Anti-apoptotic protein BCL-XL as a therapeutic vulnerability in gastric cancer

BACKGROUND

New therapeutic targets are needed to improve the outcomes for gastric cancer (GC) patients with advanced disease. Evasion of programmed cell death (apoptosis) is a hallmark of cancer cells and direct induction of apoptosis by targeting the pro-survival BCL2 family proteins represents a promising therapeutic strategy for cancer treatment. Therefore, understanding the molecular mechanisms underpinning cancer cell survival could provide a molecular basis for potential therapeutic interventions.

METHOD

Here we explored the role of BCL2L1 and the encoded anti-apoptotic BCL-XL in GC. Using Droplet Digital PCR (ddPCR) technology to investigate the DNA amplification of BCL2L1 in GC samples and GC cell lines, the sensitivity of GC cell lines to selective BCL-XL inhibitors A1155463 and A1331852, pan-inhibitor ABT-263, and VHL-based PROTAC-BCL-XL was analyzed using (CellTiter-Glo) CTG assay in vitro. Western Blot (WB) was used to detect the protein expression of BCL2 family members in GC cell lines and the manner in which PROTAC-BCL-XL kills GC cells. Co-immunoprecipitation (Co-IP) was used to investigate the mechanism of A1331852 and ABT-263 kills GC cell lines. DDPCR, WB, and real-time PCR (RTPCR) were used to investigate the correlation between DNA, RNA, protein levels, and drug activity.

RESULTS

The functional assay showed that a subset of GC cell lines relies on BCL-XL for survival. In gastric cancer cell lines, BCL-XL inhibitors A1155463 and A1331852 are more sensitive than the pan BCL2 family inhibitor ABT-263, indicating that ABT-263 is not an optimal inhibitor of BCL-XL. VHL-based PROTAC-BCL-XL DT2216 appears to be active in GC cells. DT2216 induces apoptosis of gastric cancer cells in a time- and dose-dependent manner through the proteasome pathway. Statistical analysis showed that the BCL-XL protein level predicts the response of GC cells to BCL-XL targeting therapy and BCL2L1 gene CNVs do not reliably predict BCL-XL expression.

CONCLUSION

We identified BCL-XL as a promising therapeutic target in a subset of GC cases with high levels of BCL-XL protein expression. Functionally, we demonstrated that both selective BCL-XL inhibitors and VHL-based PROTAC BCL-XL can potently kill GC cells that are reliant on BCL-XL for survival. However, we found that BCL2L1 copy number variations (CNVs) cannot reliably predict BCL-XL expression, but the BCL-XL protein level serves as a useful biomarker for predicting the sensitivity of GC cells to BCL-XL-targeting compounds. Taken together, our study pinpointed BCL-XL as potential druggable target for specific subsets of GC.

Tfl deletion induces extraordinary Cxcl13 secretion and cachexia in VavP-Bcl2 transgenic mice

STATEMENT OF SIGNIFICANCE

Loss of TFL, found in several types of lymphoma, induces excessive CXCL13 secretion through RNA dysregulation contributing to body weight loss and early death in lymphoma model mice. Follicular lymphoma (FL) is associated with overexpressed BCL-2 and other genetic aberrations, including 6q-. We identified a novel gene on 6q25, "Transformed follicular lymphoma (TFL)," from a transformed FL. TFL regulates several cytokines via mRNA degradation, which has been suggested to underlie resolving inflammation. Fluorescence in situ hybridization revealed a deletion of TFL occurred in 13.6% of various B-cell lymphoma samples. We developed VavP-bcl2 transgenic, TFL deficit mice (Bcl2-Tg/Tfl -/-) to seek how TFL affects disease progression in this lymphoma model. While Bcl2-Tg mice developed lymphadenopathy and died around 50 weeks, Bcl2-Tg/Tfl -/- mice lost body weight around 30 weeks and died about 20 weeks earlier than Bcl2-Tg mice. Furthermore, we found a unique B220-IgM+ cell population in the bone marrow of Bcl2-Tg mice. cDNA array in this population revealed that Cxcl13 mRNA in Bcl2-Tg/Tfl -/- mice expressed significantly higher than Bcl2-Tg mice. In addition, bone marrow extracellular fluid and serum showed an extremely high Cxcl13 concentration in Bcl2-Tg/Tfl -/- mice. Among bone marrow cells, the B220-IgM+ fraction was the main producer of Cxcl13 in culture. A reporter assay demonstrated TFL regulates CXCL-13 via induction of 3'UTR mRNA degradation in B lineage cells. These data suggest Tfl regulates Cxcl13 in B220-IgM+ cells in the bone marrow, and a very high concentration of serum Cxcl13 arising from these cells may contribute to early death in lymphoma-bearing mice. Since several reports have suggested the association of CXCL13 expression with lymphoma, these findings provide new insights into cytokine regulation via TFL in lymphoma.

Inhibition of miR-143-3p alleviates myocardial ischemia reperfusion injury via limiting mitochondria-mediated apoptosis

MicroRNA (miR)-143-3p is a potential regulatory molecule in myocardial ischemia/reperfusion injury (MI/RI), wherein its expression and pathological effects remains controversial. Thus, a mouse MI/RI and cell hypoxia/reoxygenation (H/R) models were built for clarifying the miR-143-3p's role in MI/RI. Following myocardial ischemia for 30 min, mice underwent reperfusion for 3, 6, 12 and 24 h. It was found miR-143-3p increased in the ischemic heart tissue over time after reperfusion. Cardiomyocytes transfected with miR-143-3p were more susceptible to apoptosis. Mechanistically, miR-143-3p targeted B cell lymphoma 2 (bcl-2). And miR-143-3p inhibition reduced cardiomyocytes apoptosis upon H/R, whereas it was reversed by a specific bcl-2 inhibitor ABT-737. Of note, miR-143-3p inhibition upregulated bcl-2 with better mitochondrial membrane potential (Δψm), reduced cytoplasmic cytochrome c (cyto-c) and caspase proteins, and minimized infarction area in mice upon I/R. Collectively, inhibition of miR-143-3p might alleviate MI/RI via targeting bcl-2 to limit mitochondria-mediated apoptosis. To our knowledge, this study further clarifies the miR-143-3p's pathological role in the early stages of MI/RI, and inhibiting miR-143-3p could be an effective treatment for ischemic myocardial disease.

Relationship between BCL2 mutations and follicular lymphoma outcome in the chemoimmunotherapy era

How to identify follicular lymphoma (FL) patients with low disease burden but high risk for early progression is unclear. Building on a prior study demonstrating the early transformation of FLs with high variant allele frequency (VAF) BCL2 mutations at activation-induced cytidine deaminase (AICDA) sites, we examined 11 AICDA mutational targets, including BCL2, BCL6, PAX5, PIM1, RHOH, SOCS, and MYC, in 199 newly diagnosed grade 1 and 2 FLs. BCL2 mutations with VAF ≥20% occurred in 52% of cases. Among 97 FL patients who did not initially receive rituximab-containing therapy, nonsynonymous BCL2 mutations at VAF ≥20% were associated with increased transformation risk (HR 3.01, 95% CI 1.04-8.78, p = 0.043) and a trend toward shorter event-free survival (EFS, median 20 months with mutations versus 54 months without, p = 0.052). Other sequenced genes were less frequently mutated and did not increase the prognostic value of the panel. Across the entire population, nonsynonymous BCL2 mutations at VAF ≥20% were associated with decreased EFS (HR 1.55, 95% CI 1.02-2.35, p = 0.043 after correction for FLIPI and treatment) and decreased overall survival after median 14-year follow-up (HR 1.82, 95% CI 1.05-3.17, p = 0.034). Thus, high VAF nonsynonymous BCL2 mutations remain prognostic even in the chemoimmunotherapy era.

Patterns of Oncogene Coexpression at Single-Cell Resolution Influence Survival in Lymphoma

Cancers often overexpress multiple clinically relevant oncogenes, but it is not known if combinations of oncogenes in cellular subpopulations within a cancer influence clinical outcomes. Using quantitative multispectral imaging of the prognostically relevant oncogenes MYC, BCL2, and BCL6 in diffuse large B-cell lymphoma (DLBCL), we show that the percentage of cells with a unique combination MYC+BCL2+BCL6- (M+2+6-) consistently predicts survival across four independent cohorts (n = 449), an effect not observed with other combinations including M+2+6+. We show that the M+2+6- percentage can be mathematically derived from quantitative measurements of the individual oncogenes and correlates with survival in IHC (n = 316) and gene expression (n = 2,521) datasets. Comparative bulk/single-cell transcriptomic analyses of DLBCL samples and MYC/BCL2/BCL6-transformed primary B cells identify molecular features, including cyclin D2 and PI3K/AKT as candidate regulators of M+2+6- unfavorable biology. Similar analyses evaluating oncogenic combinations at single-cell resolution in other cancers may facilitate an understanding of cancer evolution and therapy resistance.

SIGNIFICANCE

Using single-cell-resolved multiplexed imaging, we show that selected subpopulations of cells expressing specific combinations of oncogenes influence clinical outcomes in lymphoma. We describe a probabilistic metric for the estimation of cellular oncogenic coexpression from IHC or bulk transcriptomes, with possible implications for prognostication and therapeutic target discovery in cancer. This article is highlighted in the In This Issue feature, p. 1027.

