Bcl-2-family proteins and hematologic malignancies: history and future prospects. Blood. 2008;111:3322-3330. [PMID: 18362212 DOI: 10.1182/blood-2007-09-078162]

Carbazole Derivatives Binding to Bcl-2 Promoter Sequence G-quadruplex

In this study, we used ultraviolet-visible (UV-Vis), fluorescence, and circular dichroism (CD) techniques, as well as molecular modeling, to probe the interactions between carbazole derivatives and the G-quadruplex structure formed in the promoter region of gene Bcl-2. This gene is a rational target for anticancer therapy due to its high expression in a variety of tumors as well as resistance to chemotherapy-induced apoptosis. We employed a sequence with a specific dual G-to-T mutation that may form a mixed-type hybrid G-quadruplex structure in the Bcl-2 P1 promoter region. The three tested carbazole compounds differing in substitution on the nitrogen atom of carbazole interact with the Bcl-2 G-quadruplex by the same binding mode with the very comparable binding affinities in the order of 105 M-1. During absorption and fluorescence measurements, large changes in the ligand spectra were observed at higher G4 concentrations. The spectrophotometric titration results showed a two-step complex formation between the ligands and the G-quadruplex in the form of initial hypochromicity followed by hyperchromicity with a bathochromic shift. The strong fluorescence enhancement of ligands was observed after binding to the DNA. All of the used analytical techniques, as well as molecular modeling, suggested the π-π interaction between carbazole ligands and a guanine tetrad of the Bcl-2 G-quadruplex. Molecular modeling has shown differences in the interaction between each of the ligands and the tested G-quadruplex, which potentially had an impact on the binding strength.

Venetoclax combined with decitabine induced tumor lysis syndrome in a young patient with acute myeloid leukemia: a case report and literature review

Venetoclax, in combination with hypomethylation agents (HMAs), is a novel treatment for leukemia patients with low chemotherapy tolerance. However, it has been reported to be a risk of causing tumor lysis syndrome (TLS) in chronic lymphocytic leukemia (CLL) and elderly acute myeloid leukemia (AML) patients. Here we report a rare case of a young adult AML patient who induced TLS after receiving a combination therapy of venetoclax with decitabine (DEC). A 36-year-old male patient presented with an unexplained fever and was diagnosed with AML-M5a. The patient was first treated with a combination of antibiotics, including voriconazole 300 mg Q12h. After the infection was relieved, he was treated with 100 mg venetoclax in combination with 75 mg/m 2 DEC. However, 12 h after the first treatment, he developed diarrhea, fatigue and other symptoms, and the laboratory results were consistent with the laboratory TLS. The patient stopped chemotherapy immediately, and TLS gradually improved after receiving rehydration, diuresis, dialysis and other treatments. Finally, the patient achieved complete remission. Based on the experience of this case and related studies, we recommend the prevention of TLS should not be limited to elderly patients taking venetoclax, and it is equally important in young patients. And reduce the dosage of venetoclax when using azole antifungal drugs.

Design, Synthesis, and Evaluation of BCL-2 Targeting PROTACs

BCL-2, a member of the BCL-2 protein family, is an antiapoptotic factor that regulates the intrinsic pathway of apoptosis. Due to its aberrant activity, it is frequently implicated in haematopoietic cancers and represents an attractive target for the development of therapeutics that antagonize its activity. A selective BCL-2 inhibitor, venetoclax, was approved for treating chronic lymphocytic leukaemia, acute myeloid leukemia, and other haematologic malignancies, validating BCL-2 as an anticancer target. Since then, alternative therapeutic approaches to modulate the activity of BCL-2 have been explored, such as antibody-drug conjugates and proteolysis-targeting chimeras. Despite numerous research groups focusing on developing degraders of BCL-2 family member proteins, selective BCL-2 PROTACs remain elusive, as disclosed compounds only show dual BCL-xL/BCL-2 degradation. Herein, we report our efforts to develop BCL-2 degraders by incorporating two BCL-2 binding moieties into chimeric compounds that aim to hijack one of three E3 ligases: CRBN, VHL, and IAPs. Even though our project did not result in obtaining a potent and selective BCL-2 PROTAC, our research will aid in understanding the narrow chemical space of BCL-2 degraders.

