

BACKGROUND

Abnormal DNA methylation leading to altered transcription of certain genes occurs frequently in colorectal cancer (CRC). As with protein-coding genes, microRNAs (miRNAs) may be targeted for methylation in CRC; however, the methylation state of miRNA genes in CRC, especially in primary lesions, has not yet been completely elucidated. To understand the impact of DNA methylation on the miR-200c/141 cluster promoter, we investigated the methylation and expression of miR-141 in precancerous lesions and colorectal cancer.

METHODS

In this cross-sectional study, 208 colorectal tissue samples, including 34 tumor tissue samples, 60 precancerous lesions with matched normal adjacent tissues, and 20 normal tissue samples, were collected. Promoter methylation of the miR-200c/141 cluster was studied using methylation-specific PCR. MiR-141 expression was examined using quantitative real-time PCR.

RESULTS

Our findings showed that the miR-200c/141 cluster promoter region was most frequently hypermethylated in colorectal tumors and adenomatous polyps, but unmethylated in hyperplastic polyp tissues (P < 0.001). DNA methylation of the miR-200c/141 cluster and the tumor stage were significantly correlated (P = 0.002); however, miR-141 expression difference between the tumor and polyp samples was not significant (p = 0.6).

CONCLUSION

The DNA methylation status of the miR-200c/141 cluster could serve as a progression marker from benign polyps to colorectal cancer.

Physico-chemical and cytotoxic analysis of a novel large molecular weight bacteriocin produced by Lactobacillus casei TA0021

BACKGROUND AND OBJECTIVES

Antimicrobial peptides produced by lactic acid bacteria have gained enormous attention owing to their health benefits. This study aimed to isolate, purify and characterize the antibacterial protein produced by autochthonous Lactobacillus casei TA0021 strain.

MATERIALS AND METHODS

The antagonistic activity of L. casei TA0021 against a number of pathogenic bacteria was tested by agar well diffusion assay. The antimicrobial agent in the neutralized supernatant fluids was subjected to the action of proteolytic enzymes, catalase, lipase and lysozyme, and their tolerance to variable pH and temperature was estimated. The proteinaceous antagonistic compound was precipitated by 60% w/v ammonium sulphate, desalted and subjected to cation exchange and gel filtration chromatography. Approximate molecular weight of Lactocin was determined by SDS-PAGE and non-denaturing gel electrophoresis. Hemoglobin release assay and cytotoxicity effect of Lactocin TA0021 was determined. The results were statistically analyzed.

RESULTS

The antagonistic agent active against Salmonella Typhimurium and Shigella flexneri appeared resistant to catalase and lipase treatments, while sensitive to the tested proteolytic enzymes. Lactocin TA0021 resisted acidic pH values of 3.0, while alkaline pH values of >9 completely destroyed the activity. The antibacterial peptide was approximately 68 KDa and heat labile as lost its activity at 100°C after 5 minutes. The bacteriocin was non-toxic to MRC-5 cell lines and non-hemolytic. Purification method lead to increase in antibacterial activity while, subsequent decrease in recovery and yield was observed with increasing purification fold.

CONCLUSION

The purified antimicrobial protein from L. casei TA0021 might be used for application in medicinal and food products.

Production, purification, and in vivo evaluation of a novel multiepitope peptide vaccine consisted of immunodominant epitopes of SYCP1 and ACRBP antigens as a prophylactic melanoma vaccine

Melanoma cells are significantly resistance to the current treatments. Therefore, the best option for high-risk populations is prevention. Recently, many preventive cancer vaccines have been developed. In our previous study, several bioinformatic tools were employed for selection of the most immunodominant epitopes of acrosin binding protein (ACRBP) and synaptonemal complex protein 1 (SYCP1) antigens to design multiepitope DNA and peptide cancer vaccines. In the current study, the final construct of the multiepitope DNA vaccine was placed into a pcDNA3.1 vector and then, subcloned into a pET-28a (+) expression vector for transfecting BL21 E. coli strain. The recombinant multiepitope peptide vaccine, weighing 6.35 kDa, was purified by Fast protein liquid chromatography technique (FPLC) and detected by western blotting. Subsequently, C57BL/6 mice were immunized by a mixture of the peptide vaccine and incomplete Freund's adjuvant (IFA) (four vaccinations with one-week intervals). Two weeks after the last vaccination, the serum levels of the peptide-specific IgG total, IgG2a, and IgG1 were measured by enzyme-linked immunosorbent assays (ELISA). Also, the immunized mice splenocytes efficacy for producing interleukin-4 (IL-4) and interferon-γ (IFN-γ) after stimulation with the peptide vaccine was evaluated. At last, the prophylactic effect of the peptide vaccine immunization was evaluated in B16-F10 murine melanoma model. The peptide vaccine immunization caused a significant increase in the serum levels of IgG1, IgG2a, and IgG2a. Also, the immunized mice splenocytes exhibited significantly higher ability to produce IL-4 (10-fold) and IFN-γ (16-fold) after stimulation with the peptide vaccine, in comparison with the PBS and IFA groups. The peptide immunized mice exhibited 50.2% and 43% decrease in the mean tumors' volume in comparison with PBS and IFA groups. Also, the mean survival time for the peptide immunized mice was 33 ± 1.3 days which was 5 and 6 days more than the PBS and IFA groups, respectively. The obtained results exhibit high efficacy of the designed multiepitope peptide vaccine for the immune system activation and anti-tumor prophylactic effects in the murine melanoma model.

