Evasion Of Apoptosis Research Articles

Prostate Cancer-Specific Lysine 53 Acetylation of Cytochrome c Drives Metabolic Reprogramming and Protects from Apoptosis in Intact Cells.

Cytochrome c (Cytc) is important for both mitochondrial respiration and apoptosis, both of which are altered in cancer cells that switch to Warburg metabolism and manage to evade apoptosis. We earlier reported that lysine 53 (K53) of Cytc is acetylated in prostate cancer. K53 is conserved in mammals that is known to be essential for binding to cytochrome c oxidase and apoptosis protease activating factor-1 (Apaf-1). Here we report the effects of this acetylation on the main functions of cytochrome c by expressing acetylmimetic K53Q in cytochrome c double knockout cells. Other cytochrome c variants analyzed were wild-type, K53R as a control that maintains the positive charge, and K53I, which is present in some non-mammalian species. Intact cells expressing K53Q cytochrome c showed 49% decreased mitochondrial respiration and a concomitant increase in glycolytic activity (Warburg effect). Furthermore, mitochondrial membrane potential was decreased, correlating with notably reduced basal mitochondrial superoxide levels and decreased cell death upon challenge with H2O2 or staurosporine. To test for markers of cancer aggressiveness and invasiveness, cells were grown in 3D spheroid culture. K53Q cytochrome c-expressing cells showed profoundly increased protrusions compared to WT, suggesting increased invasiveness. We propose that K53 acetylation of cytochrome c is an adaptive response that mediates prostate cancer metabolic reprogramming and evasion of apoptosis, which are two hallmarks of cancer, to better promote tumor survival and metastasis.

NAC1 transcriptional activation of LDHA induces hepatitis B virus immune evasion leading to cirrhosis and hepatocellular carcinoma development

Our study aimed to elucidate the molecular mechanisms underlying NAC1 (nucleus accumbens associated 1) transcriptional regulation of LDHA and its role in HBV immune evasion, thus contributing to the development of cirrhosis and hepatocellular carcinoma (HCC). Utilizing public datasets, we performed differential gene expression and weighted gene co-expression network analysis (WGCNA) on HBV-induced cirrhosis/HCC data. We identified candidate genes by intersecting differentially expressed genes with co-expression modules. We validated these genes using the TCGA database, conducting survival analysis to pinpoint key genes affecting HBV-HCC prognosis. We also employed the TIMER database for immune cell infiltration data and analyzed correlations with identified key genes to uncover potential immune escape pathways. In vitro, we investigated the impact of NAC1 and LDHA on immune cell apoptosis and HBV immune evasion. In vivo, we confirmed these findings using an HBV-induced cirrhosis model. Bioinformatics analysis revealed 676 genes influenced by HBV infection, with 475 genes showing differential expression in HBV-HCC. NAC1 emerged as a key gene, potentially mediating HBV immune escape through LDHA transcriptional regulation. Experimental data demonstrated that NAC1 transcriptionally activates LDHA, promoting immune cell apoptosis and HBV immune evasion. Animal studies confirmed these findings, linking NAC1-mediated LDHA activation to cirrhosis and HCC development. NAC1, highly expressed in HBV-infected liver cells, likely drives HBV immune escape by activating LDHA expression, inhibiting CD8 + T cells, and promoting cirrhosis and HCC development.

Unlocking the Therapeutic Potential of BCL-2 Associated Protein Family: Exploring BCL-2 Inhibitors in Cancer Therapy.

Apoptosis, programmed cell death pathway, is a vital physiological mechanism that ensures cellular homeostasis and overall cellular well-being. In the context of cancer, where evasion of apoptosis is a hallmark, the overexpression of anti-apoptotic proteins like Bcl2, Bcl-XL, and Mcl-1 has been documented. Consequently, these proteins have emerged as promising targets for therapeutic interventions. The BCL-2 protein family is central to apoptosis and plays a significant importance in determining cellular fate serving as a critical determinant in this biological process. This review offers a comprehensive exploration of the BCL-2 protein family, emphasizing its dual nature. Specifically, certain members of this family promote cell survival (known as anti-apoptotic proteins), while others are involved in facilitating cell death (referred to as pro-apoptotic and BH3-only proteins). The potential of directly targeting these proteins is examined, particularly due to their involvement in conferring resistance to traditional cancer therapies. The effectiveness of such targeting strategies is also discussed, considering the tumor's propensity for anti-apoptotic pathways. Furthermore, the review highlights emerging research on combination therapies, where BCL-2 inhibitors are used synergistically with other treatments to enhance therapeutic outcomes. By understanding and manipulating the BCL-2 family and its associated pathways, we open doors to innovative and more effective cancer treatments, offering hope for resistant and aggressive cases.