Molecular mechanisms of extracellular-ATP-mediated colorectal cancer progression: Implication of purinergic receptors-mediated nucleocytoplasmic shuttling of HuR

One of the leading causes of cancer-related deaths worldwide is colorectal cancer (CRC). Extracellular ATP (e-ATP) and purinergic receptors (P2R) play a central role in CRC proliferation and progression. Human antigen R (HuR) is becoming more and more understood to be essential for the expression of genes linked to cancer. The current study demonstrates that ATP can mediate CRC (Caco-2 cells) progression via induction of HuR nucleocytoplasmic shuttling and subsequent expression of cancer-related genes, a consequence mostly mediated via the P2R receptor. It was also noted that suppression of HuR activity by using dihydrotanshinone I (DHTS) prevents cancer-related gene expression and subsequent CRC (Caco-2 cells) progression induced by ATP. The expression of cyclin A2/cyclin-dependent kinase 2 (CDK2), Bcl-2, ProT-α, hypoxia-inducible factor1-α (HIF1-α), vascular endothelial growth factor A (VEGF-A), transforming growth factor-β (TGF-β) and matrix metallopeptidase 9 (MMP-9) induced by ATP were highly reduced in the presence of either PPADS (non-selective P2R antagonist) or DHTS. In addition, e-ATP-induced Caco-2 cell proliferation as well as cell survival were highly reduced in the presence of either PPADS or DHTS or selective CDK-2 inhibitor (Roscovitine) or selective Bcl-2 inhibitor (ABT-263). Furthermore, it was found that MMP-9 is critical for Caco-2 cells migration induced by e-ATP as demonstrated by a clear reduction in cells migration in the presence of a selective MMP-9 inhibitor (Marimastat). Collectively, these data demonstrate that ATP through P2R activation can induce HuR nucleocytoplasmic shuttling that could be translated into an increase in cancer-related genes expression and subsequent, cell proliferation and progression.

AMPK inhibition sensitizes acute leukemia cells to BH3 mimetic-induced cell death

BH3 mimetics, including the BCL2/BCLXL/BCLw inhibitor navitoclax and MCL1 inhibitors S64315 and tapotoclax, have undergone clinical testing for a variety of neoplasms. Because of toxicities, including thrombocytopenia after BCLXL inhibition as well as hematopoietic, hepatic and possible cardiac toxicities after MCL1 inhibition, there is substantial interest in finding agents that can safely sensitize neoplastic cells to these BH3 mimetics. Building on the observation that BH3 mimetic monotherapy induces AMP kinase (AMPK) activation in multiple acute leukemia cell lines, we report that the AMPK inhibitors (AMPKis) dorsomorphin and BAY-3827 sensitize these cells to navitoclax or MCL1 inhibitors. Cell fractionation and phosphoproteomic analyses suggest that sensitization by dorsomorphin involves dephosphorylation of the proapoptotic BCL2 family member BAD at Ser75 and Ser99, leading BAD to translocate to mitochondria and inhibit BCLXL. Consistent with these results, BAD knockout or mutation to BAD S75E/S99E abolishes the sensitizing effects of dorsomorphin. Conversely, dorsomorphin synergizes with navitoclax or the MCL1 inhibitor S63845 to induce cell death in primary acute leukemia samples ex vivo and increases the antitumor effects of navitoclax or S63845 in several xenograft models in vivo with little or no increase in toxicity in normal tissues. These results suggest that AMPK inhibition can sensitize acute leukemia to multiple BH3 mimetics, potentially allowing administration of lower doses while inducing similar antineoplastic effects.

Synthesis, DPPH Radical Scavenging, Cytotoxic Activity, and Apoptosis Induction Efficacy of Novel Thiazoles and Bis-thiazoles

BACKGROUND

Heterocyclic materials-containing thiazoles exhibited incredible importance in pharmaceutical chemistry and drug design due to their extensive biological properties.

