CaSilico: A versatile CRISPR package for in silico CRISPR RNA designing for Cas12, Cas13, and Cas14.

The efficiency of the CRISPR-Cas system is highly dependent on well-designed CRISPR RNA (crRNA). To facilitate the use of various types of CRISPR-Cas systems, there is a need for the development of computational tools to design crRNAs which cover different CRISPR-Cas systems with off-target analysis capability. Numerous crRNA design tools have been developed, but nearly all of them are dedicated to design crRNA for genome editing. Hence, we developed a tool matching the needs of both beginners and experts, named CaSilico, which was inspired by the limitations of the current crRNA design tools for designing crRNAs for Cas12, Cas13, and Cas14 CRISPR-Cas systems. This tool considers a comprehensive list of the principal rules that are not yet well described to design crRNA for these types. Using a list of important features such as mismatch tolerance rules, self-complementarity, GC content, frequency of cleaving base around the target site, target accessibility, and PFS (protospacer flanking site) or PAM (protospacer adjacent motif) requirement, CaSilico searches all potential crRNAs in a user-input sequence. Considering these features help users to rank all crRNAs for a sequence and make an informed decision about whether a crRNA is suited for an experiment or not. Our tool is sufficiently flexible to tune some key parameters governing the design of crRNA and identification of off-targets, which can lead to an increase in the chances of successful CRISPR-Cas experiments. CaSilico outperforms previous crRNA design tools in the following aspects: 1) supporting any reference genome/gene/transcriptome for which an FASTA file is available; 2) designing crRNAs that simultaneously target multiple sequences through conserved region detection among a set of sequences; 3) considering new CRISPR-Cas subtypes; and 4) reporting a list of different features for each candidate crRNA, which can help the user to select the best one. Given these capabilities, CaSilico addresses end-user concerns arising from the use of sophisticated bioinformatics algorithms and has a wide range of potential research applications in different areas, especially in the design of crRNA for pathogen diagnosis. CaSilico was successfully applied to design crRNAs for different genes in the SARS-CoV-2 genome, as some of the crRNAs have been experimentally tested in the previous studies.

Study on Early Onset Melanoma and Germ-Line Mutation in CDKN2A among Patients in Imam Khomeini Hospital Complex.

OBJECTIVE: Malignant melanoma is a highly lethal melanocytic neoplasia with different predisposing factors. The genetic background in familial cases is an important issue in finding at risk family members. CDKN2A is one of these predisposing genes which have been estimated to be involved in germ line mutation in approximately 5-10% of familial melanoma cases. MATERIALS AND METHODS: An inclusion criteria for familial melanoma was prepared according to the literature, and the age of onset was considered as a single criteria for selection. A total number of 322 melanoma cases were investigated regarding the criteria, among which 20 patients were chosen (<40 years). DNA was extracted from Formalin Fixed Paraffin Embed of normal tissues and DNA sequencing was performed for all coding sequences of CDKN2A (p16). RESULTS: One of the cases showed a pathogenic mutation in codon 108, exon 2(322G >C; Asp108His). Further analysis of his offspring indicated no mutation in the next generation. CONCLUSION: As far as the authors of the present study are concerned, this was the first report on this germ-line mutation with mentioned amino acid alteration in the melanoma. Screening the CDKN2A gene for possible mutation could prevent the incidence of familial cases in at risk members.
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Plasma Levels of MicroRNA-146a-5p, MicroRNA-24-3p, and MicroRNA-125a-5p as Potential Diagnostic Biomarkers for Rheumatoid Arthris.