A novel tumour enhancer function of Insulin-like growth factor II mRNA-binding protein 3 in colorectal cancer

CRC cells evolve a variety of strategies to limit or circumvent apoptosis cell death. RNA binding proteins (RBPs) regulate many of the molecular mechanisms that underlie the development of cancer. The insulin-like growth factor II mRNA-binding proteins (IMP) family are oncofoetal RBPs, consisting of IMP1, IMP2 and IMP3, which have an important role in RNA metabolism. IMP3 is highly expressed in colorectal cancer (CRC) tissue, where its expression often correlates with poor prognosis. However, the role of IMP3 in CRC is not fully understood. IMP3 expression was analysed using a public database and by Western blotting and immunohistochemistry in human colon samples derived from patients with sporadic CRC and healthy subjects. To address whether IMP3 controls cancer cell survival, we analysed cell death pathways in in vitro and in vivo experiments after IMP3 downregulation by siRNA or an antisense oligonucleotide. IMP3 was highly expressed in CRC samples compared to normal control tissues. The knockdown of IMP3 enhanced a caspase-independent cell death in CRC cell lines. Furthermore, the treatment of CRC cells with IMP3 siRNA did not alter the expression of GSDMD, GPX-4 and the activated form of RIP3, three key molecules that govern pyroptosis, ferroptosis and necroptosis, respectively. Abrogation of IMP3 in CRC significantly reduced Bcl-2 and Bcl-xL mRNA and was associated with an altered mitochondrial membrane potential that allowed the nuclear migration of the apoptosis-inducing factor (AIF). Moreover, specific immunoprecipitation experiments on CRC human cell lines indicated that IMP3 binds Bcl-2 and Bcl-xL mRNA, suggesting that IMP3 acts as a regulator of the intrinsic apoptotic pathway through the surveillance of anti-apoptotic Bcl mRNA metabolism. Finally, we showed that IMP3 block inhibited the growth of CRC cell lines in vivo after transplantation into immunodeficient mice. Altogether, these data support a novel role for IMP3 in controlling the intrinsic caspase-independent apoptotic pathway in CRC.

Tumor-specific activated nano-domino-CRISPR to amplify intrinsic oxidative and activate endogenous apoptosis for spatiotemporally specific therapy

As a non-invasive modality with unique spatiotemporal selectivity, photodynamic therapy (PDT) is emerging as a candidate in cancer treatment. Nevertheless, intrinsic anti-oxidative stress factors represented by the up-regulated B cell lymphoma/leukemia-2 (Bcl-2) and the attenuated-PDT activity along the light path are still the major concerns, therefore exploring the PDT-based synergistic and augmented strategies is challenging but imperative. Here, a tumor-specific activated nano-domino-CRISPR (TAN) is fabricated and coloaded with chlorins e6 (Ce6) and CRISPR/Cas9 plasmid targeting Bcl-2 gene to amplify intrinsic oxidative and activate endogenous apoptosis for spatiotemporally specific therapy. Inert TAN acting as the first domino is activated in enzyme-abundant intracellular environment to strip the shell. The activated TAN pushes the subsequent dominos, encompassing orderly efficient lysosomal escape, gene delivery, precise disruption of Bcl-2 protein and PDT effect induced by the shell containing Ce6 with light to trigger further domino effects. For tumor cells located superficial sites, down-regulated Bcl-2 reduces cellular GSH content and potentiates oxidative stress of PDT. Cells located deep sites are triggered endogenous apoptosis by disruption of Bcl-2. The high anti-tumor efficacy of TAN is demonstrated both in vitro and in vivo. Overall, our work offers a valuable emerging approach for conquering the therapeutical deficiency of PDT.

Sequence analyses of relapsed or refractory diffuse large B-cell lymphomas unravel three genetic subgroups of patients and the GNA13 mutant as poor prognostic biomarker, results of LNH-EP1 study

Advances in molecular profiling of newly diagnosed diffuse large B-cell lymphoma (DLBCL) have recently refine genetic subgroups. Genetic subgroups remain undetermined at the time of relapse or refractory (RR) disease. This study aims to decipher genetic subgroups and search for prognostic molecular biomarkers in patients with RR-DLBCL. From 2015 to 2021, targeted next-generation sequencing analyses of germline-matched tumor samples and fresh tissue from RR-DLBCL patients were performed. Unsupervised clustering of somatic mutations was performed and correlations with patient outcome were sought. A number of 120 patients with RR-DLBCL were included in LNH-EP1 study and a molecular tumor landscape was successfully analyzed in 87% of patients (104/120 tumor samples). The median age was 67.5 years (range 27.4-87.4), median number of previous treatments was 2 (range 1-9). The most frequently mutated genes were TP53 (n = 53 mutations; 42% of samples), CREBBP (n = 39; 32%), BCL2 (n = 86; 31%), KMT2D (n = 39; 28%) and PIM1 (n = 54; 22%). Unsupervised clustering separated three genetic subgroups entitled BST (enriched in BCL2, SOCS1, and TNFRSF14 mutations); TKS (enriched in TP53, KMT2D, and STAT6 mutations); and PCM (enriched in PIM1, CD79B, and MYD88 mutations). Median overall survival (OS) was 11.0 (95% confidence interval [CI]: 8.1-12.6) months. OS was not significantly different between the three genetic subgroups. GNA13 mutant was significantly associated with an increased risk of death (hazard ratio: 6.6 [95% CI: 2.1-20.6]; p = .0011) and shorter OS (p = .0340). At the time of relapse or refractory disease, three genetic subgroups of DLBCL patients were delineated, which could help advance precision molecular medicine programs.

7-geranyloxycoumarin enhanced radiotherapy effects on human gastric adenocarcinoma cells

Background

Gastric adenocarcinoma (GA) is a serious malignancy with growing incidence and mortality rate worldwide. The objective of the present study was to determine whether 7-geranyloxycoumarin, a natural monoterpene coumarin, could induce anticancer effects, in single use and/or in combination with anticancer drugs and ionizing radiation, on GA cells.

Materials and Methods

7-geranyloxycoumarin was synthesized by a reaction between 7-hydroxycoumarin and transgeranyl bromide. MKN45 cells were treated with 7-geranyloxycoumarin, and the viability of cells was determined by resazurin. Apoptosis was then evaluated by flow cytometric analysis using annexin V and propidium iodide, and the expression of P53 and BCL2 was analyzed by quantitative polymerase chain reaction (qPCR). Combinatorial effects of 7-geranyloxycoumarin with 5-fluorouracil (5-FU), cisplatin (CDDP), and X radiation were also evaluated.

Results

Assessment of cell viability indicated that 7-geranyloxycoumarin induced its toxic effects in a time- and dose-dependent manner. This was confirmed by the detection of apoptotic cells, and qPCR results revealed a significant downregulation in BCL2 expression. Although combinatorial use of 7-geranyloxycoumarin + 5-FU or + CDDP did not improve cytotoxicity of anticancer drugs, significant increase in the effectiveness of applied radiations was detected upon pretreatment with 7-geranyloxycoumarin.

Conclusion

Our findings provide valuable insights into single and combinatorial effects of 7-geranyloxycoumarin on the GA cells.

[Alcohol extract of root and root bark of Toddalia asiatica alleviates CIA in rats through anti-inflammatory and proapoptotic effects]

This study aims to investigate the therapeutic effect of alcohol extract of root and root bark of Toddalia asiatica(TAAE) on collagen-induced arthritis(CIA) in rats through phosphatidylinoinosidine-3 kinase/protein kinase B(PI3K/Akt) signaling pathway. To be specific, CIA was induced in rats, and then the rats were treated(oral, daily) with TAAE and Tripterygium Glycoside Tablets(TGT), respectively. The swelling degree of the hind leg joints was scored weekly. After 35 days of administration, the histopathological changes were observed based on hematoxylin and eosin(HE) staining. Enzyme-linked immunosorbent assay(ELISA) was employed to detect the levels of cytokines [tumor necrosis factor-α(TNF-α), interleukin(IL)-6)]. Terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL) staining was performed to detect the apoptosis of synoviocytes in rats. Western blot was used to detect the expression levels of apoptosis-related proteins B-cell lymphoma 2(Bcl-2)-associated X(Bax), Bcl-2, and caspase-3 and pathway-related proteins phosphoinositide 3-kinase(PI3K), phosphorylated(p)-PI3K, protein kinase B(Akt), and p-Akt. RT-qPCR was conducted to examine the mRNA levels of Bax, Bcl-2, caspase-3, TNF-α, IL-6, and IL-1β and pathway-related proteins PI3K, p-PI3K, Akt, and p-Akt. TAAE can alleviate the joint swelling in CIA rats, reduce serum levels of inflammatory cytokines, improve synovial histopathological changes, promote apoptosis of synoviocytes, and inhibit synovial inflammation. In addition, RT-qPCR and Western blot results showed that TAAE up-regulated the level of Bax, down-regulated the level of Bcl-2, and activated caspase-3 to promote apoptosis in synoviocytes. TAAE effectively down-regulated the protein levels of p-PI3K and p-Akt. In this study, TAAE shows therapeutic effect on CIA in rats and reduces the inflammation. The mechanism is that it suppresses PI3K/Akt signaling pathway and promotes synoviocyte apoptosis. Overall, this study provides a new clue for the research on the anti-inflammatory mechanism of TAAE and lays a theoretical basis for the better clinical application of TAAE in the treatment of inflammatory and autoimmune diseases.

