Biological Research最新文献

Background: Gastric cancer (GC) is a significant cancer-related cause of death worldwide. GC's most used chemotherapeutic regimen is based on platinum drugs such as cisplatin (CDDP). However, CDDP chemoresistance reduces the survival rate of advanced GC. The immune C-C chemokine receptor type 5 (CCR5) have been proposed as a pivotal factor in cancer progression since its blockade has been linked with antineoplastic effects on tumor cell proliferation; nevertheless, its role in the chemoresistance of GC has not been elucidated. This study aimed to determine the effects induced by the CCR5 using Maraviroc (MVC), a highly selective CCR5 antagonist, on CDDP-resistant AGS cells (AGS R-CDDP), tumoroids (3D tumor spheroids), and animal models.

Results: The combined CDDP and MVC treatment reduced cell viability and inhibited tumoroid formation in AGS R-CDDP cells. The effects of the MVC/CDDP combination on apoptosis and cell cycle progression were correlated with the increase in CDDP (dose-dependent). The mRNA levels of C-C Motif Chemokine Ligand 5 (CCL5), the main ligand for CCR5, decreased significantly in cells treated with the MVC/CDDP combination. MVC in the MVC/CDDP combination improved the survival rate and biochemical parameters of CDDP-treated mice by reducing the side effects of CDDP alone.

Conclusions: This finding suggests that MVC/CDDP combination could be a potential complementary therapy for GC.

Background: Protein palmitoylation, a critical posttranslational modification, plays an indispensable role in various cellular processes, including the regulation of protein stability, mediation of membrane fusion, facilitation of intracellular protein trafficking, and participation in cellular signaling pathways. It is also implicated in the pathogenesis of diseases, such as cancer, neurological disorders, inflammation, metabolic disorders, infections, and neurodegenerative diseases. However, its regulatory effects on sperm physiology, particularly motility, remain unclear. This study aimed to elucidate the mechanism by which protein palmitoylation governs sperm motility.

Methods: Protein palmitoylation in situ in mouse sperm was observed using innovative click chemistry. Sperm motility and motion parameters were evaluated using a computer-assisted sperm analyzer (CASA) after treatment with 2-bromopalmitic acid (2BP), a specific inhibitor of protein palmitoylation. Protein palmitoylation levels were confirmed by the acyl-biotin exchange (ABE) method. The interplay between protein palmitoylation, protein tyrosine phosphorylation, and intracellular calcium was investigated using Western blotting, ABE method, and fluorescent probes. The regulation of reactive oxygen species was also examined using fluorescent probes.

Results: Localized patterns and dynamics of protein palmitoylation in distinct sperm regions were revealed, including the midpiece, post-acrosomal region, acrosome, and head. Alterations in protein palmitoylation in sperm were observed under in vitro physiological conditions. Treatment with 2BP significantly affected sperm motility and motion parameters. The study revealed interactions between protein palmitoylation, including heat shock protein 90, and protein kinase A/protein kinase C-associated protein tyrosine phosphorylation and intracellular calcium. Additionally, protein palmitoylation was found to be involved in reactive oxygen species regulation.

Conclusions: Protein palmitoylation regulates sperm motility through calcium signaling, protein tyrosine phosphorylation, and reactive oxygen species. This study revealed the characteristics of protein palmitoylation in sperm and its role in regulating sperm motility, thereby providing novel insights into the causes of asthenozoospermia associated with sperm motility in humans.

Background: Acinetobacter baumannii poses a significant threat globally, causing infections primarily in healthcare settings, with high mortality rates. Its adaptability to antibiotic resistance and tolerance to various stresses, including reactive oxygen species (ROS), contribute to its persistence in healthcare environments. Previous evidence suggested that the periplasmic heat shock protein, HslJ-like protein (ABUW_2868), could be involved in oxidative stress defense in A. baumannii. In this study, we demonstrate the pivotal function of HslJ as the first line of defense against oxidative damage induced by hydrogen peroxide (H₂O₂).

Methods: An isogenic site-specific hslJ mutant of A. baumannii AB5075 was used to evaluate its sensitivity to H₂O₂, survival rate in human macrophages, biofilm, cell surface hydrophobicity, and motility. Additionally, the hslJ expression profile was measured under stress conditions and its OxyR-dependent regulation was assessed both in vitro and in a heterologous host.