Multiple Myeloma

The second most common hematologic malignancy is the clonal proliferation of neoplastic plasma cells within the bone marrow. There is the presence of monoclonal immunoglobulins in the serum and/or urine. This results in anemia, myelosuppression, bone destruction, and clinical consequences of para-proteinemia on kidney function and other organ systems. The disease manifests through the acronym CRAB (hypercalcemia, renal impairment, anemia, and bone lesions). Less frequent manifestations of multiple myeloma are of extramedullary localizations. Myeloma cells can become independent of the bone marrow microenvironment, circulate freely in the blood, and infiltrate organs. This results in a high-risk state characterized by increased proliferation, evasion of apoptosis, and treatment resistance. It can affect any area of tissue. Most commonly it involves the pleura, lymph nodes, chest wall, liver, skin/soft tissue, lungs, CNS, genitourinary system, breast and pancreas. In patients with confirmed multiple myeloma, the diagnosis of extramedullary involvement is typically established by the presence of pathological soft tissue masses using radiological methods such as computed tomography (CT) scan, positron emission tomography/CT (PET/CT), magnetic resonance imaging (MRI), or ultrasound, along with biopsy or physical examination. The molecular mechanisms underlying the development of extramedullary multiple myeloma (EMM) have not been fully defined. Various cytogenetic abnormalities are observed, and some studies have generated genomic sequencing profiles that distinguish EMM from classic multiple myeloma. While plasma cell leukemia (PCL) and central nervous system (CNS) EMM indicate a poor prognosis, outcomes for other manifestations can be highly heterogeneous. Sensitive imaging modalities including PET/CT and MRI (Fig.1) are integral components of diagnosis and response assessment. Patients with extramedullary multiple myeloma (EMM) have a clear survival disadvantage.

Apoptosis and Autophagy: Therapeutic Implications in Cancer

Despite the advances in the medical field so far, cancer remains a global health priority even now. Considering the drug resistance and the failure of cancer therapies to achieve complete eradication of cancer cells in certain populations, developing molecules that induce programmed cell death or apoptosis has been the focus of cancer research for several decades. Apoptosis evasion is one of the hallmarks of cancer cells, and efforts continue to achieve complete annihilation of cancer cells through selective killing. On the other hand, autophagy, a mode of cell degradation, is considered a double-edged sword. Recent studies show that autophagy also can be manipulated to selectively target cancer cells based on the tumor microenvironment and cellular context. Studies show that autophagy is an evolutionarily conserved process initiated during stress response and has enormous importance in maintaining physiological balance. Most importantly, the dynamic equilibrium between apoptosis and autophagy is crucial in maintaining cellular homeostasis. Although a ‘cell eating’ process, the fate of autophagic cells depends entirely on the nature of stress and the extent of crosstalk between autophagy. This understanding is of immense significance when designing therapeutic interventions targeting apoptosis and autophagy. Currently, several studies are ongoing to gain insights into the role of autophagy in cancer initiation, invasion, progression, angiogenesis, and metastasis. This review focuses on the two major cell death mechanisms, apoptosis and autophagy, in the context of cancer, their crosstalk, and the therapeutic interventions targeting both modes of cell death.

Abstract 2744: Exploring the role of the MSLN/MUC16 interaction in cancer progression via the in situ proximity ligation technique