Apolipoprotein E2 inhibits mitochondrial apoptosis in pancreatic cancer cells through ERK1/2/CREB/BCL-2 signaling

BACKGROUND

Apolipoprotein E2 (ApoE2) is a pleiotropic protein that influences several aspects of cancer metabolism and development. Evading apoptosis is a vital factor for facilitating cancer cell growth. However, the role and mechanism of ApoE2 in regulating cell apoptosis of pancreatic cancer remain unclear.

METHODS

In this study, we firstly detected the mRNA and protein expressions of ApoE2 in PANC-1 and Capan-2 cells by real-time polymerase chain reaction and Western blotting. We then performed TUNEL and flow cytometric analyses to explore the role of recombinant human ApoE2, pCMV6-ApoE2 and siApoE2 in the apoptosis of PANC-1 and Capan-2 cells. Furthermore, we investigated the molecular mechanism through which ApoE2 affected apoptosis in PANC-1 cells using immunofluorescence, immunoprecipitation, Western blotting and co-immunoprecipitation analysis.

RESULTS

ApoE2 phosphorylated ERK1/2 and inhibited pancreatic cancer cell apoptosis. In addition, our data showed that ApoE2/ERK1/2 altered the expression and mitochondrial localization of BCL-2 via activating CREB. ApoE2/ERK1/2/CREB also increased the total BCL-2/BAX ratio, inhibited the opening of the mitochondrial permeability transition pore and the depolarization of mitochondrial transmembrane potential, blocked the leakage of cytochrome-c and the formation of the apoptosome, and consequently, suppressed mitochondrial apoptosis.

CONCLUSIONS

ApoE2 regulates the mitochondrial localization and expression of BCL-2 through the activation of the ERK1/2/CREB signaling cascade to evade the mitochondrial apoptosis of pancreatic cancer cells. ApoE2 may be a distinct prognostic marker and a potential therapeutic target for pancreatic cancer.

Erythroid/megakaryocytic differentiation confers BCL-XL dependency and venetoclax resistance in acute myeloid leukemia

Myeloid neoplasms with erythroid or megakaryocytic differentiation include pure erythroid leukemia, myelodysplastic syndrome with erythroid features, and acute megakaryoblastic leukemia (FAB M7) and are characterized by poor prognosis and limited treatment options. Here, we investigate the drug sensitivity landscape of these rare malignancies. We show that acute myeloid leukemia (AML) cells with erythroid or megakaryocytic differentiation depend on the antiapoptotic protein B-cell lymphoma (BCL)-XL, rather than BCL-2, using combined ex vivo drug sensitivity testing, genetic perturbation, and transcriptomic profiling. High-throughput screening of >500 compounds identified the BCL-XL-selective inhibitor A-1331852 and navitoclax as highly effective against erythroid/megakaryoblastic leukemia cell lines. In contrast, these AML subtypes were resistant to the BCL-2 inhibitor venetoclax, which is used clinically in the treatment of AML. Consistently, genome-scale CRISPR-Cas9 and RNAi screening data demonstrated the striking essentiality of BCL-XL-encoding BCL2L1 but not BCL2 or MCL1, for the survival of erythroid/megakaryoblastic leukemia cell lines. Single-cell and bulk transcriptomics of patient samples with erythroid and megakaryoblastic leukemias identified high BCL2L1 expression compared with other subtypes of AML and other hematological malignancies, where BCL2 and MCL1 were more prominent. BCL-XL inhibition effectively killed blasts in samples from patients with AML with erythroid or megakaryocytic differentiation ex vivo and reduced tumor burden in a mouse erythroleukemia xenograft model. Combining the BCL-XL inhibitor with the JAK inhibitor ruxolitinib showed synergistic and durable responses in cell lines. Our results suggest targeting BCL-XL as a potential therapy option in erythroid/megakaryoblastic leukemias and highlight an AML subgroup with potentially reduced sensitivity to venetoclax-based treatments.

Assessment of the Anticancer Effect of Chlorojanerin Isolated from Centaurothamnus maximus on A549 Lung Cancer Cells

The goal of this study was to assess the anticancer efficacy of chlorojanerin against various cancer cells. The effects of chlorojanerin on cell cytotoxicity, cell cycle arrest, and cell apoptosis were examined using MTT assay, propidium iodide staining, and FITC Annexin V assay. RT-PCR was employed to determine the expression levels of apoptosis-related genes. Furthermore, docking simulations were utilized to further elucidate the binding preferences of chlorojanerin with Bcl-2. According to MTT assay, chlorojanerin inhibited the proliferation of all tested cells in a dose-dependent manner with a promising effect against A549 lung cancer cells with an IC50 of 10 µM. Cell growth inhibition by chlorojanerin was linked with G2/M phase cell cycle arrest in A549 treated cells. Flow cytometry analysis indicated that the proliferation inhibition effect of chlorojanerin was associated with apoptosis induction in A549 cells. Remarkably, chlorojanerin altered the expression of many genes involved in apoptosis initiation. Moreover, we determined that chlorojanerin fit into the active site of Bcl-2 according to the molecular docking study. Collectively, our results demonstrate that chlorojanerin mediated an anticancer effect involving cell cycle arrest and apoptotic cell death and, therefore, could potentially serve as a therapeutic agent in lung cancer treatment.

Oviductal sperm storage in the Chinese pond turtle, Mauremys reevesii, depends on androgen-based promotion of the BCL 2 anti-apoptotic pathway

CONTEXT

Sperm storage is a complex and highly coordinated process that is regulated by a variety of factors. The BCL 2 protein family plays a key role in regulating apoptosis, and determines sperm survival.

AIMS

The objective of this study was to explore the correlation between sperm storage and the BCL 2 protein family in the oviduct of Mauremys reevesii.

METHODS

Hematoxylin-eosin (HE) staining, immunohistochemistry (IHC) and real-time quantitative polymerase chain reaction (RT-qPCR) techniques were used to investigate three parts of the reproductive tract (isthmus, uterus and vagina) of mated and unmated female M. reevesii.

KEY RESULTS

Hematoxylin-eosin staining revealed many sperm stored in the oviduct. IHC showed positive immunostaining for the BCL 2 and BAX proteins in epithelial ciliated and glandular cells. RT-qPCR indicated that the mRNA expressions of anti-apoptotic genes (BCL 2, MCL 1, BCL-W, BCL-XL) and the androgen receptor (AR) were significantly higher in mated turtles than unmated turtles. However, the expression of pro-apoptotic genes (BAX, BAD, BID and CASPASE 3) showed the opposite relationship.

CONCLUSIONS

These results suggest that sperm entering the oviduct can promote the synthesis of anti-apoptotic genes to protect themselves from various degradation factors.

IMPLICATIONS

These findings will help researchers understand the mechanisms of sperm storage.

Synthetic lethality of drug-induced polyploidy and BCL-2 inhibition in lymphoma

Spontaneous whole genome duplication and the adaptive mutations that disrupt genome integrity checkpoints are infrequent events in B cell lymphomas. This suggests that lymphomas might be vulnerable to therapeutics that acutely trigger genomic instability and polyploidy. Here, we report a therapeutic combination of inhibitors of the Polo-like kinase 4 and BCL-2 that trigger genomic instability and cell death in aggressive lymphomas. The synthetic lethality is selective for tumor cells and spares vital organs. Mechanistically, inhibitors of Polo-like kinase 4 impair centrosome duplication and cause genomic instability. The elimination of polyploid cells largely depends on the pro-apoptotic BAX protein. Consequently, the combination of drugs that induce polyploidy with the BCL-2 inhibitor Venetoclax is highly synergistic and safe against xenograft and PDX models. We show that B cell lymphomas are ill-equipped for acute, therapy-induced polyploidy and that BCL-2 inhibition further enhances the removal of polyploid lymphoma cells.

Landscape of BCL2 Resistance Mutations in a Real-World Cohort of Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia Treated with Venetoclax

The oral, highly selective Bcl2 inhibitor venetoclax has substantially improved the therapeutic landscape of chronic lymphocytic leukemia (CLL). Despite the remarkable response rates in patients with relapsed/refractory (R/R) disease, acquired resistance is the leading cause of treatment failure, with somatic BCL2 mutations being the predominant genetic drivers underpinning venetoclax resistance. To assess the correlation between disease progression and the most common BCL2 mutations G101V and D103Y, sensitive (10−4) screening for the most common BCL2 mutations G101V and D103Y was performed in 67 R/R CLL patients during venetoclax single-agent or venetoclax–rituximab combination therapy. With a median follow-up time of 23 months, BCL2 G101V and D103Y were detected in 10.4% (7/67) and 11.9% (8/67) of the cases, respectively, with four patients harboring both resistance mutations. Ten out of eleven patients carrying BCL2 G101V and/or D103Y experienced relapse during the follow-up period, representing 43.5% of the cases (10/23) showing clinical signs of disease progression. All BCL2 G101V or D103Y variants were detected in patients receiving venetoclax as a continuous single-agent treatment while these mutations were not observed during or after fixed-duration venetoclax therapy. Targeted ultra-deep sequencing of BCL2 uncovered three additional variants in four patient samples obtained at relapse, suggesting convergent evolution and implying a cooperating role of BCL2 mutations in driving venetoclax resistance. This cohort is the largest R/R CLL patient population reported to date in which BCL2 resistance mutations were investigated. Our study demonstrates the feasibility and clinical value of sensitive screening for BCL2 resistance mutations in R/R CLL.