METHODS

Synthesis of thiazoles and bis-thiazoles from the reaction of 2-((6-Nitrobenzo[ d][1,3]dioxol-5-yl)methylene)hydrazine-1-carbothioamide with hydrazonoyl chlorides in dioxane and in the existence of triethylamine as basic catalyst. The antioxidant, in vitro antiproliferative, and cytotoxicity efficacy of thiazoles and bis-thiazoles were measured.

RESULTS

In this work, novel series of 5-methyl-2-(2-(-(6-nitrobenzo[d][1,3]dioxol-5-yl)methylene) hydrazinyl)-4-(aryldiazenyl)thiazoles (4a-f) were prepared via the reaction of hydrazonoyl chlorides 2a-f with 2-((6-nitrobenzo[d][1,3]dioxol-5-yl)methylene)hydrazine-1-carbothioamide (1) in dioxane and employing triethylamine as basic catalyst. Following the same procedure, bisthiazoles (6, 8, and 10) have been synthesized by utilizing bis-hydrazonoyl chlorides (5, 7, and 9) and carbothioamide 1 in a molar ratio (1:2), respectively. The distinctive features in the structure of isolated products were elucidated by spectroscopic tools and elemental analyses. The antioxidant, in vitro anti-proliferative, cytotoxicity, and anti-cancer efficacy of thiazoles and bis-thiazoles were evaluated. Compounds 4d and 4f were the most potent antioxidant agents. Gene expression of apoptosis markers and fragmentation assay of DNA were assessed to explore the biochemical mechanism of synthesized products. Thiazoles significantly inhibited cell growth and proliferation more than bis-thiazoles. They induced apoptosis through induction of apoptotic gene expression P53 and downregulation of antiapoptotic gene expression Bcl-2. Moreover, they induced fragmentation of DNA in cancer cells, indicating that they could be employed as anticancer agents by inhibiting tumor growth and progression and can be considered effective compounds in the strategy of anti-cancer agents' discovery.

CONCLUSION

Synthesis, DPPH Radical Scavenging, Cytotoxic activity, and Apoptosis Induction Efficacy based on Novel Thiazoles and Bis-thiazoles.

The mtDNA-STING pathway plays an important role in both navitoclax- and S63845-induced autophagy and enhances cell death

Targeting BCL2 family proteins to induce cancer cell death has been successful in the treatment of cancer. BH3 mimetics such as ABT-737 not only induce cell death, but also activate autophagy. The molecular mechanism by which the BH3 mimetics induce autophagy is still controversial. In this study, we show that the BCL2/BCLXL/BCLw inhibitor navitoclax and the MCL1 inhibitor S63845 induce both apoptosis and autophagy in mouse embryonic fibroblasts (MEFs) and leukemia cell lines, while autophagy induced by navticlax and S63845 in leukemia cell lines requires the inhibition of caspase activities. Further experiments demonstrate that the autophagy induced by navitoclax or S63845 does not depend on Beclin 1, but downstream of Bax/Bak. Moreover, both navitoclax and S63845 treatment induce mtDNA release in MEFs, which activates STING and thereby induces autophagy, while STING KO inhibits both navitoclax- and S63845-induced autophagy. Furthermore, STING KO diminishes navitoclax- or S63845-induced apoptosis, suggesting that STING activation enhances rather than inhibits apoptosis. Thus, our findings provide new insights into the regulations of navitoclax- or S63845-induced autophagy and cell death.

Differential expression pattern of Bcl-2 family members in B and T cells in systemic lupus erythematosus and rheumatoid arthritis

OBJECTIVE

This study aimed to evaluate the expression level of anti-apoptotic Bcl-2 family proteins in B and T cells in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) in relation to disease activity and the effect of various Bcl-2 family inhibitors (BH3 mimetics) as potential treatment.

METHODS

We included 14 SLE patients, 12 RA patients, and 13 healthy controls to study anti-apoptotic Bcl-2, Bcl-XL, and Mcl-1 expression and cell survival in different B and T cell subsets using stimulation assays and intracellular flow cytometry. Effect of various BH3 mimetics was assessed by cell viability analyses.