Abstract Introduction: Mesothelin (MSLN) is a glycoprotein present on the surface of mesothelial cells, sometimes used as a tumor marker. Its overexpression in various cancers, including mesothelioma, ovarian, pancreatic, and lung, is linked to increased tumor aggressiveness, evasion of apoptosis, metastasis, and resistance to treatments. Mucin16 (MUC16) belongs to a family of proteins that play a crucial role in cell adhesion, signaling, and immune responses. In cancer, alterations in mucin expression and structure may contribute to tumor progression and metastasis by enhancing cell survival and immune evasion. Mesothelin is known to interact with mucins, influencing tumor cell behavior and metastatic potential. More specifically, the MSLN/MUC16 interaction facilitates tumor cell invasion and peritoneal spread in ovarian cancer. However, reliable molecular tools to study protein interactions have been scarce. Here, we relied on the Naveni® in situ proximity ligation technology to identify MSLN/MUC16 in various cancer samples. The method detects proteins located within interaction range (<40 nm) by means of antibodies conjugated to oligonucleotides that create amplified fluorescent signal. Since the technique does not compromise the structural integrity of tissues, communication between proteins can be studied in their native environment. Materials & Methods: Human FFPE tissue microarrays (TMA) with ovarian primary carcinoma and matched metastatic cancer (80 cores) and ovarian cancer tissue with normal tissue (100 cores) were deparaffinized and subjected to standard heat-induced antigen retrieval and blocking. Staining against the MSLN/MUC16 interaction was performed with the NaveniFlex Tissue MR Atto647N kit (Navinci Diagnostics). Co-staining antibodies against pan-Cytokeratin and Ki67 were included in the detection mix. Immunofluorescence (IF), using the same MSLN and MUC1 primary antibodies, was completed on an additional slide of each TMA, and then secondary antibodies conjugated to Alexa Fluor™ 488 and 594 were used for detection. Imaging was performed on an Olympus scanner VS200. Results & Discussion: In this study, we showed that the interaction is abundant in ovarian cancer, with a distinguishable difference in the signal presence between cancerous and normal adjacent tissue. Furthermore, the additional tumor marker co-stainings give insights into the tumor invasion and growth. When comparing the Naveni® signal of MSLN/MUC16 against IF staining of each, the Naveni® signal shows true interactions, as opposed to expression patterns. Understanding the roles of mesothelin and mucin in cancer, both individually and in interaction, is crucial for developing targeted therapies and diagnostic tools. Further research on their interaction and specific molecular pathways triggered by it is essential for devising effective strategies to combat cancer progression. Citation Format: Sara Bodbin, Doroteya Raykova, Agata Zieba-Wicher. Exploring the role of the MSLN/MUC16 interaction in cancer progression via the in situ proximity ligation technique [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2744.

Abstract 1829: Brusatol overcomes tyrosine kinase inhibitors resistance in myeloid leukemia cells by inhibiting translation of fast turnover protein cyclin D1 and Mcl-1

Abstract Myeloid leukemia is characterized with fast proliferation and apoptosis evasion, which are controlled by mutant or activated tyrosine kinase signalings. Tyrosine kinase inhibitors (TKI) targeting BCR-ABL in chronic myeloid leukemia (CML) and FLT3-ITD in acute myeloid leukemia (AML) significantly improved the therapy, but not cure, due to the general resistance. Overactivated mTOR protein translation pathway is believed to be one of the mechanisms causing resistance and that targeting protein translation should be one effective approach to overcome resistance. Brusatol is a quassinoid extracted from the fruit of Brucea javanica and an inhibitor of protein translation. We tested its antiproliferation and apoptosis induction in a variety of AML and CML cell lines as well as in TKI resistant cell lines. Brusatol effectively inhibits the growth of seven leukemia cell lines with GI50 values less than 20 nM. Brusatol induces apoptosis in AML cell lines and induces G0/G1 phase arrest in CML cell lines. Brusatol decreases the levels of fast turnover protein cyclin D1 and Mcl-1. In FLT3-ITD inhibitor sorafenib resistant MOLM-13/Sor cell line brusatol exhibits similar growth inhibition and apoptosis induction with the parental MOLM-13 cells, associated with inhibition of Mcl-1 and FLT3-ITD proteins. In BCR-ABL inhibitor imatinib resistant K562/STI cell line brusatol is effective as in parental K562 cells, associated with inhibition of cyclin D1 and BCR-ABL proteins. Brusatol at 2 mg/kg effectively inhibit tumor growth of K562 xenografts without causing toxicity to normal organs. These data indicate that brusatol inhibits oncogenic protein translation and has potential to be used to treat TKI resistant leukemia. Citation Format: Huiming Hua, Ying Yang, Guangfuxin Lin, Jingyi Zhang, Samuel Waxman, Yongkui Jing. Brusatol overcomes tyrosine kinase inhibitors resistance in myeloid leukemia cells by inhibiting translation of fast turnover protein cyclin D1 and Mcl-1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1829.