Molecular characterization and expression analysis of B-cell lymphoma-2 in Trachinotus ovatus and its role in apoptotic process

Introduction

B-cell lymphoma-2 (Bcl-2) is the first identified member of the Bcl-2 family that performs an anti-apoptotic function in mammals. However, its role in teleosts is not fully understood. In this study, Bcl-2 of Trachinotus ovatus (TroBcl2) was cloned, and its role in apoptosis was investigated.

Methods

In this study, Bcl-2 of Trachinotus ovatus (TroBcl2) was cloned by PCR. Quantitative real-time PCR (qRT-PCR) was used to detect its mRNA expression level in healthy condition and after LPS stimulation. Subcellular localization was performed by transfecting the pTroBcl2-N3 plasmid into golden pompano snout (GPS) cells and observed under an inverted fluorescence microscope DMi8 and further verified by immunoblotting. In vivo overexpression and RNAi knockdown method were performed to evaluate the role of TroBcl2 in apoptosis. The anti-apoptotic activity of TroBcl2 was detected by flow cytometry. The effect of TroBcl2 on the mitochondrial membrane potential (MMP) was measured by an enhanced mitochondrial membrane potential assay kit with JC-1. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method was performed to evaluate the role of TroBcl2 in the DNA fragmentation. Immunoblotting was used to verify whether TroBcl2 inhibits the release of cytochrome c from mitochondria into the cytoplasm. The Caspase 3 and Caspase 9 Activity Assay Kits were used to investigate the effect of TroBcl2 on caspase 3 and caspase 9 activities. The effects of TroBcl2 on the expression of apoptosis-related and nuclear factor- κB (NF-κB) signaling pathway-related genes in vitro were evaluated by qRT-PCR and Enzyme linked immunosorbent assay (ELISA). Luciferase reporter assay was used to evaluate the activity in NF-κB signaling pathway.

Results and discussion

The full-length coding sequence of TroBcl2 contains 687 bp and encodes a protein containing 228 amino acids. Four conserved Bcl-2 homology (BH) domains and one invariant “NWGR” motif located in BH1 were identified in TroBcl2. In healthy T. ovatus, TroBcl2 was widely distributed in the eleven tested tissues, and higher expression levels were found in immune-related tissues, such as spleen and head kidney tissues. After stimulation with lipopolysaccharide (LPS), the expression of TroBcl2 in the head kidney, spleen, and liver was significantly upregulated. In addition, subcellular localization analysis revealed that TroBcl2 was localized in both the cytoplasm and nucleus. Functional experiments showed that TroBcl2 inhibited apoptosis, possibly by reducing mitochondrial membrane potential loss, decreasing DNA fragmentation, preventing cytochrome c release into cytoplasm, and reducing the caspase 3 and caspase 9 activations. Moreover, upon LPS stimulation, overexpression of TroBcl2 suppressed the activation of several apoptosis-related genes, such as BOK, caspase-9, caspase-7, caspase-3, cytochrome c, and p53. Furthermore, knockdown of TroBcl2 significantly increased the expression of those apoptosis-related genes. In addition, TroBcl2 overexpression or knockdown induced or inhibited, respectively, the transcription of NF-κB and regulated the expression of genes (such as NF-κB1 and c-Rel) in the NF-κB signaling pathway as well as the expression of the downstream inflammatory cytokine IL-1β. Overall, our study suggested that TroBcl2 performs its conserved anti-apoptotic function via the mitochondrial pathway and may serve as an anti-apoptotic regulator in T. ovatus.

Follicle Center Lymphoma (FCL) of the Lower Female Genital Tract (LFGT): A Novel Variant of Primary Cutaneous Follicle Center Lymphoma (PCFCL)

Primary cutaneous follicle center lymphoma has been distinguished from nodal follicular lymphoma (FL) based on genomic and clinical features. The nature of other extranodal FLs is not well defined. We report 15 cases of follicle center lymphoma involving the lower female genital tract. Cases were evaluated using an immunohistochemical panel for B-cell lymphoma, B-cell clonality, fluorescence in situ hybridization for BCL2 gene rearrangement, and next-generation sequencing. All patients had localized disease with no evidence of bone marrow involvement. Most cases (12/15, 80%) had a follicular pattern, at least focally. Large centrocytes were a prominent feature leading to concern for diffuse large B-cell lymphoma by referring pathologists. Neoplastic cells were positive for CD20 and BCL-6, while BCL-2 was positive in 2/15 (13%) cases. Fluorescence in situ hybridization for BCL2 gene rearrangement was negative in 10/11 (91%) cases. Next-generation sequencing performed in 10 cases revealed TNFRSF14 as the most frequently mutated gene in 6/10 (60%) cases. No case had CREBBP or KMT2D mutations as seen in nodal FL. None of the patients had progressive disease with durable complete remission achieved in 10/12 (83%) cases. The median follow-up period was 7.8 years (range: 0.2 to 20.5 y) with a 5-year overall survival of 100%. We conclude that follicle center lymphoma of the lower female genital tract is a novel variant of primary cutaneous follicle center lymphoma. Despite a frequent component of large cells, it is characterized by localized disease and low risk for dissemination. Awareness and recognition are important to distinguish these lesions from aggressive B-cell lymphomas.

Superparamagnetic Iron Oxide Nanoparticles Induce Apoptosis in HT-29 Cells by Stimulating Oxidative Stress and Damaging DNA

Nanoparticles have garnered considerable scientific attention in recent years due to their diagnostic and therapeutic applications in cancer. The purpose of this study was to determine the effect of superparamagnetic iron oxide nanoparticles (Fe₃O₄ MNPs) on the induction of apoptosis in human colorectal adenocarcinoma cell line (HT-29) cells. The purpose of this study was to elucidate the mechanisms of apoptosis induced by Fe₃O₄ MNPs following MTT assay and to determine the optimal dose of 2.5 g/mL for inducing apoptosis in HT-29 cells. In HT-29 cells, Fe₃O₄ MNPs increased reactive oxygen species (ROS), calcium ion (Ca²⁺), and DNA damage. Additionally, the Fe₃O₄ MNPs significantly increased caspase 3 and 9 expression and decreased Bcl-2 expression at the protein and mRNA levels when compared to the control group (P = 0.0001). Fe₃O₄ MNPs also induced apoptosis in cancer cells by increasing the level of (ROS) and intracellular Ca²⁺, followed by an increase in caspase 3 and 9 expression and a decrease in Bcl-2 expression and direct DNA damage. Fe₃O₄ MNPs are an appropriate choice for colon cancer treatment based on their cell toxicity and induction of apoptosis in HT29 cells.

Sini San ameliorates CCl4-induced liver fibrosis in mice by inhibiting AKT-mediated hepatocyte apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Sini San (SNS) is recorded in Zhang Zhongjing's "Treatise on Typhoids" and is used in the treatment of non-alcoholic fatty liver disease, hepatitis, and other liver diseases, with good efficacy in liver fibrosis. However, its anti-liver fibrosis mechanism remains unclear.

AIM OF THE STUDY

This study aimed to evaluate the ameliorative effect of SNS on carbon tetrachloride (CCl4)-induced liver fibrosis in mice and the underlying mechanisms.

MATERIALS AND METHODS

The active ingredients in the water extract of SNS were determined using high-performance liquid chromatography (HPLC). CCl₄-induced liver fibrosis mice were subsequently treated with different doses of SNS for 3 weeks, and AST, ALT, and T-BIL were detected in the serum. The pathological characteristics of the liver were observed using hematoxylin and eosin (H&E) and Masson's staining. Hepatocyte apoptosis was assessed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The proteins expression of PI3K, p-PI3K, AKT, p-AKT, FXR, caspase-8, Bax, and Bcl-2 was analyzed using western blotting and immunofluorescence. FXR mRNA expression was measured using quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR). Using network pharmacology and bioinformatics to search for active ingredients that regulate PI3K/AKT signaling in the SNS. The material basis for regulating PI3K/AKT signaling in SNS was searched using network pharmacology and bioinformatics. Based on the network pharmacology results, isorhamnetin or SNS-containing serum was added to HepG2 cells stimulated with TNF-α. The Cell Counting Kit (CCK)-8 assay was used to analyze cell viability and apoptosis of HepG2 cells was detected using flow cytometry.

RESULTS

SNS reduced serum levels of AST, ALT and T-BIL, down-regulated caspase-8 protein expression and the ratio of Bcl-2/Bax protein expression, and improved apoptosis in liver fibrosis mice. In addition, SNS downregulated the ratio of p-PI3K/PI3K and p-AKT/AKT protein expression and increased FXR expression. Network pharmacology studies showed that quercetin, kaempferol and isorhamnetin in SNS can bind to AKT. In vitro experiments showed that isorhamnetin inhibited HepG2 cell apoptosis, upregulated FXR expression and suppressed AKT activity, whereas AKT inhibitors blocked the effects of isorhamnetin. The effect of the SNS-containing serum was similar to that of isorhamnetin.