Rheumatoid arthritis (RA) is an autoimmune disease that is characterized by inflammation of the articular tissue. This study aims to evaluate the expression of microRNA (miR)-146a-5p, miR-24-3p, and miR-125a-5p in the plasma of RA patients and compare them with those of healthy controls to obtain a specific expression profile for earlier diagnosis and assistance in treating patients. This study was performed on 50 RA patients and 50 healthy controls. Five microliters of blood were taken from each patient/control. Plasma RNA was extracted using the Trisol solution. cDNAs were synthesized; using moloney murine leukemia virus (MMLV) and deoxynucleoside triphosphate (dNTP). Real-time PCR was performed using SYBR green kit. The mean expression of miR-146a-5p, miR-24-3p, and miR-125a-5p in the RA group were 8.1±1.9, 6.5±1.2, and 6.8±2.2 and in the healthy group were 4.8±1.6, 3.6±2.2, and 3.4±1.7, respectively. Significant differences were also observed in the mean expression of these three miRNAs in four subgroups of RA patients with different disease activity based on disease activity score 28 (DAS28) (p<0.05). ROC curve analysis showed that miR-146a-5p (AUC=0.8, sensitivity= 96%, specificity=86%), miR-24-3p (AUC=0.7, Sensitivity=95%, Specificity=75%) and miR-125a-5p (AUC=0.71, sensitivity=93%, specificity=84%) could be used as suitable biomarkers for RA diagnosis. Increased expressions of miR-146a-5p, miR-24-3p, and miR-125a-5p in RA patients indicate that the miRNAs are involved in disease incidence and progression, and the measurement of their expression can play an essential role in the diagnosis and treatment of the disease.

Differential Expression Pattern of Epithelial Mesenchymal Transition Gens: AXL, GAS6, Claudin-1, and Cofilin-1, in Different Stages of Epithelial Ovarian Cancer.

BACKGROUND: Epithelial ovarian cancer (EOC), is the fatal form of gynecological cancer. Almost 70% of ovarian cancer patients are detected at an advanced stage (III-IV) with metastases. Epithelial-mesenchymal transition (EMT) is a critical process associated with metastasis. This study investigated the expression levels of AXL, GAS6, Claudin-1, and Cofilin-1, as genes involved in EMT in relation to clinicopathologic features in ovarian cancer patients. METHODS: In this descriptive study, 78 ovarian epithelial cancer patients were enrolled. Samples were provided by the Iran National Tumor Bank, founded by the Cancer Institute of Tehran University of Medical Sciences in 2017. The expression levels of AXL, GAS6, Claudin-1, and Cofilin-1 genes were investigated in a fresh, frozen tumor sample and normal adjacent tissue by real-time PCR (RT-PCR). RESULTS: Findings showed a significant relationship between the overexpression of AXL and TNM staging (P=0.03). The expression level of GAS6 decreased in more advanced stages (P=0.01). There is a negative relationship between Cofilin-1 expression level and TNM staging (P=0.002). Claudin-1 expression level was higher in low stages compared with that in high stages (P=0.01). There was no relationship between gene expression levels of target genes with size and grade of the tumor. CONCLUSION: Given the importance of these genes in EMT, alteration in their expression pattern can contribute to the progression of the disease and distant metastasis of cancer cells. Additionally, knowing the alteration pattern of these genes expression can help to better understanding and prediction of the prognosis of EOC.

Fibroblast growth factor-10 and epithelial-mesenchymal transition in colorectal cancer.

As an inducer of epithelial-mesenchymal transition (EMT), fibroblast growth factor-10 (FGF-10) has a role in cell proliferation and differentiation in the embryo in addition to invasion and metastasis during carcinogenesis. In this study, we aimed to investigate the FGF-10 gene expression in tumor tissues based on the pathological feature of tumor related to EMT and metastasis. 62 tumors were obtained from 62 colorectal cancer patients during surgery. The pathological characteristics of the patients were carefully collected and classified by Iran National Tumor Bank. To quantify FGF-10 gene expression, RNA extraction, reverse transcription-PCR and real-time PCR were respectively performed. In addition, three colorectal cancer cell lines including LS174T, SW-948 and SW-480 were collected and cultured for further molecular analysis. Consequently, FGF-10 gene expression showed increased expression level in LS174T and SW-948 while it displayed decreased level in SW-480. Considering the tumor samples, we found an upregulation of FGF-10 gene expression in 52.1 % of all tumors in stage III and only in 9.09 % of all tumors in stage I. Also, there were an upregulation of FGF-10 gene expression in 50 % of all positive lymph invasion patients. Besides, FGF-10 gene upregulation was observed in 50 % of all tumors with a size larger than 5 cm (P value < 0.05) and 69 % of all tumors located in the colon (P value < 0.05). To our knowledge, this is the first time that FGF-10 expression is reported based on pathological features of colorectal cancer.