Abstract 2988: TUG1 exosomal lncRNA sponges let-7 miRNA family members and advances prostate cancer

Abstract Exosomal long-non coding RNAs (lncRNAs) play an important role in cancer progression and have potential prognostic biomarker potential in several cancers including prostate cancer (PCa). Taurine-upregulated gene 1 (TUG1) is an oncogenic lncRNA overexpressed in PCa. This exosomal lncRNA has been reported to promote PCa migration, invasion and Epithelial-Mesenchymal Transition (EMT). However, TUG1 PCa prognostic mechanisms remain to be elucidated. This study aimed to profile differentially expressed lncRNAs in PCa high-grade tumor cells (PC-3) cells compared to low-grade PCa tumor cells (LNCaP). This was achieved by using a 384-well plate of PCa lncRNA gene panel. A human lncRNA database, LncSEA and other bioinformatics tools were used for annotation and enrichment analysis. RT-qPCR was used to confirm the gene array data. Up or down-regulation of ±2 and p <0.05 were considered significant. Forty two (42%) percent and 14% of lncRNAs were shown to be up and downregulated, respectively. Notably, TUG1 was shown to be upregulated in PC-3 cells from PCR array and RT-qPCR results. Bioinformatics analysis revealed that TUG1 is involved in several cancer hallmarks including apoptosis evasion, migration, invasion and EMT. Furthermore, lncRNA/miRNA complexes regulate a series of oncogenic signaling pathways and this study demonstrated that TUG1 sponges the let-7 miRNA family members (a highly conserved tumor suppressor miRNA family) and promotes PCa progression. Precise mechanisms of TUG1/let-7 axis in PCa prognosis need to be largely elucidated as this may hold potential to understanding lncRNA/miRNA-mediated PCa progression and thus be targeted for novel therapeutics. Citation Format: Rahaba Makgotso Marima, Mandisa Mbeje, Jeyalakshmi Kandhavelu, Clement Penny, Zodwa Dlamini. TUG1 exosomal lncRNA sponges let-7 miRNA family members and advances prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2988.

Heterogeneous ERBB gene pathways, their targeted treatment and possible molecular mechanisms of resistance in metastatic gallbladder cancer

BackgroundERBB amplifications and mutations are known in metastatic gallbladder cancer (GBC). We conducted a prospective study on targeted therapy based on comprehensive genomic profiling (CGP). We report molecular pathways of ERBB gene and outcomes and explored the molecular mechanism of resistance. MethodsCGP was done for all consecutive GBC patients aged >18 years. Foundation medicines CDx and TarGT Absolute were used for analysis. Patients were enrolled from Jan 2017 till Dec 2022. Patient recruitment was done after ethics committee approval. Trastuzumab and/ or lapatinib were used as targeted therapy. ResultsTwenty-six patients out of 60 had ERBB1-4 gene alteration (amplification and/or mutation) that resulted in activation of PI3K/AKT/MTOR and RAS/RAF/MEK pathways. ERBB amplification (16%) was the most common genetic aberration. Mutations in TP53, RB1, CDKs, and cyclins lead to dysregulation of cell cycle and evasion of apoptosis. A total of 50% of ERBB2-positive patients carry CDK12 amplifications. The intrinsic resistance to anti-ERBB2 therapy was primarily due to downstream activation in ERBB pathway (PIK3CA) and its crosstalk with cell cycle pathway (TP53 and CDK12), JAK/STAT, VEGF, CTNNB1, and ARID1A that are known to drive MAPK/ERK signaling. Mesenchymal epithelial transition amplification or activating mutations is mechanism of resistance to anti-ERBB2 therapy. Kinase/Juxta membrane domain mutations in ERBB family proteins are also one of the potential mechanisms of resistance. ConclusionGBC is enriched with ERBB gene aberrations. Targeted therapy of ERBB pathway has shown encouraging responses. CDK12 gene amplification is a possible mechanism of resistance identified.

Apoptosis and Paraptosis Induced by Disulfiram-Loaded Ca2+/Cu2+ Dual-Ions Nano Trap for Breast Cancer Treatment.