CONCLUSION

SNS ameliorated the progression of fibrosis and improved hepatocyte apoptosis in liver fibrosis mice. The anti-apoptotic mechanism was related to the inhibition of AKT-mediated down-regulation of FXR expression by its active ingredient, isorhamnetin.

Targeting RNA Splicing Overcomes Leukemia Resistance to BCL2 Inhibition

Inactivation of RNA splicing factors enhances BCL2 inhibition in acute myeloid leukemia (AML).

High caspase 3 and vulnerability to dual BCL2 family inhibition define ETO2::GLIS2 pediatric leukemia

Pediatric acute myeloid leukemia expressing the ETO2::GLIS2 fusion oncogene is associated with dismal prognosis. Previous studies have shown that ETO2::GLIS2 can efficiently induce leukemia development associated with strong transcriptional changes but those amenable to pharmacological targeting remained to be identified. By studying an inducible ETO2::GLIS2 cellular model, we uncovered that de novo ETO2::GLIS2 expression in human cells led to increased CASP3 transcription, CASP3 activation, and cell death. Patient-derived ETO2::GLIS2+ leukemic cells expressed both high CASP3 and high BCL2. While BCL2 inhibition partly inhibited ETO2::GLIS2+ leukemic cell proliferation, BH3 profiling revealed that it also sensitized these cells to MCL1 inhibition indicating a functional redundancy between BCL2 and MCL1. We further show that combined inhibition of BCL2 and MCL1 is mandatory to abrogate disease progression using in vivo patient-derived xenograft models. These data reveal that a transcriptional consequence of ETO2::GLIS2 expression includes a positive regulation of the pro-apoptotic CASP3 and associates with a vulnerability to combined targeting of two BCL2 family members providing a novel therapeutic perspective for this aggressive pediatric AML subgroup.

The Alleviative Efficacy of Vitamins A, C, and E Against Zinc Oxide Nanoparticles-Induced Hepatic Damage by Reducing Apoptosis in Rats

Nanoparticles are vastly exploited in today's technology. However, it is realized that exposure to high concentrations of nanoparticles (NPs) may have adverse effects on human health. According to previous reports, zinc oxide (ZnO) NPs cause toxic effects in tissues via inducing apoptosis. The current work was designed to evaluate possible protective activities of vitamins (Vits) A, C, and E against ZnO NPs-induced apoptosis in the liver of rats. To this aim, fifty-four adult male Wistar rats were randomly distributed into nine groups (n = 6 rats for each group), namely, Control1 (water), Control2 (olive oil), Vit A (1000 IU/kg), Vit C (200 mg/kg), Vit E (100 IU/kg), ZnO (200 mg/kg), ZnO + VitA, ZnO + VitC, and ZnO + VitE. To investigate apoptosis, the mRNA and protein expression of Bcl-2-associated X (Bax) and B-cell lymphoma protein 2 (Bcl-2) were examined by qRT-PCR and western blot techniques. The mRNA and protein expression of TNF-α as well as the activity of caspase 3,7 were also measured. The results revealed that ZnO NPs considerably enhance the ratio of Bax to Bcl-2 mRNA and protein expression as well as the activity of caspase 3,7 compared to the control group. Furthermore, the findings implied that the elevated level of TNF-α may link with ZnO NPs-mediated apoptosis in the liver of rats. More importantly, Vits A, C, and E exhibited ameliorative properties against apoptosis-inducing effects of ZnO NPs. Thus, administration of Vits A, C, and E may be effective in preventing liver damage and apoptosis caused by ZnO NPs.

The study of chemical components in Qishiwei Zhenzhu pills and its anti-apoptotic mechanism in cerebral ischemic based on LC-MS and network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Qishiwei Zhenzhu pills are one of the most representative precious treasure proprietary medicines and have been used for nearly 500 years in clinical practice in Chinese. This medicine can prevent diseases and play a certain role in fighting altitude sickness with cerebral ischemia.

AIM OF THE STUDY

This study used LC-MS to analyse the chemical constituents of Qishiwei Zhenzhu pills, which laid a foundation for the improvement of the quality standard and the basic research of pharmacodynamics substances. This study aims to reveal the mechanism of Qishiwei Zhenzhu pills on cerebral ischemia from the perspective of the inflammatory and apoptotic pathway.

MATERIALS AND METHOD

UPLC-Q-TOF-MS was used to analyse the chemical constituents of Qishiwei Zhenzhu pills qualitatively. HPLC-QQQ-MS was used to analyse the contents of Qishiwei Zhenzhu pills quantitatively. The therapeutic target and pathway of Qishiwei Zhenzhu pills in the treatment of ischemic stroke were predicted on the basis of network pharmacology. On the basis of the MCAO rat model, the cerebral infarction rate (TTC staining) and the number of Nissl bodies (toluidine blue staining) were measured, the pathological morphologies of cortex and hippocampus were observed (HE staining), and the mRNA levels were determined by RT-PCR. The protein expressions of Bax, Bcl-2, and Caspase3 in the ischemic brain tissue of rats were determined using the WB method.

RESULTS

A total of 42 chemical constituents, including 11 triterpenoids, 10 flavonoids, 8 organic acids and their derivatives, 4 diterpenoids, 4 tannins, 2 steroids, and 3 other components, were identified from Qishiwei Zhenzhu pills by UPLC-Q-TOF-MS. HPLC-QQQ-MS results found that among the 16 different batches, the content difference between the two batches of preparations with the national drug approval number was small and that the quality was stable. However, significant differences were observed among the preparations of nine medical institutions. Network pharmacology study found that the effect of Qishiwei Zhenzhu pills might be related to the AGE-rage and tumour necrosis factor signalling pathways. Qishiwei Zhenzhu pills could improve the neurobehavioral abnormalities of MCAO rats, reduce the rate of cerebral infarction, improve the pathological changes in the hippocampal area of brain tissue, and increase the number of Nissl body in the brain tissue. Qishiwei Zhenzhu pills tended to reduce the mRNA transcription levels of Bax, Caspase-3, p65, c-fos and VEGF-A and increase the expression of Bcl-2 and MAPK8 mRNA. Moreover, the Bax protein expression tended to decrease, and the bcl-2 protein expression tended to increase.

CONCLUSIONS

A total of 42 chemical components were qualitatively identified from Qishiwei Zhenzhu pills, and 16 chemical components from 16 batches were determined. These components improved the quality standard level of Qishiwei Zhenzhu pills and provided reference for the later exploration of its pharmacodynamics substance basis. The protective mechanism of Qishiwei Zhenzhu pills against ischemic stroke might be related to the downregulation of the apoptosis factor caspase-3.

Acquired mutations in BAX confer resistance to BH3-mimetic therapy in acute myeloid leukemia

Randomized trials in acute myeloid leukemia (AML) have demonstrated improved survival by the BCL-2 inhibitor venetoclax combined with azacitidine in older patients, and clinical trials are actively exploring the role of venetoclax in combination with intensive chemotherapy in fitter patients with AML. As most patients still develop recurrent disease, improved understanding of relapse mechanisms is needed. We find that 17% of patients relapsing after venetoclax-based therapy for AML have acquired inactivating missense or frameshift/nonsense mutations in the apoptosis effector gene BAX. In contrast, such variants were rare after genotoxic chemotherapy. BAX variants arose within either leukemic or preleukemic compartments, with multiple mutations observed in some patients. In vitro, AML cells with mutated BAX were competitively selected during prolonged exposure to BCL-2 antagonists. In model systems, AML cells rendered deficient for BAX, but not its close relative BAK, displayed resistance to BCL-2 targeting, whereas sensitivity to conventional chemotherapy was variable. Acquired mutations in BAX during venetoclax-based therapy represent a novel mechanism of resistance to BH3-mimetics and a potential barrier to the long-term efficacy of drugs targeting BCL-2 in AML.

CD142 promotes trophoblast cell migration by inhibiting BCL2-related autophagic degradation of IL-8

The maintenance of migration of trophoblast cells is beneficial to pregnancy, and its weakening can lead to preeclampsia (PE). CD142 is considered as a classical motility-promoting factor. Our research aimed to explore the role of CD142 in trophoblast cell migration and potential mechanism. Through fluorescence-activated cell sorting (FACS) and gene transduction assays, CD142 expression levels of mouse trophoblast cell lines were upregulated and downregulated respectively. Then, the migratory level was detected through Transwell assays in different groups of trophoblast cells. The corresponding chemokines were screened by ELISA in different sorted trophoblast cells. Based on gene overexpression and knockdown assays, the production mode of identified valuable chemokine was analyzed by detecting gene and protein expression in trophoblast cells. Finally, the contribution of autophagy response to specific chemokine regulated by CD142 was explored by combining different groups of cells and autophagy regulators. Our results showed that both CD142 positive sorting and CD142 overexpression promoted the migratory ability of trophoblast cells, and trophoblast cells with the highest level of CD142 had the strongest migratory ability. In addition, CD142+ cells contained the highest level of IL-8. Consistently, CD142 overexpression promoted IL-8 protein expression in trophoblast cells while CD142 silencing was contrary. However, both CD142 overexpression and CD142 silencing did not affect IL-8 mRNA expression. Moreover, both CD142+ and CD142-overexpressed cells showed higher BCL2 protein expression and poorer autophagic activity. Importantly, autophagy activation with TAT-Beclin1 recovered the increased IL-8 protein expression in CD142+ cells. Obviously, the migratory ability of CD142+ cells inhibited by TAT-Beclin1 was recovered by the addition of IL-8 recombinant factor. In conclusion, CD142 inhibits the degradation of IL-8 through the inhibition of BCL2-Beclin1-autophagy signal transduction, thereby promoting the migration of trophoblast cells.