DNA hypermethylation of GDF5 in developmental dysplasia of the hip (DDH).

INTRODUCTION & OBJECTIVE: Developmental Dysplasia of the Hip (DDH) is one of the most common congenital skeletal anomalies. Body of evidence suggests that genetic variations in GDF5 are associated with susceptibility to DDH. DDH is a multifactorial disease and its etiology has not been entirely determined. Epigenetic changes such as DNA methylation could be linked to DDH. In this scheme, we hypothesized that changes in GDF5 DNA methylation could predispose a susceptible individual to DDH. METHODS: This study consisted of 45 DDH patients and 45 controls with healthy femoral neck cartilage, who underwent hemi-, or total arthroplasty for the femoral neck fracture. A cartilage sample of 1 cm in diameter and 1 mm in the thickness was obtained for DNA extraction. DNA was extracted and DNA methylation of GDF5 was evaluated by metabisulfite method. RESULTS: Methylation analysis showed that the promoter of GDF5 in cartilage samples from DDH patients was hypermethylated in comparison to healthy controls (p = .001). CONCLUSION: Our study showed that the methylation status of the GDF5 in patients with DDH is dysregulated. This dysregulation indicates that adjustment in the methylation might modify the expression of this gene. Since this gene plays an essential role in cartilage and bone development, thus reducing its expression can contribute to the pathogenesis of DDH. Further studies are needed to elucidate the role of GDF5 in this disease.

Cancer-Testis Antigens as New Candidate Diagnostic Biomarkers for Transitional Cell Carcinoma of Bladder.

To evaluate the diagnostic potential of 23 candidate genes, belonging to a category of tumor-specific antigens known as cancer-testis antigens (CTAs), in transitional cell carcinoma (TCC) patients. The expression of 16 known candidate CTAs and seven testis restricted/selective genes, predominantly expressed in the testis, was evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR). Urinary exfoliated cells (UECs) and cancerous tissues of 73 TCC patients were used as cases, while 25 tumor-free adjacent bladder tissue specimens along with bladder tissue specimens and UECs of five non-TCC individuals were analyzed as controls. Among the known CTAs only MAGEA3, MAGEB4, TSGA10, PIWIL2, OIP5, and ODF4 were expressed specifically in TCC tissues and UEC samples. ACTL7A, AURKC, and CGB2 were testis-restricted/selective genes that indicated specific expression in cases in comparison to controls. MAGEA3, MAGEB4, and ODF4 mRNA was detectable in more than 50% of both TCC tissues, and UEC samples. Slight differences were detected in the mRNA expression pattern of candidate genes between the UEC samples and tumor tissues. Different panels formed by combinations of these genes can show up to 95.9% and 94.5% of positivity in TCC tissues and UEC samples, respectively, suggesting their diagnostic and surveillance potential. Meanwhile the RT-PCR assay of at least MAGEA3, MAGEB4, and ODF4 may be particularly useful for diagnostic and surveillance of TCC in the form of a multi-biomarker panel.

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.

The Association of miR-let 7b and miR-548 with PTEN in Prostate Cancer.

PURPOSE: This study aims to investigate the expression level of mir-let7b-3p and mir-548, which are involved in PTEN expression in tissue samples of prostate cancer patients versus benign prostate hyperplasia (BPH) and normal adjacent tissue. MATERIALS AND METHODS: Prostate cancer tissues were obtained from patients after receiving informed consent. Total RNA extraction and cDNA synthesis were performed for determining gene expression. RESULTS: Ten patients were determined to have high Gleason scores (> 7), 36 and seven samples had intermediate Gleason scores (7?) and BPH, respectively, and 40 samples were derived from normal adjacent tissue. Downreg-ulation of mir-let7b and upregulation of mir-548 expression significantly correlated with high-risk Gleason scores. CONCLUSION: The present study showed that miR-let7b and/or mir-548 can be considered as potential targets in prostate cancer therapy.

Expression profile of miRNAs in urine samples of bladder cancer patients.