Regarded as one of the hallmarks of tumorigenesis and tumor progression, the evasion of apoptotic cell death would also account for treatment resistance or failure during cancer therapy. In this study, a Ca2+/Cu2+ dual-ion "nano trap" to effectively avoid cell apoptosis evasion by synchronously inducing paraptosis together with apoptosis was successfully designed and fabricated for breast cancer treatment. In brief, disulfiram (DSF)-loaded amorphous calcium carbonate nanoparticles (NPs) were fabricated via a gas diffusion method. Further on, the Cu2+-tannic acid metal phenolic network was embedded onto the NPs surface by self-assembling, followed by mDSPE-PEG/lipid capping to form the DSF-loaded Ca2+/Cu2+ dual-ions "nano trap". The as-prepared nanotrap would undergo acid-triggered biodegradation upon being endocytosed by tumor cells within the lysosome for Ca2+, Cu2+, and DSF releasing simultaneously. The released Ca2+ could cause mitochondrial calcium overload and lead to hydrogen peroxide (H2O2) overexpression. Meanwhile, Ca2+/reactive oxygen species-associated mitochondrial dysfunction would lead to paraptosis cell death. Most importantly, cell paraptosis could be further induced and strengthened by the toxic dithiocarbamate (DTC)-copper complexes formed by the Cu2+ combined with the DTC, the metabolic products of DSF. Additionally, the released Cu2+ will be reduced by intracellular glutathione to generate Cu+, which can catalyze the H2O2 to produce a toxic hydroxyl radical by a Cu+-mediated Fenton-like reaction for inducing cell apoptosis. Both in vitro cellular assays and in vivo antitumor evaluations confirmed the cancer therapeutic efficiency by the dual ion nano trap. This study can broaden the cognition scope of dual-ion-mediated paraptosis together with apoptosis via a multifunctional nanoplatform.

Role of Cyclins and Cytoskeletal Proteins in Endometriosis: Insights into Pathophysiology.

Endometriosis is a gynecological condition where endometrium-like tissue grows outside the uterus, posing challenges in understanding and treatment. This article delves into the deep cellular and molecular processes underlying endometriosis, with a focus on the crucial roles played by cyclins and cytoskeletal proteins in its pathogenesis, particularly in the context of Epithelial-Mesenchymal Transition (EMT). The investigation begins by examining the activities of cyclins, elucidating their diverse biological roles such as cell cycle control, proliferation, evasion of apoptosis, and angiogenesis among ectopic endometrial cells. A comprehensive analysis of cytoskeletal proteins follows, emphasizing their fundamental biological roles and their specific significance to endometriotic cell features. This review sheds light on the interconnected pathways through which cyclins and cytoskeletal proteins converge, contributing to the genesis and progression of endometriosis. Understanding these molecular complexities not only provides insight into the underlying causes of the disease but also holds promise for the development of specific therapeutic approaches, ushering in a new era in the management of this devastating disorder.

CCN3, POSTN, and PTHLH as potential key regulators of genomic integrity and cellular survival in iPSCs.

Reprogramming human somatic cells into a pluripotent state, achieved through the activation of well-defined transcriptional factors known as OSKM factors, offers significant potential for regenerative medicine. While OSKM factors are a robust reprogramming method, efficiency remains a challenge, with only a fraction of cells undergoing successful reprogramming. To address this, we explored genes related to genomic integrity and cellular survival, focusing on iPSCs (A53T-PD1) that displayed enhanced colony stability. Our investigation had revealed three candidate genes CCN3, POSTN, and PTHLH that exhibited differential expression levels and potential roles in iPSC stability. Subsequent analyses identified various protein interactions for these candidate genes. POSTN, significantly upregulated in A53T-PD1 iPSC line, showed interactions with extracellular matrix components and potential involvement in Wnt signaling. CCN3, also highly upregulated, demonstrated interactions with TP53, CDKN1A, and factors related to apoptosis and proliferation. PTHLH, while upregulated, exhibited interactions with CDK2 and genes involved in cell cycle regulation. RT-qPCR validation confirmed elevated CCN3 and PTHLH expression in A53T-PD1 iPSCs, aligning with RNA-seq findings. These genes' roles in preserving pluripotency and cellular stability require further exploration. In conclusion, we identified CCN3, POSTN, and PTHLH as potential contributors to genomic integrity and pluripotency maintenance in iPSCs. Their roles in DNA repair, apoptosis evasion, and signaling pathways could offer valuable insights for enhancing reprogramming efficiency and sustaining pluripotency. Further investigations are essential to unravel the mechanisms underlying their actions.