Endogenous and imposed determinants of apoptotic vulnerabilities in cancer

The intrinsic apoptosis pathway is controlled by the BCL-2 family of proteins. Although the pro-survival members of this family can help cancer cells evade apoptosis, they may also produce apoptotic vulnerabilities that can potentially be exploited therapeutically. Apoptotic vulnerabilities can be driven by endogenous factors including altered genetics, signaling, metabolism, structure and lineage or differentiation state as well as imposed factors, the most prominent being exposure to anti-cancer agents. The recent development of BH3 mimetics that inhibit pro-survival BCL-2 family proteins has allowed these apoptotic vulnerabilities to be targeted with demonstrable clinical success. Here, we review the key concepts that are vital for understanding, uncovering, and exploiting apoptotic vulnerabilities in cancer for the potential improvement of patient outcomes.

Expression profile of the proapoptotic protein Bax in the human brain

Bax is a well-known universal proapoptotic protein. Bax protein is detected in almost all human organs, and its expression levels can be correlated with disease progression and therapeutic efficacy in certain settings. Interestingly, increasing evidence has shown that mature neuronal cell death is often not typical apoptosis. Most results on the expression of Bax proteins (predominantly Baxα) in the human brain come from disease-oriented studies, and the data on Bax protein expression in the normal brain are limited and lack consistency due to many variable factors. Here, we analyzed Bax RNA and protein expression data from multiple databases and performed immunostaining of over 80 samples from 25 healthy subjects across 7 different brain regions. We found that Bax protein expression was heterogeneous across brain regions and individual subjects. Both neurons and glial cells, such as astrocytes, could be Bax positive, but Bax positivity appeared to be highly selective, even within the same cell type in the same region. Furthermore, Bax proteins could be localized in the cytosol (evenly spread or concentrated to one region), nucleus or nucleolus depending on the cell type. Such variation and distribution in Bax expression suggest that Bax may function differently in the human brain than in other organs.

Autophagy-associated immune dysregulation and hyperplasia in a patient with compound heterozygous mutations in ATG9A

ABBREVIATIONS

BCL2: BCL2 apoptosis regulator; BCL10: BCL10 immune signaling adaptor; CARD11: caspase recruitment domain family member 11; CBM: CARD11-BCL10-MALT1; CR2: complement C3d receptor 2; EBNA: Epstein Barr nuclear antigen; EBV: Epstein-Barr virus; FCGR3A; Fc gamma receptor IIIa; GLILD: granulomatous-lymphocytic interstitial lung disease; HV: healthy volunteer; IKBKB/IKB kinase: inhibitor of nuclear factor kappa B kinase subunit beta; IL2RA: interleukin 2 receptor subunit alpha; MALT1: MALT1 paracaspase; MS4A1: membrane spanning 4-domain A1; MTOR: mechanistic target of rapamycin kinase; MYC: MYC proto-oncogene, bHLH: transcription factor; NCAM1: neural cell adhesion molecule 1; NFKB: nuclear factor kappa B; NIAID: National Institute of Allergy and Infectious Diseases; NK: natural killer; PTPRC: protein tyrosine phosphatase receptor type C; SELL: selectin L; PBMCs: peripheral blood mononuclear cells; TR: T cell receptor; Tregs: regulatory T cells; WT: wild-type.

MiR18a5p aggravates homocysteineinduced myocardial injury via autophagy

OBJECTIVES

Hyperhomocysteinaemia (Hcy) is an independent risk factor for cardiovascular and cerebrovascular diseases. MicroRNA (miR)-18a-5p is closely related to cardiovascular diseases. This study aims to investigate the effects of miR-18a-5p on homocysteine (Hcy)-induced myocardial cells injury.

METHODS

H9c2 cells were transfected with miR-18a-5p mimic/miR-18a-5p mimic negative control (NC) or combined with Hcy for intervention, and untreated cells were set as a control group. The transfection efficiency was verified by real-time RT-PCR, and cell counting kit-8 (CCK-8) assay was used to determine cell viability. Flow cytometry was used to detect apoptosis and reactive oxygen species (ROS) levels. Western blotting was performed to measure the protein levels of microtubule-associated protein 1 light chain 3 (LC3)-I, LC3-II, Beclin1, p62, Bax, Bcl-2, and Notch2. Dual luciferase reporter assay was used to detect the interaction of miR-18a-5p with Notch2.

RESULTS

Compared with the control, treatment with Hcy or transfection with miR-18a-5p mimic alone, or combined treatment with Hcy and miR-18a-5p mimic/miR-18a-5p mimic NC significantly reduced the H9c2 cell viability, promoted apoptosis and ROS production, up-regulated the expressions of Bax and Beclin, down-regulated the expressions of Bcl-2, p62, and Notch2, and increased the ratio of LC3-II/LC3-I (all P<0.05). Compared with the combined intervention of miR-18a-5p mimic NC and Hcy group, the above indexes were more significantly changed in the combined intervention of miR-18a-5p mimic and Hcy group, and the difference between the 2 groups was statistically significant (all P<0.05). There is a targeted binding between Notch2 and miR-18a-5p.

CONCLUSIONS

MiR-18a-5p could induce autophagy and apoptosis via increasing ROS production in cardiomyocytes, and aggravate Hcy-induced myocardial injury. Notch2 is a target of miR-18a-5p.

Cancer-cell-membrane-camouflaged supramolecular self-assembly of antisense oligonucleotide and chemodrug for targeted combination therapy

The anti-apoptotic B-cell lymphoma-2 (Bcl-2) family of proteins are critical regulators of cell death that are overexpressed in many cancer cells, especially in multi-drug resistant cancer cells. Combinatorial gene- and chemotherapies using antisense oligonucleotides (ASOs) to suppress the expression of Bcl-2-family mRNA and restore the sensitivity of the cell to chemodrugs provide a promising pathway for anticancer treatment. However, intrinsic differences between macromolecular ASOs and small molecular chemodrugs make their co-delivery challenging. Moreover, extraneous carriers may induce immunogenicity and inflammation problems. Herein, we develop a targeted nanodrug delivery system using the cationic amphiphilic chemodrug mitoxantrone (Mito), which interacts with Bcl-2 ASO through electrostatic interaction and self-assembles into nanoparticles (NP_[Bcl-2/Mito]), whose size can be controlled by regulating the ratio of ASO and Mito. NP_[Bcl-2/Mito] can protect the ASO from degradation during delivery and combine gene- and chemotherapies to improve the anticancer effect. Furthermore, cancer cell membranes (CCMs) derived from homologous tumors were used to camouflage NP_[Bcl-2/Mito] (NP_[Bcl-2/Mito]@CCM) to achieve immune escape and tumor targeting. Both in vitro and in vivo assessments demonstrate the excellent performance of NP_[Bcl-2/Mito]@CCM for drug-resistant breast tumor therapy. This CCM-camouflaged ASO/chemodrug nanoplatform provides a promising pathway for the targeted delivery of ASOs and chemodrugs for tumor combination therapy.

Hydroponic Ginseng ROOT Mediated with CMC Polymer-Coated Zinc Oxide Nanoparticles for Cellular Apoptosis via Downregulation of BCL-2 Gene Expression in A549 Lung Cancer Cell Line

The unique and tailorable physicochemical features of zinc oxide nanoparticles (ZnO-NPs) synthesized from green sources make them attractive for use in cancer treatment. Hydroponic-cultured ginseng-root-synthesized ZnO-NPs (HGRCm-ZnO NPs) were coated with O-carboxymethyl chitosan (CMC) polymer, which stabilized and enhanced the biological efficacy of the nanoparticles. Nanoparticles were characterized by X-ray diffraction (XRD), UV-Vis spectroscopy, transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDS). The flower-shaped nanoparticles were crystalline in nature with a particle size of 28 nm. To evaluate if these NPs had anti-lung cancer activity, analysis was performed on a human lung carcinoma cell line (A549). HGRCm-ZnO nanoparticles showed less toxicity to normal keratinocytes (HaCaTs), at concentrations up to 20 µg/mL, than A549 cancer cells. Additionally, these NPs showed dose-dependent colony formation and cell migration inhibition ability, which makes them more promising for lung cancer treatment. Additionally, Hoechst and propidium iodide dye staining also confirmed that the NP formulation had apoptotic activity in cancer cells. Further, to evaluate the mechanism of cancer cell death via checking the gene expression, HGRCm ZnO NPs upregulated the BAX and Caspase 3 and 9 expression levels but downregulated Bcl-2 expression, indicating that the nanoformulation induced mitochondrial-mediated apoptosis. Moreover, these preliminary results suggest that HGRCm ZnO NPs can be a potential candidate for future lung cancer treatment.

Research on apoptotic mechanism and related pathways involved in postmortem grass carp (Ctenopharyngodon idellus) muscle

BACKGROUND

Apoptosis activation is an essential research to reveal the triggering mechanism of flesh quality deterioration. This study was aimed at explaining apoptotic mechanism of postmortem fish in terms of caspases activation, cytochrome c (cyt-c) release, B-cell lymphoma 2 (Bcl-2) and Bcl2-associated X (Bax) protein levels, transcriptional levels of its molecules, and apoptosis-inducing factor (AIF) translocation at 4 °C for 5 days.

