Avicenna journal of medical biotechnology最新文献

Computer-aided drug designing is a promising approach to defeating the dry pipeline of drug discovery. It aims at reduced experimental efforts with cost-effectiveness. Naturally occurring large molecules with molecular weight higher than 500 Dalton such as cationic peptides, cyclic peptides, glycopeptides and lipopeptides are a few examples of large molecules which have successful applications as the broad spectrum antibacterial, anticancer, antiviral, antifungal and antithrombotic drugs. Utilization of microbial metabolites as potential drug candidates incur cost effectiveness through large scale production of such molecules rather than a synthetic approach. Computational studies on such compounds generate tremendous possibilities to develop novel leads with challenges to handle these complex molecules with available computational tools. The opportunities begin with the desired structural modifications in the parent drug molecule. Virtual modifications followed by molecular interaction studies at the target site through molecular modeling simulations and identification of structure-activity relationship models to develop more prominent and potential drug molecules. Lead optimization studies to develop novel compounds with increased specificity and reduced off targeting is a big challenge computationally for large molecules. Prediction of optimized pharmacokinetic properties facilitates development of a compound with lower toxicity as compared to the natural compounds. Generating the library of compounds and studies for target specificity and ADMET (Absorption, Distribution, Metabolism, Excretion and Toxicity) for large molecules are laborious and incur huge cost and chemical wastage through in-vitro methods. Hence, computational methods need to be explored to develop novel compounds from natural large molecules with higher specificity. This review article is focusing on possible challenges and opportunities in the pathway of computer-aided drug discovery of large molecule therapeutics.

Background: The screen of Polyketide Synthase (PKS) and Nonribosomal Peptide Synthetase (NRPS) gene groups is a quick way to discover new therapeutic agents. However, errors in laboratory techniques cause a loss of touch with reality. This study aimed to evaluate the presence of PKS and NRPS gene groups in previously isolated strains by optimizing their specialized amplification by degenerate primers and indicating the evolutionary relationships with reference strains.

Methods: PKS-I, II, and NRPS genes PCR amplification was performed using three degenerate primer sets for 22 actinomycete strains with antibacterial activity. Annealing temperature and the amount of template DNA and primers were optimized. PCR products of PKS-I, II, and NRPS from three strains were sequenced after TA cloning. Besides, strains with high antibacterial activity were identified by biochemical features and partial 16S rDNA sequencing and hypothetically classified by a phylogenetic tree.

Results: High frequencies of PKS-I (86.4%), PKS-II (81.8%), and NRPS (95.4%) genes were found among the strains after optimization. Fourteen strains (64%) contained all of the genes, and 100% of strains had at least two genes. These numbers are pretty distinct in comparison with the previous researches. All of the sequenced strains were members of Streptomyces genus.

Conclusion: Our research showed that degenerate PCR strongly depends on the variation of annealing temperature and primer concentration, resulting in an unexpected shift in PCR outputs. The sequencing results confirmed the optimized conditions for specialized PCR of PKS-I, PKS-II, and NRPS gene groups.

Background: Uncontrolled mitosis of cancer cells and resistance cells to chemotherapy drugs are the challenges of prostate cancer. Thalicthuberine causes a mitotic arrest and a reduction of the effects of drug resistance, resulting in cell death. In this study, we applied bioinformatics and computational biology methods to identify functional pathways and side effects in response to Thalicthuberine in prostate cancer patients.

Methods: Microarray data were retrieved from Gene Expression Omnibus (GEO), and protein-protein interactions and gene regulatory networks were constructed, using the Cytoscape software. The critical genes and molecular mechanisms in response to Thalicthuberine and its side effects were identified, using the Cytoscape software and WebGestalt server, respectively. Finally, GEPIA2 was used to predict the relationship between critical genes and prostate cancer.

Results: The POLQ, EGR1, CDKN1A, FOS, MDM2, CDC20, CCNB1, and CCNB2 were identified as critical genes in response to this drug. The functional mechanisms of Thalicthuberine include a response to oxygen levels, toxic substances and immobilization stress, cell cycle regulation, regeneration, the p53 signaling pathway, the action of the parathyroid hormone, and the FoxO signaling pathway. Besides, the drug has side effects including muscle cramping, abdominal pains, paresthesia, and metabolic diseases.

Conclusion: Our model suggested newly predicted crucial genes, molecular mechanisms, and possible side effects of this drug. However, further studies are required.

Background: The Mattan tailam mixture has been extensively used to heal ulcerous wounds in traditional Siddha practice. The present study aimed to synthesize a Mattan tailam nanogel and evaluate the enhancement of wound healing potential in an experimental wound model.

Methods: Mattan tailam nanogel was synthesized using the high-energy milling approach, and characterization of nanogel and potency of wound healing was investigated. The novelty of this study was the nanogel preparation of Mattan tailam.

