Molecular Biology Reports最新文献

Background: Foot-and-mouth disease (FMD) remains a major constraint to livestock productivity in Pakistan, particularly in Khyber Pakhtunkhwa (KP), where recurrent outbreaks cause substantial economic losses. Despite routine biannual vaccination, the continued circulation of FMD virus (FMDV) serotype A predominantly the A-Iran-05 lineage raises concerns regarding antigenic mismatch between field strains and vaccine formulations.

Methods: Results A total of 244 epithelial tissue samples were collected from clinically infected cattle and buffaloes across four districts of KP. Of these, 226 samples were confirmed positive for FMDV serotype A by RT-PCR, and 215 VP1 gene sequences were successfully obtained. Phylogenetic analysis revealed that all isolates clustered within the A-Iran-05 lineage and were genetically distinct from the vaccine strain A22/Iraq/64. Antigenic relationship analysis demonstrated low r₁-values (< 0.39), indicating poor antigenic matching and suggesting reduced vaccine effectiveness. Epidemiological analysis identified age (2-4 years) as a significant risk factor for infection, while no significant associations were observed with sex, species, vaccine brand, or clinical severity.

Conclusions: The dominance of antigenically divergent FMDV serotype A strains in KP highlights the limitations of current vaccine formulations. Continuous molecular surveillance and the development of region-specific vaccines are essential to improve FMD control strategies in endemic regions of Pakistan.

Background: Klebsiella pneumoniae exhibits a marked propensity for acquiring beta-lactam resistance genes. Among these, AmpC beta-lactamases are able to hydrolyze a broad spectrum of antibiotics including first- through third-generation cephalosporins, cephamycins, and aztreonam. The CIT, EBC, and DHA families are among the most clinically significant plasmid-mediated AmpC variants in this pathogen. Consequently, this study aimed to investigate the prevalence of genes encoding these specific enzymes among clinical isolates of K. pneumoniae in northern Iran.

Methods: One hundred clinical isolates were collected from hospitalized patients and identified using standard microbiological and biochemical assays. The antimicrobial resistance profile of each isolate was determined via the disk agar diffusion method. Subsequently, PCR test was employed to detect the presence of the bla_CIT, bla_EBC, and bla_DHA genes.

Results: The mean age of the patients (58 females and 42 males) was 50.31 years. Isolates were sourced from patients in general (41%), pediatric (45%), burn (7%), and infectious (7%) hospitals. The primary specimen sources were urine (64%), blood (10%), tissue (15%), wound (7%), and sputum (4%). The highest prevalence of resistance (93%) was observed against ampicillin-sulbactam, whereas 73% of isolates remained susceptible to ertapenem.

Conclusion: The high ampicillin-sulbactam resistance represents a serious concern for the management of hospital-acquired infections. Furthermore, while the presence of the investigated bla_CIT, bla_EBC, and bla_DHA genes did not show a statistically significant correlation with resistance to most tested antibiotics, their detection remains of potential clinical importance due to the risk of horizontal gene transfer to other bacterial species.

Purpose: Breast cancer is a significant global health issue, with resistance to doxorubicin (DOX) posing a major challenge to effective treatment. SUMOylation, a post-translational modification process, is linked to cancer progression and therapy resistance. PIAS4, a SUMO E3 ligase involved in maintaining genome stability and stress response, may play a role in these mechanisms. However, its function in breast cancer progression and DOX resistance remains uncertain. This study investigates the potential role of PIAS4 in mediating DOX resistance in breast cancer.

Methods and results: Naked mole-rats (NMRs) are cancer-resistant rodents with improved genome maintenance, yet the role of SUMOylation in this trait remains unclear. SUMOylation machinery gene expression levels are investigated using qPCR in NMR tissue in comparison with carcinogenic breast cancer (MCF-7) cell line. Functional studies are performed in MCF-7 cells overexpressing PIAS4 to demonstrate effects on proliferation, invasion, drug sensitivity, and protein expression in the presence and absence of DOX treatment. While most SUMOylation genes were expressed at low levels in NMR intestinal tissues, PIAS4 showed higher expression compared to MCF-7 cells. PIAS4 overexpression in MCF-7 cells significantly decreases colony formation, invasiveness, and resistance to DOX. Western blot analysis showed downregulated Bcl-2 protein levels after DOX treatment, indicating a potential role in apoptosis evasion.