Development of Potent Mcl-1 Inhibitors: Structural Investigations on Macrocycles Originating from a DNA-Encoded Chemical Library Screen.

Evasion of apoptosis is critical for the development and growth of tumors. The pro-survival protein myeloid cell leukemia 1 (Mcl-1) is an antiapoptotic member of the Bcl-2 family, associated with tumor aggressiveness, poor survival, and drug resistance. Development of Mcl-1 inhibitors implies blocking of protein-protein interactions, generally requiring a lengthy optimization process of large, complex molecules. Herein, we describe the use of DNA-encoded chemical library synthesis and screening to directly generate complex, yet conformationally privileged macrocyclic hits that serve as Mcl-1 inhibitors. By applying a conceptual combination of conformational analysis and structure-based design in combination with a robust synthetic platform allowing rapid analoging, we optimized in vitro potency of a lead series into the low nanomolar regime. Additionally, we demonstrate fine-tuning of the physicochemical properties of the macrocyclic compounds, resulting in the identification of lead candidates 57/59 with a balanced profile, which are suitable for future development toward therapeutic use.

Alternative translation contributes to the generation of a cytoplasmic subpopulation of the Junín virus nucleoprotein that inhibits caspase activation and innate immunity.

The highly pathogenic arenavirus, Junín virus (JUNV), expresses three truncated alternative isoforms of its nucleoprotein (NP), i.e., NP53kD, NP47kD, and NP40kD. While both NP47kD and NP40kD have been previously shown to be products of caspase cleavage, here, we show that expression of the third isoform NP53kD is due to alternative in-frame translation from M80. Based on this information, we were able to generate recombinant JUNVs lacking each of these isoforms. Infection with these mutants revealed that, while all three isoforms contribute to the efficient control of caspase activation, NP40kD plays the predominant role. In contrast to full-length NP (i.e., NP65kD), which is localized to inclusion bodies, where viral RNA synthesis takes place, the loss of portions of the N-terminal coiled-coil region in these isoforms leads to a diffuse cytoplasmic distribution and a loss of function in viral RNA synthesis. Nonetheless, NP53kD, NP47kD, and NP40kD all retain robust interferon antagonistic and 3'-5' exonuclease activities. We suggest that the altered localization of these NP isoforms allows them to be more efficiently targeted by activated caspases for cleavage as decoy substrates, and to be better positioned to degrade viral double-stranded (ds)RNA species that accumulate in the cytoplasm during virus infection and/or interact with cytosolic RNA sensors, thereby limiting dsRNA-mediated innate immune responses. Taken together, this work provides insight into the mechanism by which JUNV leverages apoptosis during infection to generate biologically distinct pools of NP and contributes to our understanding of the expression and biological relevance of alternative protein isoforms during virus infection.IMPORTANCEA limited coding capacity means that RNA viruses need strategies to diversify their proteome. The nucleoprotein (NP) of the highly pathogenic arenavirus Junín virus (JUNV) produces three N-terminally truncated isoforms: two (NP47kD and NP40kD) are known to be produced by caspase cleavage, while, here, we show that NP53kD is produced by alternative translation initiation. Recombinant JUNVs lacking individual NP isoforms revealed that all three isoforms contribute to inhibiting caspase activation during infection, but cleavage to generate NP40kD makes the biggest contribution. Importantly, all three isoforms retain their ability to digest double-stranded (ds)RNA and inhibit interferon promoter activation but have a diffuse cytoplasmic distribution. Given the cytoplasmic localization of both aberrant viral dsRNAs, as well as dsRNA sensors and many other cellular components of innate immune activation pathways, we suggest that the generation of NP isoforms not only contributes to evasion of apoptosis but also robust control of the antiviral response.

Integrin-associated transcriptional characteristics of circulating tumor cells in breast cancer patients.