Results: Herein, we report that HslJ is under the positive regulatory control of OxyR, which upregulates its expression in response to imipenem (IMP) and H₂O₂, thereby underscoring its importance in A. baumannii survival strategy. In addition, our findings revealed that the hslJ mutant displayed abrogated surface-associated motility accompanied by increased cell surface hydrophobicity (CSH), indicating also a role in maintaining cell membrane properties.

Conclusions: This comprehensive understanding of HslJ multifaceted role not only enriches our knowledge of A. baumannii stress response mechanisms but also provides valuable insights for developing targeted strategies to eradicate this deadly resilient pathogen in healthcare settings.

Background: Karyotype 46, XY female disorders of sex development (46, XY female DSD) are congenital conditions due to irregular gonadal development or androgen synthesis or function issues. Genes significantly influence DSD; however, the underlying mechanisms remain unclear. This study identified a Chinese family with 46, XY female DSD due to the CUL4B gene.

Methods: The proband medical history and pedigree were investigated. Whole-exome sequencing was performed to analyze different variations. Transiently transfected testicular teratoma (NT2/D1), KGN ovarian cells with either mutant or wild-type CUL4B gene, and knock-in Cul4b mouse models were confirmed. The expression levels of sex-related genes were analyzed.

Results: A 9.5-year-old girl was diagnosed with 46, XY DSD. A hemizygous variant c.838 T > A of the CUL4B gene was detected. The mRNA and protein levels of WNT4 and FOXL2 genes were higher than those in the wild-type group; however, CTNNB1, SOX9, and DMRT1 were lower in the wild-type group in NT2/D1 cells. In KGN ovarian cells of the mutant group, the mRNA and protein levels for WNT4 and CTNNB1 were elevated. Damaged testicular vasculature and underdeveloped seminal vesicles were observed in Cul4b^L337M mice.

Conclusions: A missense CUL4B variant c.838 T > A associated with 46, XY female DSD was identified, and may activate the Wnt4/β-catenin pathway. Our findings provide novel insights into the molecular mechanisms of 46, XY female DSD.

Background: Breast cancer is a leading cause of cancer-related mortality worldwide, with hereditary forms accounting for approximately 10% of cases. In Chile, significant gaps exist in genetic counseling and testing, particularly within the public health system. This study presents the implementation and outcomes of the first regional hereditary cancer program in the Maule region of Chile, aimed at improving detection and management of hereditary breast cancer.

Methods: A cohort of 48 high-risk breast cancer patients from the Hospital Regional de Talca received genetic counseling and underwent Next-Generation Sequencing multigene panel testing. The program was established through collaboration between multiple institutions, leveraging telemedicine and outsourcing sequencing analysis to address regional gaps.

Results: Pathogenic or likely pathogenic variants were identified in 12% of patients, including in BRCA1, BRCA2, TP53, and PALB2. Notably, novel pathogenic variants in BRCA1 (rs80357505) and TP53 (rs1131691022) were discovered, highlighting the unique genetic landscape of the Chilean population. Additionally, 70 variants of uncertain significance were found across 42 genes, particularly in FAN1, MSH6, and FANCI, underscoring the need for further research. The program's collaborative approach effectively bridged critical gaps in genetic services, providing high-quality care within the public health system despite limited resources.

Conclusions: The Regional Hereditary Cancer Program addresses significant gaps in genetic counseling and testing in Chile's public health system. This scalable model enhances early detection and personalized treatment for hereditary cancer patients and could be adapted to other regions across Latin America.