RESULTS

Activation of caspase-9, caspase-8, caspase-3 and the release of mitochondrial cyt-c were observed during storage. The decreased Bcl-2 protein levels, increased Bax protein expressions and Bax/Bcl-2 ratio were major steps for inducing apoptosis. Collectively, transcriptional regulation of Fas ligand (FasL), apoptotic protease activating factor-1 (Apaf-1), inhibitors of apoptosis proteins (IAPs), myeloid cell leukemia-1 (Mcl-1), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) indicated that extrinsic apoptotic pathways (FasL/caspase-8/caspase-3) and intrinsic pathway [(JNK and p38 MAPK)/(Bcl-2, Bax and Mcl-1)/cyt-c/Apaf-1/caspase-9/caspase-3] were involved in apoptotic process. Mitochondrial AIF translocation to nuclear indicated that AIF mediated caspase-independent pathway.

CONCLUSION

Therefore, transcriptional and translational alterations of multiple signaling molecules acted important roles in regulating apoptosis activation in postmortem process. © 2022 Society of Chemical Industry.

Biclonal Diffuse Large B-cell Lymphoma Commonly Characterized by Partial Trisomy 18q Involving MALT1 and BCL2

A 68-year-old man was admitted because of a left shoulder mass and swollen right testis. Pathological examinations indicated a diagnosis of diffuse large B-cell lymphoma (DLBCL) with the CD20+BCL6+MUM1+BCL2+CD10-MYC- phenotype in both lesions. G-banding of soft tissue showed 47,XY,+18, whereas testicular cells showed 47,X,+X,-Y,der (4) t (4;18) (p15;?),del (5) (q?),+13. Fluorescence in situ hybridization detected additional MALT1 and BCL2 signals in both lesions. Southern blot demonstrated different IGH rearrangements between the soft tissue and testis. The patient was diagnosed with biclonal DLBCL with different karyotypes but similar immunophenotypes. Partial trisomy 18q involving MALT1 and BCL2 may be commonly involved in the pathogenesis of this biclonal DLBCL.

HOXB9 Overexpression Confers Chemoresistance to Ovarian Cancer Cells by Inducing ERCC-1, MRP-2, and XIAP

The purpose of this study was to identify the role of HOXB9 and associated molecular mechanism in acquiring chemoresistance to ovarian cancer cells. After establishing HOXB9-overexpressing cells (HOXB9-OE/SKOV3), cisplatin resistance-induced cells (Cis-R/SKOV3), and an ovarian cancer xenograft mouse model, the effects of HOXB9 were evaluated in vitro and in vivo. Expression levels of ERCC-1, MRP-2, XIAP, and Bax/Bcl-2 were assessed as putative mechanisms mediating chemoresistance. Cisplatin-induced apoptosis was significantly decreased in HOXB9-OE/SKOV3 compared to SKOV3. Cisplatin treatment of SKOV3 strongly induced ERCC-1, MRP-2, and XIAP, and apoptosis was strongly induced through the inhibition of Bcl-2 and activation of Bax. ERCC-1, MRP-2, XIAP, and Bcl-2 were also strongly induced in HOXB9 OE/SKOV3. In contrast to SKOV3, cisplatin treatment alone of HOXB9 OE/SKOV3 did not affect the expression of Bcl-2 and Bax, and consequently, there was no increase in apoptosis. HOXB9 knockdown suppressed the expression of ERCC-1 and XIAP, but did not affect MRP-2 and Bcl-2/Bax expression in HOXB9 OE/SKOV3 and Cis-R/SKOV3, and caused a small increase in apoptosis. Treatment of SKOV3 with both cisplatin and siRNA_HOXB9 led to complete suppression of ERCC-1, MRP-2, and XIAP, and significantly increased apoptosis through inhibition of Bcl-2 expression and activation of Bax. The results observed in Cis-R/SKOV3 were similar to that in HOXB9 OE/SKOV3. Our data suggest that HOXB9 overexpression may cause chemoresistance in ovarian cancer cells by differential induction of ERCC-1, MRP-2, and XIAP depending on the strength of HOXB9 expression through inhibition of the mitochondrial pathway of apoptosis, including Bax/Bcl-2.

Distinct Genetically Determined Origins of Myd88/BCL2-Driven Aggressive Lymphoma Rationalize Targeted Therapeutic Intervention Strategies

Genomic profiling revealed the identity of at least 5 subtypes of diffuse large B-cell lymphoma (DLBCL), including the MCD/C5 cluster characterized by aberrations in MYD88, BCL2, PRDM1, and/or SPIB. We generated mouse models harboring B cell-specific Prdm1 or Spib aberrations on the background of oncogenic Myd88 and Bcl2 lesions. We deployed whole-exome sequencing, transcriptome, flow-cytometry, and mass cytometry analyses to demonstrate that Prdm1- or Spib-altered lymphomas display molecular features consistent with prememory B cells and light-zone B cells, whereas lymphomas lacking these alterations were enriched for late light-zone and plasmablast-associated gene sets. Consistent with the phenotypic evidence for increased B cell receptor signaling activity in Prdm1-altered lymphomas, we demonstrate that combined BTK/BCL2 inhibition displays therapeutic activity in mice and in five of six relapsed/refractory DLBCL patients. Moreover, Prdm1-altered lymphomas were immunogenic upon transplantation into immuno-competent hosts, displayed an actionable PD-L1 surface expression, and were sensitive to antimurine-CD19-CAR-T cell therapy, in vivo.

SIGNIFICANCE

Relapsed/refractory DLBCL remains a major medical challenge, and most of these patients succumb to their disease. Here, we generated mouse models, faithfully recapitulating the biology of MYD88-driven human DLBCL. These models revealed robust preclinical activity of combined BTK/BCL2 inhibition. We confirmed activity of this regimen in pretreated non-GCB-DLBCL patients. See related commentary by Leveille et al., p. 8. This article is highlighted in the In This Issue feature, p. 1.

Phylogenetic analysis of the MCL1 BH3 binding groove and rBH3 sequence motifs in the p53 and INK4 protein families

B-cell lymphoma 2 (Bcl-2) proteins are central, conserved regulators of apoptosis. Bcl-2 family function is regulated by binding interactions between the Bcl-2 homology 3 (BH3) motif in pro-apoptotic family members and the BH3 binding groove found in both the pro-apoptotic effector and anti-apoptotic Bcl-2 family members. A novel motif, the reverse BH3 (rBH3), has been shown to interact with the anti-apoptotic Bcl-2 homolog MCL1 (Myeloid cell leukemia 1) and have been identified in the p53 homolog p73, and the CDK4/6 (cyclin dependent kinase 4/6) inhibitor p18INK4c, (p18, cyclin-dependent kinase 4 inhibitor c). To determine the conservation of rBH3 motif, we first assessed conservation of MCL1's BH3 binding groove, where the motif binds. We then constructed neighbor-joining phylogenetic trees of the INK4 and p53 protein families and analyzed sequence conservation using sequence logos of the rBH3 locus. This showed the rBH3 motif is conserved throughout jawed vertebrates p63 and p73 sequences and in chondrichthyans, amphibians, mammals, and some reptiles in p18. Finally, a potential rBH3 motif was identified in mammalian and osteichthyan p19INK4d (p19, cyclin dependent kinase 4 inhibitor d). These findings demonstrate that the interaction between MCL1 and other cellular proteins mediated by the rBH3 motif may be conserved throughout jawed vertebrates.

A role for BCL2L13 and autophagy in germline purifying selection of mtDNA

Mammalian mitochondrial DNA (mtDNA) is inherited uniparentally through the female germline without undergoing recombination. This poses a major problem as deleterious mtDNA mutations must be eliminated to avoid a mutational meltdown over generations. At least two mechanisms that can decrease the mutation load during maternal transmission are operational: a stochastic bottleneck for mtDNA transmission from mother to child, and a directed purifying selection against transmission of deleterious mtDNA mutations. However, the molecular mechanisms controlling these processes remain unknown. In this study, we systematically tested whether decreased autophagy contributes to purifying selection by crossing the C5024T mouse model harbouring a single pathogenic heteroplasmic mutation in the tRNAAla gene of the mtDNA with different autophagy-deficient mouse models, including knockouts of Parkin, Bcl2l13, Ulk1, and Ulk2. Our study reveals a statistically robust effect of knockout of Bcl2l13 on the selection process, and weaker evidence for the effect of Ulk1 and potentially Ulk2, while no statistically significant impact is seen for knockout of Parkin. This points at distinctive roles of these players in germline purifying selection. Overall, our approach provides a framework for investigating the roles of other important factors involved in the enigmatic process of purifying selection and guides further investigations for the role of BCL2L13 in the elimination of non-synonymous mutations in protein-coding genes.

HDL-Chitosan Nanoparticles for siRNA Delivery as an SR-B1 Receptor Targeted System

AIMS

High-Density Lipoprotein (HDL) is a complex structure unique to the human body. ApoA-1 protein is a significant structural/functional protein of HDL and provides a natural interaction with the SR-B1 receptors on the cell membrane. The overexpression of the SR-B1 receptor in the membrane of malignant cells suggests that targeting cancer cells can be possible using HDL. The objective of this study was to prepare HDL-conjugated chitosan nanoparticles containing a genetic material that can be used for liver cancer.