Integrins enable cell communication with the basal membrane and extracellular matrix, activating signaling pathways and facilitating intracellular changes. Integrins in circulating tumor cells (CTCs) play a significant role in apoptosis evasion and anchor-independent survival. However, the link between CTCs expressing different integrin subunits, their transcriptional profile and, therefore, their functional activity with respect to metastatic potential remains unclear. Single-cell RNA sequencing of CD45-negative cell fraction of breast cancer patients was performed. All CTCs were divided into nine groups according to their integrin profile. СTCs without the gene expression of integrins or with the expression of non-complementary α and β subunits that cannot form heterodimers prevailed. Only about 15% of CTCs expressed integrin subunits which can form heterodimers. The transcriptional profile of CTCs appeared to be associated with the spectrum of expressed integrins. The lowest potential activity was observed in CTCs without integrin expression, while the highest frequency of expression of tumor progression-related genes, namely genes of stemness, epithelial-mesenchymal transition (EMT), invasion, proinflammatory chemokines and cytokines as well as laminin subunits, were observed in CTCs co-expressing ITGA6 and ITGB4. Validation on the protein level revealed that the median of integrin β4+ CTCs was higher in patients with more aggressive molecular subtypes as well as in metastatic breast cancer patients. One can expect that CTCs with ITGA6 and ITGB4 expression will have pronounced metastatic potencies manifesting in expression of EMT and stemness-related genes, as well as potential ability to produce chemokine/proinflammatory cytokines and laminins.

Immunofluorescence-Verified Sphingolipid Signatures Indicate Improved Prognosis in Liver Cancer Patients.

Background: Hepatocellular carcinoma (HCC) is a highly heterogeneous malignancy, with its pathogenesis involving a complex interplay of molecular mechanisms, including cell cycle dysregulation, evasion of apoptosis, enhanced angiogenesis, and aberrant immune responses. Precision medicine approaches that target specific molecular subtypes through multi-omics integration hold promise for improving patient survival. Among the various molecular players, sphingolipids have emerged as pivotal regulators of tumor growth and apoptosis, positioning them as key targets in the search for novel anticancer therapies. Methods: To identify critical genes involved in sphingolipid metabolism (SM), we employed the AUCell algorithm and correlation analysis in conjunction with scRNA-seq data. A robust prognostic risk model was developed using Cox proportional hazards and Lasso regression, and its predictive performance was validated using an independent cohort from the International Cancer Genome Consortium (ICGC). The model's evaluation also incorporated analyses of the tumor microenvironment (TME), immunotherapy responses, mutational landscape, and pathway enrichment across different risk strata. Finally, we conducted multiplex immunofluorescence assays to investigate the functional role of ZC3HAV1 in HCC. Results: Our analysis yielded a 9-gene signature risk model with strong prognostic capabilities, effectively stratifying HCC patients into high- and low-risk groups, with significant differences in survival outcomes. Notably, the model revealed distinct variations in the immune microenvironment and responsiveness to immunotherapy between the risk groups. Further experimental validation identified ZC3HAV1 as a key gene, with multiplex immunofluorescence suggesting its involvement in promoting malignant progression in HCC through modulation of the epithelial-mesenchymal transition (EMT). Conclusion: This sphingolipid metabolism-based prognostic model is not only predictive of survival in HCC but also indicative of immunotherapy efficacy in certain patient subsets. Our findings underscore the crucial role of sphingolipid metabolism in shaping the immune microenvironment, offering new avenues for targeted therapeutic interventions.

Drug-Resistant Epithelial Ovarian Cancer: Current and Future Perspectives.

Epithelial ovarian cancer (EOC) is a complex disease with diverse histological subtypes, which, based on the aggressiveness and course of disease progression, have recently been broadly grouped into type I (low-grade serous, endometrioid, clear cell, and mucinous) and type II (high-grade serous, high-grade endometrioid, and undifferentiated carcinomas) categories. Despite substantial differences in pathogenesis, genetics, prognosis, and treatment response, clinical diagnosis and management of EOC remain similar across the subtypes. Debulking surgery combined with platinum-taxol-based chemotherapy serves as the initial treatment for High Grade Serous Ovarian Carcinoma (HGSOC), the most prevalent one, and for other subtypes, but most patients exhibit intrinsic or acquired resistance and recur in short duration. Targeted therapies, such as anti-angiogenics (e.g., bevacizumab) and PARP inhibitors (for BRCA-mutated cancers), offer some success, but therapy resistance, through various mechanisms, poses a significant challenge. This comprehensive chapter delves into emerging strategies to address these challenges, highlighting factors like aberrant miRNAs, metabolism, apoptosis evasion, cancer stem cells, and autophagy, which play pivotal roles in mediating resistance and disease relapse in EOC. Beyond standard treatments, the focus of this study extends to alternate targeted agents, including immunotherapies like checkpoint inhibitors, CAR T cells, and vaccines, as well as inhibitors targeting key oncogenic pathways in EOC. Additionally, this chapter covers disease classification, diagnosis, resistance pathways, standard treatments, and clinical data on various emerging approaches, and advocates for a nuanced and personalized approach tailored to individual subtypes and resistance mechanisms, aiming to enhance therapeutic outcomes across the spectrum of EOC subtypes.