Connexins (Cxs) have the ability to form channels that allow the exchange of ions/metabolites between adjacent cells (gap junction channels, GJC) or between the intra- and extra-cellular compartments (hemichannels, HC). Cxs were initially classified as tumor suppressors. However, more recently, it has been shown that Cxs exert anti- and pro-tumorigenic effects depending on the cell and tissue context. In prostate cancer (PCa), the expression and functionality of Cxs remain highly controversial. Here, we analyzed the expression pattern of Cx26, Cx32, Cx37, Cx40, Cx43 and Cx45 in PCa cell lines with increasing levels of tumor aggressiveness (LNCaP < LNCaP-C4-2 < Du-145 < PC-3). In addition, GJ and HC activities were evaluated in the PCa cell lines using dye coupling and dye uptake assays, respectively. Lastly, the cellular localization of Cx26, Cx32, and Cx43 was analyzed in LNCaP and PC-3 cell lines using immunofluorescence analyses. Our results showed a positive association between the mRNA levels of Cx26, Cx37 and Cx45 and the degree of aggressiveness of PCa cells, a negative association in the case of Cx32 and Cx43, and no clear pattern for Cx40. At the protein level, a negative relationship between the expression of Cx26, Cx32 and Cx43 and the degree of aggressiveness of PCa cell lines was observed. No significant differences were observed for the expression of Cx37, Cx40, and Cx45 in PCa cell lines. At the functional level, only LNCaP cells showed moderate GJ activity and LNCaP and LNCaP-C4-2 cells showed HC activity. Immunofluorescence analyses confirmed that the majority of Cx26, Cx32, and Cx43 expression was localized in the cytoplasm of both LNCaP and PC3 cell lines. This data indicated that GJ and HC activities were moderately detected only in the less aggressive PCa cells, which suggest that Cxs expression in highly aggressive PCa cells could be associated to channel-independent roles.

The emergence of highly pathogenic avian influenza (HPAI) A H5N1 virus in dairy cattle marks a troubling new chapter in the ongoing battle against zoonotic diseases. Since its initial detection in 1955, the H5N1 virus has primarily been associated with poultry, posing significant threats to both animal and human health. However, recent outbreaks in U.S. dairy herds across nine states have revealed an alarming expansion of the virus, with over 190 herds affected as of September 2024. This unprecedented spread in cattle has sparked intense concern among scientists and health officials, especially with reports indicating that up to 20% of dairy products may contain traces of the virus. The implications of the H5N1 virus establishing itself in cattle populations are profound. This potential endemic presence could transform dairy farms into reservoirs of the virus, facilitating its evolution and increasing the risk of human transmission. Mutations enhancing viral replication in mammals have already been identified, including the notorious PB2 E627K mutation linked to increased virulence. Moreover, the detection of the virus in the central nervous system of infected animals, including cats, underscores the broad tissue tropism and severe pathogenic potential of the H5N1 virus. Current containment efforts include stringent biosecurity measures and financial incentives for enhanced testing and personal protective equipment (PPE) for farmers. Yet, gaps in testing infrastructure and the resurgence of raw milk consumption pose significant challenges. The U.S. Department of Agriculture (USDA) and the Centers for Disease Control and Prevention (CDC) emphasize the critical need for comprehensive testing and pasteurization to mitigate the risk of human infection. As the scientific community races to adapt existing antiviral treatments and develop effective vaccines, the concept of a One Health approach becomes increasingly vital. This holistic strategy calls for coordinated actions across human, animal, and environmental health sectors to preemptively tackle emerging zoonotic threats. Strengthening surveillance, fostering international cooperation, and investing in research are essential steps to prevent the H5N1 virus from igniting the next global health crisis. The current avian influenza outbreak serves as a stark reminder of the delicate balance between human activities and viral evolution. Our collective ability to respond effectively and proactively will determine whether we can avert the perfect storm brewing on the horizon.

NADPH oxidases (NOX) are membrane-bound proteins involved in the localized generation of reactive oxygen species (ROS) at the cellular surface. In cancer, these highly reactive molecules primarily originate in mitochondria and via NOX, playing a crucial role in regulating fundamental cellular processes such as cell survival, angiogenesis, migration, invasion, and metastasis. The NOX protein family comprises seven members (NOX1-5 and DUOX1-2), each sharing a catalytic domain and an intracellular dehydrogenase site. NOX-derived ROS promote invadopodia formation, aberrant tyrosine kinase activation, and upregulation of matrix metalloproteinases (MMPs). Specifically, NOX5 modulates adhesion, motility, and proteolytic activation, while NOX1 likely contributes to invadopodia formation and adhesive capacity. NOX2 and NOX4 are implicated in regulating the invasive phenotype, expression of MMPs and EMT markers. DUOX1-2 participate in epithelial-mesenchymal transition (EMT), crucial for invasive phenotype development. Soluble molecules such as TGF-β and EGF modulate NOX protein activation, enhancing cell invasion through localized ROS production. This review focuses on elucidating the specific role of NOX proteins in regulating signaling pathways promoting cancer cell spread, particularly EMT, invadopodia formation and invasive capacity.