METHODS

HDL used in the preparation of the formulations have been obtained by isolating from blood samples taken from healthy volunteers. Bcl-2 siRNA inhibiting BCL-2 oncogene was selected as the genetic material. Chitosan nanoparticles were prepared using the ionic gelation method utilizing low molecular weight chitosan. Physicochemical properties of formulations, transfection efficacy, and cytotoxicity of them on 3T3 and HepG2 cell lines were examined.

RESULTS

The average diameters of the selected formulations were below 250 nm with a positive zeta potential value between +36 ± 0.1 and +34 ± 0.5 mV. All formulations protected Bcl-2 siRNA from enzymatic degradation in the presence of serum. Cellular uptake ratios of particles by HepG2 cells were found to be between 76% and 98%. HDL/chitosan nanoparticles/Bcl-2 siRNA complex was found to be more toxic when compared to chitosan nanoparticles/Bcl-2 siRNA complex and naked Bcl-2 siRNA.

CONCLUSION

According to attained results, the HDL-conjugated chitosan nanoparticles can bring advantages for targeted siRNA delivery to malignant cells that overexpress SR-B1 receptors, such as HepG2.

Prognostic impact of miR-125b and miR-155b and their relationship with MYC and TP53 in diffuse large B-cell lymphoma: cell-of-origin classification matters

Tumoral microRNAs, such as miR-125b and miR-155b, are important gene expression regulators with complex pathogenetic mechanisms. However, their role in DLBCL, especially when cell-of-origin classification is considered, are still to be elucidated. In a series of 139 DLBCL cases considering germinal center (GC) versus nonGC subtypes, we investigated miR-125b and miR-155b expression by in situ hibridization and their association with some immunophenotypic presentations, including MYC, BCL2 and TP53 expression, MYC, BCL2 and BCL6 translocation status, as well as clinicopathological features and outcomes. miR-125b detection was positively correlated to the Ki-67 index (P = 0.035) in the nGC. Considering the GC subgroup, the percentage of miR-125b positive cells was also correlated to either MYC and MYC/BCL2 double expression (P = 0.047 and P = 0.049, respectively). When it comes to nGC patients, miR-155b percentage and intensity, as well as Allred score, were positively correlated to disease progression (P = 0.038, P = 0.057 and P = 0.039, respectively). In a multivariate analysis, GC phenotype was a significant independent factor associated with higher OS (P = 0.007) and, considering the nGC group, although not significant, the expression of TP53, miR-125b and miR-155b seems to be potential prognostic biomarkers in these tumors. This study demonstrated different pathways based on cell-of-origin classification and highlighted different clinical outcomes. miR-125b, miR-155b and TP53 expression may also represent potential prognostic factors in nGC-DLBCL.

Upregulation of miR-144-3p alleviates Doxorubicin-induced heart failure and cardiomyocytes apoptosis via SOCS2/PI3K/AKT axis

MicroRNAs (miRs) are implicated in heart failure (HF). Thereby, we aim to uncover the role of miR-144-3p in HF. Doxorubicin (Dox)-induced HF model was constructed in rats and cardiomyocytes H9C2, and the cardiac function was determined using ultrasound cardiogram. Morphology of cardiac tissue was observed using hematoxylin-eosin (H&E) staining. The viability and apoptosis of Dox-treated and transfected cardiomyocytes were determined using Cell Counting Kit-8 (CCK-8) assay and flow cytometry. Relative expressions of the HF-associated miRs (including miR-144-3p), suppressor of cytokine signaling 2 (SOCS2), apoptosis- and phosphoinositide 3-kinase (PI3K)/AKT pathway-related factors (B-cell lymphoma 2, Bcl-2; Bcl-2 associated X protein, Bax; cleaved [C] capsase-3; phosphoinositide 3-kinase, PI3K; phosphorylated-PI3K, p-PI3K; p-AKT; AKT) were measured with quantitative real-time polymerase chain reaction or Western blot. Target gene of miR-144-3p was predicted by Starbase and TargetScan and confirmed with dual-luciferase reporter assay. Dox caused rat cardiac dysfunction, aggravated cardiac injury, decreased cardiomyocytes viability, and the expression of miR-144-3p, Bcl-2, and phosphorylation of both PI3K and AKT yet the upregulated those of Bax and C caspase-3, which was reversed by upregulating miR-144-3p, whereas downregulating miR-144-3p did oppositely. SOCS2 was the target gene of miR-144-3p, Dox promoted SOCS2 expression, which was reversed by upregulating miR-144-3p, while downregulating miR-144-3p did conversely. In addition, silencing SOCS2 reversed the effects of miR-144-3p downregulation in Dox-treated cardiomyocytes. Upregulating miR-144-3p alleviated Dox-induced cardiac dysfunction and cell apoptosis via targeting SOCS2, providing a novel evidence of miR-144-3p in HF.

Anticancer Compounds from Cyanobacteria and their Implications in Apoptosis

Cyanobacteria have been recognized as a rich source of bioactive metabolites with potential biotechnological applications in the pharmacological industry. The chemically diverse natural compounds or their analogues cause cytotoxicity. They may kill various cancer cells by inducing apoptosis or changing the activation of cell signaling, particularly involving the protein kinase-C family of enzymes, mitochondrial dysfunctions, and oxidative damage. B cell lymphoma 2 (Bcl-2) is an essential component of apoptosis and is an antiapoptotic molecule. The key apoptotic regulators associated with cancer are members of the Bcl-2 protein family, the key member of which is Bcl-2. The Bcl-2 protein is a promising target for the emergence of new anti-tumor therapies because of its critical role in controlling apoptosis. This review explores the significance of Bcl-2 in the onset of cancer; it may be used as a target for developing high-quality drug therapies to treat various tumors. In addition, a number of computational techniques were used to identify novel hit compounds that may act as inhibitors of the apoptotic protein Bcl-2, including virtual screening, toxicity prediction, and drug-likeness analysis. Twenty-three compounds were assessed as potential hits against Bcl-2, and these compounds were subjected to ADMET property prediction. Dendroamide A and Welwitindolinone A appear to be the most stable and effective drugs against Bcl-2 out of all those evaluated. This article gives an overview of the bioactive compounds produced by cyanobacteria that have anticancer properties and may be exploited to create novel anticancer medications in the future.

Effect of Curcumin on the Head and Neck Squamous Cell Carcinoma Cell Line HN5

BACKGROUND

Curcumin has been isolated from the rhizomes of Curcuma longa. Over the years, it has shown outstanding therapeutic potential in various human disorders, including cancers.

OBJECTIVE

The aim is to study curcumin's effects on the apoptosis signaling pathway in the head and neck squamous cell carcinoma (HNSCC) cell line HN5.

METHODS

The cytotoxicity of curcumin on HN5 cells were assessed. In addition, HN5 cells were also treated with curcumin to evaluate its effect on the caspase-8, -9, Bcl-2, Bax, and Stat3 gene expressions.

RESULTS

The results exhibited that cell viability reduced following curcumin treatment in a concentration- dependent manner. Curcumin treatment caused decreased expression of Bcl2, with simultaneous upregulation of the Bax/Bcl2 ratio. Curcumin increased caspase-9 expression, did not affect caspase-8, and decreased Stat3 expression. The induction of the mitochondria-dependent apoptosis pathway of curcumin happened by modulating the expression of Bcl2 and Bax genes, resulting in the caspase-9 activation. Furthermore, curcumin decreased the expression of the Stat3 in HN-5 cells.

CONCLUSIONS

In conclusion, curcumin showed marked anticancer effects in the HN-5 cell line by modulating Stat-3; Bax/Bcl-2 expression in vitro.

Age Related Senescence, Apoptosis, and Inflammation Profiles in Periodontal Ligament Cells from Canine Teeth

OBJECTIVE

The periapical tissues, including periodontal ligament cells (PDLCs) play an important role in repairing the surrounding tissue of the teeth. A decrease in the regenerative potentiality of resident stem cells (PDLCs) has been suggested to be attributed to the decline of pulp regeneration. Therefore, examining the functional changes in periodontal tissue and cells that occur during the aging process is necessary.

METHODS

The changes in the cementum extract (CE) and PDLCs isolated from young and aged dog teeth were evaluated. PDLCs growth rate, senescence markers, p16 and p21, and proinflammatory cytokines, IL-6, IL-1β, and TNF-α, were analyzed by RT-PCR. Bax, an apoptosis marker, Bcl-2, a marker for cell survival, and IL-6 were examined by Western blot analyses to detect their variance expression in the CE.

RESULTS

Our results demonstrated that aged PDLCs exhibit a low growth rate and an increased expression of p16; however, no change has been demonstrated in the expression of p21. The chronic inflammatory molecules, IL-6 and TNF-α, were significantly upregulated compared to young PDLCs. Western blot analyses showed decreased expression of Bcl-2 in the CE of the aged tooth (p < 0.001).

CONCLUSION

Taken together, aging influences the functional changes of PDLCs and CE and increases senescence, chronic inflammation, and apoptosis markers. As a result, donor age is a key factor influencing the utilization of PDLCs for tooth regeneration.