AIM: miRNAs have been suggested as biomarkers for bladder cancer. We aimed to find a diagnostic panel of miRNAs based on differential expression of miRNAs in urine specimens of patient with bladder cancer compared with control group. METHODS: miR-141, miR-10b, miR-34b and miR-103 were selected to assess their expression in urine samples of 66 bladder cancer patients and 53 matched controls using quantitative real time PCR. RESULTS: miR-10b and miR-34b were upregulated in cases compared with controls. The combination of four miRNAs showed a sensitivity of 75% and specificity of 63.5% with a diagnostic power of 72%. CONCLUSION: Certain miRNAs can be used as biomarkers for early diagnosis of bladder cancer.

ODF4, MAGEA3, and MAGEB4: Potential Biomarkers in Patients with Transitional Cell Carcinoma

Background: This study aimed to evaluate the diagnostic value of outer dense fiber 4 (ODF4), melanoma-associated antigen A3 (MAGEA3), and MAGEAB4 mRNAs in transitional cell carcinoma (TCC), using a small amount of cell reverse transcriptase-polymerase chain reaction (RT-PCR) on urinary exfoliated cells. Methods: We recruited a total of 105 suspected TCC patients and 54 sex- and age-matched non-TCC controls. The candidates' genetic expression patterns were investigated with RT-PCR, while reverse transcription quantitative PCR was applied to quantify and compare each mRNA level between cases and control groups. Results: The sensitivity of ODF4, MAGEA3, and MAGEAB4 RT-PCR was 54.8%, 63%, and 53.4%, whereas the specificity was 73.7%, 86%, and 94.7%, respectively. Combining ODF4, MAGEA3, and MAGEAB4 RT-PCR offered a relatively higher sensitivity (83.6%). Conclusion: RT-PCR with ODF4, MAGEA3, and MAGEAB4 on urinary exfoliated cells could provide clinicians with a promising method to improve TCC diagnosis, especially in the case of gross hematuria and catheterization. The method used here is non-invasive, simple and convenient, and unlike cytology, it does not rely directly on expert professional opinions. These features can be of particular importance to the management of TCC patients in whom regular and lifelong surveillance is required.

A Patient With Desmoid Tumors and Familial FAP Having Frame Shift Mutation of the APC Gene.

Desmoids tumors, characterized by monoclonal proliferation of myofibroblasts, could occur in 5-10% of patients with familial adenomatous polyposis (FAP) as an extra-colonic manifestation of the disease. FAP can develop when there is a germ-line mutation in the adenomatous polyposis coli gene. Although mild or attenuated FAP may follow mutations in 5΄ extreme of the gene, it is more likely that 3΄ extreme mutations haveamore severe manifestation of thedisease. A 28-year-old woman was admitted to the Cancer Institute of Iran with an abdominal painful mass. She had strong family history of FAP and underwent prophylactic total colectomy. Pre-operative CT scans revealed a large mass. Microscopic observation showed diffuse fibroblast cell infiltration of the adjacent tissue structures. Peripheral blood DNA extraction followed by adenomatous polyposis coli gene exon by exon sequencing was performed to investigate the mutation in adenomatous polyposis coli gene. Analysis of DNA sequencing demonstrated a mutation of 4 bpdeletions at codon 1309-1310 of the exon 16 of adenomatous polyposis coli gene sequence which was repeated in 3 members of the family. Some of them had desmoid tumor without classical FAP history. Even when there is no familial history of adenomatous polyposis, the adenomatous polyposis coli gene mutation should be investigated in cases of familial desmoids tumors for a suitable prevention. The 3΄ extreme of the adenomatous polyposis coli gene is still the best likely location in such families.

Melanoma in Iran: a Retrospective 10-Year Study.

BACKGROUND: Melanoma, the most life-threatening type of skin cancer, is a malignant tumor initiating in melanocytes that rapidly metastasizes and causes death. MATERIALS AND METHODS: In this retrospective study, samples were selected from patients' information files in our Cancer Institute in Tehran with a designed checklist. A total of 322 files were found from 2003 until 2012. Then the raw data were transferred to Statistical Package for Social Sciences (SPSS) software version 16 and additional analysis was performed by Students t-test. The important variables were considered according to the available information from history of pathology including age, gender, occupation, stage and location of tumor. RESULTS: Our data showed that incidence of melanoma has been different in the studied 10-year period according to age. Also, incidence of melanoma was higher in men than women. It was more common in lower limbs. More commonly housewives among women and farmers among men were affected by melanoma. CONCLUSIONS: Taken together the descriptive data clarified general aspects of this disease for further screening and interventions.