Results: As expected, a synthesized novel nanogel of Mattan tailam has a distinct, prominent peak with a spherical form, is negatively charged and has an average particle size of 20-30 nm. Mattan tailam nanogel treated rats showed a remarkable reduction (p<0.001) in the wound area. On the 16^th day, 10% Mattan tailam nanogel treatment resulted in a higher percentage of wound contraction. The 10% Mattan tailam nanogel group exhibited a faster epithelialization time (14.33 days) and a greater hydroxyproline concentration than the others. The topical application of 10% Mattan tailam nanogel increased tensile strength, signifying a better therapeutic indication.

Conclusion: The present findings prove that polyherbal Mattan tailam nanogel formulation significantly improves collagen production, wound contraction, and tensile strength.

Background: WWTR1 or TAZ is a transcriptional co-activator protein expressed in cytoplasm which functions as the main downstream effector of the Hippo signaling pathway. This pathway is an evolutionally conserved signal cascade, which plays a pivotal role in organ size control and tumorigenesis. Ectopic expression of TAZ has already been observed in many malignancies, while the ectopic localization of TAZ is reported for the first time. The aim of this study was to produce a specific monoclonal antibody (mAb) against a synthetic peptide derived from WWTR1 protein to be used as a research tool in human carcinomas.

Methods: A 21-mer synthetic peptide (derived from human TAZ protein) was used for immunization of BALB/c mice after conjugation with Keyhole Limpet Haemocyanin (KLH) using hybridoma technology. The generated mAb reacted with the immunizing peptide employing ELISA assay. The reactivity of the antibody with native TAZ protein was assessed through Western blot, immunocytochemistry, and flow cytometry using different cancer cell lines.

Results: The produced mAb could recognize the immunizing peptide in ELISA and K_aff was 0.6×10^-9 M. The produced anti-TAZ mAb unlike available commercial anti-TAZ antibody, was capable of specifically recognizing cell surface TAZ in human carcinoma cell lines including MCF-7, Raji, and A431 in Western blot, immunocytochemistry, and flow cytometry assays. As expected, no reactivity was observed using normal Peripheral Blood Mononuclear Cell (PBMC) from healthy donors.

Conclusion: Based on the results, TAZ is ectopically expressed on the surface of tumor cell lines which is not the case in normal cells. The generated mAb has a potential to be used as a research tool in studying the expression of TAZ in human carcinomas in different applications.

Background: Despite the significant progress in the treatment of Acute Lymphoblastic Leukemia (ALL) in children, it still remains as one of the most challenging malignancies in adults. Identification of new biomarkers may improve the management of adult ALL. Proteins expressed on the cell surface can be considered as disease-associated biomarkers with potential for diagnosis and targeted therapies. Thus, membrane proteome studies give essential information about the disease-related biomarkers.

Methods: We applied 2-dimensional blue-native SDS-PAGE technique followed by MALDI-TOF/TOF-mass spectrometry to study the cell membrane proteome of peripheral blood mononuclear cells of adult B-ALL patients in comparison to that of the healthy controls.

Results: Sixty seven differentially expressed protein spots were detected, among them 52 proteins were found to be up-regulated but the other 15 proteins were down-regulated in B-ALL. Five differentially expressed proteins, involved in energy metabolism pathways, were detected in B-ALL patients compared to the healthy control group.

Conclusion: Differentially expressed proteins provide an insight into the molecular biology of B-ALL. Further studies must be done to confirm our data to be considered as potential targets for detection and treatment of B-ALL.

Glioblastoma (GBM) is the most common and aggressive primary malignant brain tumor with poor prognosis and high potential of dispersion to other brain tissues in adult. Effective and modern choices of treatment including chemotherapy with alkylating agents marginally extend survival of GBM. However, alkylating agents can lead to highly harmful mismatch during DNA replication causing apoptosis and cell death. Accordingly, O6-Methylguanine-DNA methyltransferase (MGMT) removes alkyl adducts, thereby causing resistance to alkylating drugs. Single-Nucleotide Polymorphisms (SNPs) in MGMT promoter region may play a role in the regulation of MGMT expression and prediction of glioma development risk. In order to evaluate the clinical significance of rs1625649 SNP in the MGMT promoter region of glioblastoma, genomic DNA from a series of 54 patients with GBM and 50 healthy individuals in Iranian population were collected for tetra ARMS PCR amplification. None of the "A" or "C" alleles were associated with tumor occurrence, the "AA" genotype was more frequent in healthy subjects, and the "AC" genotype was 4.6 times more common in patients with GBM. The longest survival time was observed in the "CC" genotype; however, this difference was not statistically significant. On the other hand, homozygous rs1625649 (AA genotype) was significantly associated with a better survival than the cases with heterozygous rs1625649 (CA genotype) or wild type rs1625649 (CC genotype), predicting better response to temozolomide-based chemotherapy.