Polyporus ulleungus mycelia cultured in MEB medium produce metabolites with anticancer property.

Cancer cells are characterized by apoptosis evasion and uncontrolled cell cycle progression. To combat these characteristics, efforts have been made to find novel natural-source anticancer compounds. The aim of this work is to find new anticancer compounds in Polyporus ulleungus (P. ulleungus) mycelial culture extracts. P. ulleungus mycelium was cultured on four individual media (DYB, MEB, MYB, and PDB) and four extracts were generated from the mycelium culture media. Extracts of P. ulleungus mycelium cultured in MEB medium (pu-MEB) significantly reduced cancer cell growth by triggering apoptosis and S phase arrest. Furthermore, the anticancer effects of pu-MEB were not confined to one type of cancer. Taken together, our results confirmed that P. ulleungus mycelia cultured in MEB medium produce metabolites that exhibit anticancer properties. Development of an optimal medium for P. ulleungus mycelium through optimization of medium components will enable P. ulleungus mycelium to produce metabolites with more anticancer efficacy.

The accumulation of sphingosine kinase 2 disrupts the DNA damage response and promotes resistance to genotoxic agents

There is a known correlation between cancer and changes in sphingolipids, specifically the production of sphingosine-1-phosphate (S1P) by sphingosine kinases 1 and 2 (SPHK1/SPHK2). However, a potential relationship between bioactive lipid molecules, SPHK, and the response to DNA damage is unknown. We aimed to evaluate the response of oral keratinocytes and head and neck cancer cell lines with SPHK2/S1P alterations to DNA damage. This assessment is intended to establish a link between these alterations and tumorigenesis as well as resistance to therapy. SPHK2 overexpression in oral squamous cells promoted evasion of apoptosis and cell cycle control, which increased the resistance to genotoxic agents (chemical and physical). Cells that have SPHK2 overexpression are more prone to DNA damage, which allows those damaged cells to survive and multiply. This is associated with a decrease in overall DNA methylation. These discoveries help to clarify the connection between SPHK2 and the response to DNA damage, as well as its capacity to aid in the resistance against genotoxic agents, including those used in cancer treatment.

Ursolic Acid’s Alluring Journey: One Triterpenoid vs. Cancer Hallmarks

Cancer is a multifactorial disease characterized by various hallmarks, including uncontrolled cell growth, evasion of apoptosis, sustained angiogenesis, tissue invasion, and metastasis, among others. Traditional cancer therapies often target specific hallmarks, leading to limited efficacy and the development of resistance. Thus, there is a growing need for alternative strategies that can address multiple hallmarks concomitantly. Ursolic acid (UA), a naturally occurring pentacyclic triterpenoid, has recently emerged as a promising candidate for multitargeted cancer therapy. This review aims to summarize the current knowledge on the anticancer properties of UA, focusing on its ability to modulate various cancer hallmarks. The literature reveals that UA exhibits potent anticancer effects through diverse mechanisms, including the inhibition of cell proliferation, induction of apoptosis, suppression of angiogenesis, inhibition of metastasis, and modulation of the tumor microenvironment. Additionally, UA has demonstrated promising activity against different cancer types (e.g., breast, lung, prostate, colon, and liver) by targeting various cancer hallmarks. This review discusses the molecular targets and signaling pathways involved in the anticancer effects of UA. Notably, UA has been found to modulate key signaling pathways, such as PI3K/Akt, MAPK/ERK, NF-κB, and Wnt/β-catenin, which play crucial roles in cancer development and progression. Moreover, the ability of UA to destroy cancer cells through various mechanisms (e.g., apoptosis, autophagy, inhibiting cell growth, dysregulating cancer cell metabolism, etc.) contributes to its multitargeted effects on cancer hallmarks. Despite promising anticancer effects, this review acknowledges hurdles related to UA’s low bioavailability, emphasizing the need for enhanced therapeutic strategies.