The Effect of Lactobacillus crispatus and Lactobacillus rhamnosusCulture Supernatants on Expression of Autophagy Genes and HPV E6 and E7 Oncogenes in The HeLa Cell Line.

OBJECTIVE: The aim of this study was to clarify the mechanism by which lactobacilli exert their cytotoxic effects on cervical cancer cells. In addition, we aimed to evalu- ate the effect of lactobacilli on the expression of human papilloma virus (HPV) onco- genes. MATERIALS AND METHODS: In this experimental study, using quantitative real-time polymer- ase chain reaction (PCR), we analyzed the expression of CASP3 and three autophagy genes [ATG14, BECN1 and alpha 2 catalytic subunit of AMPK (PRKAA2)] along with HPV18 E6 and E7 genes in HeLa cells before and after treatment with Lactobacillus crispatus and Lactobacillus rhamnosus culture supernatants. RESULTS: The expression of CASP3 and autophagy genes in HeLa cells was de- creased after treatment with lactobacilli culture supernatants. However, this de- crease was not significant for PRKAA2 when compared with controls. In addition, expression of HPV E6 was significantly decreased after treatment with lactobacilli culture supernatants. CONCLUSION: Lactobacilli culture supernatants can decrease expression of ATG14 and BECN1 as well as the HPV E6 oncogene. It has been demonstrated that the main changes occurring during cervical carcinogenesis in cell machinery can be reversed by suppression of HPV oncogenes. Therefore, downregulation of HPV E6 by lacto- bacilli may have therapeutic potential for cervical cancer. As the role of autophagy in cancer is complicated, further work is required to clarify the link between downregula- tion of autophagy genes and antiproliferative effects exerted by lactobacilli.

Effects of exercise training together with tamoxifen in reducing mammary tumor burden in mice: Possible underlying pathway of miR-21.

Exercise training has an anti-tumor effect and can reduce tumor growth; however, the exact underlying mechanisms of its protective effects are still obscure. MicroRNA (miR)-21 is a predictor in cancer survival, and has a potential use as an indicator of therapeutic outcome in breast malignancies. Forty-eight female BALB/c mice were equally divided into six groups to investigate the effects of interval exercise training with tamoxifen on miR-21 expression and its possible assumed mechanisms in an estrogen receptor-positive breast cancer model. ELISA, immunohistochemistry, western blot, qRT-PCR assays were performed at the end of the study. Tumor size was significantly declined in exercise training and tamoxifen groups compared to tumor group (P<0.05). Expression of miR-21 was significantly down-regulated in trained and tamoxifen treated mice in comparison with tumor group (P<0.05). Exercise training was as effective as tamoxifen treatment in decreasing serum estradiol and ER-α expression (P<0.05). Exercise training and tamoxifen reduced tumor IL-6 levels, NF-kB and STAT3 expressions, and up-regulated TPM1 and PDCD4 expressions (P<0.05). Both exercise and tamoxifen had synergistic effects in reducing miR-21 and Bcl-2, and up-regulating PDCD4 expression. Results showed that interval exercise training may reduce mammary tumor burden in mice through possible underlying pathway of miR-21.

The multidrug resistance pumps are inhibited by silibinin and apoptosis induced in K562 and KCL22 leukemia cell lines.

Silibinin have been introduced for several years as a potent antioxidant in the field of nutraceuticals. Based on wide persuasive effects of this drug, we have decided to investigate the effects of silibinin on chronic myelogenous leukemia (CML) in vitro models, K562 and KCL22 cell lines. Lactate dehydrogenase (LDH) release, microculture tetrazolium test (MTT assay) and real-time PCR were employed to evaluate the effects of silibinin on cell cytotoxicity, cell proliferation and expression of various multidrug resistance genes in these cell lines, respectively. Our results have shown that presence of silibinin has inhibitory effects on cell proliferation of K562 and KCL22 cell lines. Also, our data indicated that silibinin, in a dose-dependent manner with applying no cytotoxic effects, inhibited cell proliferation and reduced mRNA expression levels of some transporter genes e.g. MDR1, MRP3, MRP2, MRP1, MRP5, MRP4, ABCG2, ABCB11, MRP6 and MRP7. The multifarious in vitro inhibitory effects of silibinin are in agreement with growing body of evidence that silibinin would be an efficient anticancer agent in order to be used in multi-target therapy to prevail the therapeutic hold backs against CML.