Introduction: Chile has achieved developed nation status and boasts a life expectancy of 81 + years; however, the healthcare and research systems are unprepared for the social and economic burden of cancer. One decade ago, the authors put forward a comprehensive analysis of cancer infrastructure, together with a series of suggestions on research orientated political policy.

Objectives: Provide an update and comment on policy, infrastructure, gender equality, stakeholder participation and new challenges in national oncology. Assess the funding and distribution of cancer investigation. Present actions for the development of oncology research, innovation and patient care.

Methods: Triangulating objective system metrics of economic, epidemiological, private and public sector resources together with policy analysis, we assessed cancer burden, infrastructure, and investigation. We analyzed governmental and private-sector cancer databases, complemented by interviews with cancer stakeholders.

Results: Governmental policy and patient advocacy have led to the recognition of cancer burden, a cancer law, and a national cancer plan. Cancer has become the leading cause of death in Chile (59,876 cases and 31,440 cancer deaths in 2022), yet only 0.36% gross domestic product (GDP) is directed to research and development. Inequalities in treatment regimens persist. Prevention policy has lowered tobacco consumption, sugar intake via soft drinks and offered a high coverage of HPV vaccines. A high-quality cancer research community is expanding, and internationally sponsored clinical oncology trials are increasing.

Conclusions: The cancer law has facilitated advancement in policy. Prevention policies have impacted tobacco and sugar intake, while gender equality and care inequality have entered the public forum. Cancer research is stagnated by the lack of investment. Implementation of a cancer registry and biobanking, reinforcement of prevention strategies, development of human resources, promotion of clinical trial infrastructure and investment in new technologies must be placed as a priority to permit advancements in innovation and equitable cancer care.

Background: Assam's aromatic Joha rice is a unique rice class famous for its aroma, taste, and nutritional benefits, which fetch high market prices in domestic and international markets. Joha landraces are inherently poor yielders due to their strong aroma and predominantly photoperiod sensitivity. Hybridization involving non-aromatic HYVs improves yield with concomitant loss of quality. In this context, mutation breeding, a sustainable approach where genetic mutations are induced to create desirable traits, often provides useful allelic variation in specific morpho-agronomic traits. The present study delves into the genetic characterization of a photoperiod-insensitive mutant. As part of our mutation breeding programme, this mutant was isolated from a gamma ray-induced M₂ population of a Joha rice landrace, Kon Joha.

Results: The mutant was unique, and a single recessive gene conditions the induced photoperiod insensitivity. Mutant gene tagging involved 402 SSR and InDel markers, and later polymorphic markers were used for bulk segregant analysis (BSA) in the F2 population of 'mutant × Kalijeera (distant parent)'. BSA revealed an association between the SSR marker RM527 and this mutant trait. This marker is present on chromosome 6 of the rice genome. Using chromosome 6-specific SSR markers in polymorphic screening and BSA revealed another associated marker, RM19725, for the mutant trait. The genomic interval between RM527 and RM19725 harbors a photoperiod-insensitive gene, Hd1, on chromosome 6. Cloning and sequencing of Hd1 genomic fragments from the parents and mutants revealed a single-base deletion in exon 2, leading to a frameshift mutation in the Hd1 protein. This mutation in exon 2 leads to severe structural abnormalities in the CCT domain of the Hd1 protein that is critical for the interaction of the repressing complex with conserved response elements in the florigen gene under long-day conditions, thereby causing photoperiod insensitivity.

Conclusions: The mutant's pleasant aroma and other quality characteristics, comparable to those of the parent cultivar, hold significant promise. They expand its potential use in a structured breeding programme aimed at developing high-value aromatic Joha rice. This rice, resilient to winter- and summer-growing environments and with broad seasonal adaptability, could revolutionize the rice market. The practical value of our research is underscored by this exciting possibility.