Development, optimization, and validation of an in-house Dot-ELISA rapid test based on SAG1 and GRA7 proteins for serological detection of Toxoplasma gondii infections

Background

The aim of the present study was to develop a simple, portable, and rapid assay for serodiagnosis of toxoplasmosis based on recombinant Toxoplasma gondii (T. gondii) SAG1 (rSAG1) and GRA7 (rGRA7) proteins.

Methods

The rSAG1 and rGRA7 proteins were expressed in Escherichia coli (E. coli) and purified in a single step by immobilized metal ion affinity chromatography. The immunoreactivity of the recombinant antigens was tested in an in-house IgG and IgM Dot enzyme-linked immunosorbent assay (Dot-ELISA) for potential use in serodiagnosis of T. gondii infection.

Results

Results from the comparison of in-house rSAG1-Dot-ELISA with ELISA for the detection of anti-Toxoplasma IgG and IgM include sensitivity of 83.7% and 81.2%, specificity of 90.2% and 89.3%, positive predictive values of 85.9% and 68.4%, and negative predictive values of 88.6% and 94.3%, respectively. Sensitivity of 66.2%, specificity of 81.2%, positive predictive values of 71.6%, and negative predictive values of 77.1% were concluded from in-house IgG rGRA7-Dot-ELISA. The sensitivity and specificity of IgM rGRA7-Dot-ELISA included 87.5% and 83.9%, respectively. Sensitivity and specificity of in-house Dot-ELISA for a combination of rSAG1 and rGRA7 included 87.5% and 91.1% for IgG and IgM, respectively. Sensitivity and specificity of a combination of rSAG1 and rGRA7 for the detection of IgM in suspected sera to acute toxoplasmosis were higher than those for the detection of IgG in sera with chronic infections (90.6% and 92% instead of 86.2% and 91.6%, respectively).

Conclusion

The highlighted parameters of combined recombinant proteins were more significant than those of single recombinant proteins in in-house Dot-ELISA. These data suggest that the in-house Dot-ELISA based on rSAG1 and rGRA7 combination is a promising diagnostic tool with a similar sensitivity to the native antigens of T. gondii, which can be used for the serodiagnosis of toxoplasmosis in fields as well as less equipped laboratories.

The Impact of Long-term Exposure to Low Levels of Inorganic Arsenic on the Hypomethylation of SEPT9 Promoter in Epithelial-Mesenchymal Transformed Colorectal Cancer Cell Lines

Inorganic arsenicals are worldwide environmental contaminants that affect molecular characteristics in biological systems and lead to genomic and epigenomic instability as well as epithelial mesenchymal transition (EMT). In this study, we aimed to investigate whether low levels of sodium arsenite (iAsIII) can influence EMT and genomic instability through microsatellite analysis. We have also determined epigenomic instability by investigating the methylation status of SEPT9 tumor marker in colorectal cancer (CRC) cell lines, Caco2 and HCT116, which were treated with iAsIII to assess IC50s. Short-term and long-term exposure to low concentrations (1 µM and 0.1 µM) of iAsIII in two separate experiments was implemented to analyze EMT, microsatellite status and the methylation pattern of SEPT9 promoter. As expected, after 20 days of exposure to iAsIII, the expression of CDH1 was significantly decreased while the expression of CDH2, FIB1 and VIM was increased in Caco2 and HCT116, a finding that confirmed EMT induction. However, there was no detectable alteration in the size of microsatellites. As for the methylation pattern, SEPT9 promoter was hypomethylated as a result of long-term exposure to 0.1 µM iAsIII in Caco2. Long-term exposure of HCT116 to both concentrations could induce hypomethylation of SEPT9 promoter. Our findings indicate no linkage between EMT induction and microsatellite status in iAsIII-treated CRC cell lines. For the first time, the current study has shown that the induction of EMT by iAsIII is linked with SEPT9 promoter hypomethylation in Caco2 and HCT116 in a concentration- and time-dependent pattern.