Overexpression of ubiquitin and amino acid permease genes in association with antimony resistance in Leishmania tropica field isolates.

The mainstay therapy against leishmaniasis is still pentavalent antimonial drugs; however, the rate of antimony resistance is increasing in endemic regions such as Iran. Understanding the molecular basis of resistance to antimonials could be helpful to improve treatment strategies. This study aimed to recognize genes involved in antimony resistance of Leishmania tropica field isolates. Sensitive and resistant L. tropica parasites were isolated from anthroponotic cutaneous leishmaniasis patients and drug susceptibility of parasites to meglumine antimoniate (Glucantime®) was confirmed using in vitro assay. Then, complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) and real-time reverse transcriptase-PCR (RT-PCR) approaches were utilized on mRNAs from resistant and sensitive L. tropica isolates. We identified 2 known genes, ubiquitin implicated in protein degradation and amino acid permease (AAP3) involved in arginine uptake. Also, we identified 1 gene encoding hypothetical protein. Real-time RT-PCR revealed a significant upregulation of ubiquitin (2.54-fold), and AAP3 (2.86-fold) (P<0.05) in a resistant isolate compared to a sensitive one. Our results suggest that overexpression of ubiquitin and AAP3 could potentially implicated in natural antimony resistance.

Identification of antimony resistance markers in Leishmania tropica field isolates through a cDNA-AFLP approach.

Pentavalent antimonial compounds have been the first line therapy for leishmaniasis; unfortunately the rate of treatment failure of anthroponotic cutaneous leishmaniasis (ACL) is increasing due to emerging of drug resistance. Elucidation of the molecular mechanisms operating in antimony resistance is critical for development of new strategies for treatment. Here, we used a cDNA-AFLP approach to identify gene(s) which are differentially expressed in resistant and sensitive Leishmania tropica field isolates. We identified five genes, aquaglyceroporin (AQP1) acts in drug uptake, ATP-binding cassette (ABC) transporter (MRPA) involved in sequestration of drug, phosphoglycerate kinase (PGK) implicated in glycolysis metabolism, mitogen activated protein kinase (MAPK) and protein tyrosine phosphatase (PTP) responsible for phosphorylation pathway. The results were confirmed using real time RT-PCR which revealed an upregulation of MRPA, PTP and PGK genes and downregulation of AQP1 and MAPK genes in resistant isolate. To our knowledge, this is the first report of identification of PTP and PGK genes potentially implicated in resistance to antimonials. Our findings support the idea that distinct biomolecules might be involved in antimony resistance in L. tropica field isolates.

Downregulation of Calcineurin Gene Is Associated with Glucantime(®) Resiatance in Leishmania infantum.

BACKGROUND: Pentavalent antimonials are the first line drugs for the treatment of leishmaniasis. Unresponsiveness of Leishmania spp. to antimonial drugs is a serious problem in some endemic areas. Investigations on molecular mechanisms involved in drug resistance are essential for monitoring and managing of the disease. Cal-cineurin is an essential protein phosphatase for number of signal transduction pathways in eukaryotic cells and it has a mediated role in apoptosis. This study aimed to determine of biomarker(s) in Glucantime(®) resiatance strain of L. infan-tum. METHODS: We used cDNA amplified fragment length polymorphism (cDNA-AFLP) and real time-RT PCR assays to compare gene expression profiles at the mRNA levels in resistant and susceptible L. infantum field isolates. RESULTS: The cDNA-AFLP results showed downlegulation of calcineurin in resis-tant isolate in comparison with susceptible one. Significant downregulation of cal-cineurin (0.42 fold) (P<0.05) was found in resistant isolate compared to susceptible one by Real time-RT PCR. CONCLUSION: This is the first report of calcineurin implication in Glucantime(®) drug resistance of field (natural) isolate of L. infantum. Downregulation of calcineurin could protect parasites from antimonial-induced apoptosis.