Conclusion: PIAS4 expression level plays a role in breast cancer cell survival, invasiveness, and chemoresistance, partly by altering anti-apoptotic pathways. These findings position PIAS4 as a potential biomarker and therapeutic target for overcoming resistance to anthracycline-based therapies in breast cancer.

Background: Leukemia remains a major therapeutic challenge due to frequent treatment resistance and relapse. Novel agents that preferentially target leukemic cells are urgently needed. Papain, a cysteine protease derived from Carica papaya, has been reported to exhibit antioxidant, anti-inflammatory, and anticancer properties; however, its molecular effects in leukemia cells remain poorly understood.

Objectives: This study aimed to evaluate the antileukemic effects of papain on HL-60 and K562 cells, focusing on apoptosis induction, cell-cycle regulation, inflammatory modulation, and gene/protein expression changes.

Methods: HL-60 and K562 cells were treated with papain at 123 µM and 386-483 µM, respectively, for 24-48 h. Concentrations were selected based on IC₂₅ values for HL-60 and IC₅₀ values for K562 obtained from viability assays. Cell viability was assessed using the MTS assay. Apoptosis, cell-cycle distribution, and surface expression of **Sema3A-a semaphorin family member involved in immune regulation and leukemic cell signaling-**were analyzed using flow cytometry. RT-qPCR quantified expression of apoptosis-related genes (P53, PTEN, BAX, CASP3, BCL-2, AKT-1, NF-κB), and ELISA measured Cytochrome c, Cleaved Caspase-3, TNF-α, IL-6, IL-10, GPX4, and ACSL4.

Results: Papain significantly reduced cell viability in both cell lines in a dose- and time-dependent manner. Increased Cytochrome c and Cleaved Caspase-3 levels suggested apoptosis induction. Papain exposure led to predominant accumulation of cells in the G₀/G₁ phase accompanied by a reduction in the G₂/M population in HL-60 cells, whereas in K562 cells it induced a significant and dose-dependent accumulation in the S phase rather than G₂/M arrest. Papain induced significant alterations in apoptosis-related gene expression in both leukemia cell lines. These changes reflected activation of apoptotic signaling pathways rather than a uniform dose-dependent or directionally consistent transcriptional pattern. Furthermore, papain significantly downregulated Sema3A surface expression and altered cytokine profiles, increasing TNF-α and IL-10 in both cell lines and IL-6 in K562 cells.

Conclusion: Papain exhibits antileukemic effects in vitro, associated with mitochondrial-mediated apoptosis, altering cell-cycle progression, suppressing Sema3A expression, and modulating inflammatory responses. These findings suggest that papain may represent a candidate for further preclinical investigation in leukemia models.

Background: The ATP9A gene encodes a P4-type ATPase involved in phospholipid translocation, essential for vesicular trafficking and neuronal development. Pathogenic ATP9A variants cause autosomal recessive neurodevelopmental disorders characterized by intellectual disability and microcephaly, yet the impact of missense variants remains poorly understood.

Methods: A 7-year-old female patient with cognitive impairment, microcephaly, and developmental delay was admitted to Başakşehir Çam and Sakura City Hospital. Whole exome sequencing (WES) using Illumina technology identified a novel homozygous ATP9A variant, confirmed by Sanger sequencing and segregation analysis. In silico tools (RosettaFold, DynaMut, mCSM, SDM, DUET, AggreScan3D) assessed its structural impact. Quantitative real-time polymerase chain reaction (RT-qPCR) was conducted to evaluate the relative expression levels of ATP9A.

Results: WES revealed a homozygous missense variant, ATP9A: NM_006045.3:c.1091G > C:p.(Arg364Thr), classified as variant of uncertain significance based on ACMG guidelines (PP2, PM2, PM3). Protein modeling demonstrated reduced stability (ΔΔG = - 1.51 to - 0.26 kcal/mol), increased flexibility, and a 2.4-fold decrease in solvent accessibility. The variant disrupted polar and hydrophobic interactions within the P-type ATPase IV domain, thereby increasing aggregation propensity. Expression analysis revealed elevated ATP9A mRNA levels, suggesting a compensatory cellular response.

Conclusion: This novel ATP9A variant broadens the mutational spectrum of ATP9A-related neurodevelopmental disorders. Structural destabilization of the p.(Arg364Thr) protein may contribute to the patient's cognitive impairment and microcephaly, warranting further functional studies.