RESULTS

In SLE, significant differences in Bcl-2 family members were confined to the B cell compartment with decreased induction of Bcl-XL (p ≤ 0.05) and Mcl-1 (p ≤ 0.001) upon CpG stimulation. In RA, we did not observe any differences in expression levels of Bcl-2 family proteins. Expression patterns did not correlate with disease activity apart from decreased induction of Mcl-1 in B cells in active SLE. After in vitro stimulation with CpG, plasmablasts were more viable after treatment with three different BH3 mimetics compared to naïve or memory B cells in control and patient cells. After activation, Mcl-1 inhibition was most effective in reducing plasmablast and T cell viability, however, less in patients than controls.

CONCLUSION

Our study provides evidence for the increased differential expression pattern of Bcl-2 family members in B and T cell subsets of patients with SLE compared to controls. Tested BH3 mimetics showed higher efficacy in controls compared to both autoimmune diseases, though nonsignificant due to low patient numbers.

Altered expression of proteins involved in metabolism in LGMDR1 muscle is lost in cell culture conditions

BACKGROUND

Limb-girdle muscular dystrophy R1 calpain 3-related (LGMDR1) is an autosomal recessive muscular dystrophy due to mutations in the CAPN3 gene. While the pathophysiology of this disease has not been clearly established yet, Wnt and mTOR signaling pathways impairment in LGMDR1 muscles has been reported.

RESULTS

A reduction in Akt phosphorylation ratio and upregulated expression of proteins implicated in glycolysis (HK-II) and in fructose and lactate transport (GLUT5 and MCT1) in LGMDR1 muscle was observed. In vitro analysis to establish mitochondrial and glycolytic functions of primary cultures were performed, however, no differences between control and patients were observed. Additionally, gene expression analysis showed a lack of correlation between primary myoblasts/myotubes and LGMDR1 muscle while skin fibroblasts and CD56- cells showed a slightly better correlation with muscle. FRZB gene was upregulated in all the analyzed cell types (except in myoblasts).

CONCLUSIONS

Proteins implicated in metabolism are deregulated in LGMDR1 patients' muscle. Obtained results evidence the limited usefulness of primary myoblasts/myotubes for LGMDR1 gene expression and metabolic studies. However, since FRZB is the only gene that showed upregulation in all the analyzed cell types it is suggested its role as a key regulator of the pathophysiology of the LGMDR1 muscle fiber. The Wnt signaling pathway inactivation, secondary to FRZB upregulation, and GLUT5 overexpression may participate in the impaired adipogenesis in LGMD1R patients.

Deubiquitinase USP19 modulates apoptotic calcium release and endoplasmic reticulum stress by deubiquitinating BAG6 in triple negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC), a heterogeneous subtype of breast cancer (BC), had poor prognosis. Endoplasmic reticulum (ER) stress was responsible for cellular processes and played a crucial role in the cell function. ER stress is a complex and dynamic process that can induce abnormal apoptosis and death. However, the underlying mechanism of ER stress involved in TNBC is not well defined.

METHODS

We identified ubiquitin-specific protease 19 (USP19) as a TNBC negative regulator for further investigation. The effects of USP19 on BC proliferation were assessed in vitro using proliferation test and cell-cycle assays, while the effects in vivo were examined using a mouse tumorigenicity model. Through in vitro flow cytometric analyses and in vivo TUNEL assays, cell apoptosis was assessed. Proteomics was used to examine the proteins that interact with USP19.

RESULTS

Multiple in vitro and in vivo tests showed that USP19 decreases TNBC cell growth while increasing apoptosis. Then, we demonstrated that USP19 interacts with deubiquitinates and subsequently stabilises family molecular chaperone regulator 6 (BAG6). BAG6 can boost B-cell lymphoma 2 (BCL2) ubiquitination and degradation, thereby raising ER calcium (Ca2+ ) levels and causing ER stress. We also found that the N6 -methyladenosine (m6 A) "writer" methyltransferase-like 14 (METTL14) increased global m6 A modification.

CONCLUSIONS

Our study reveals that USP19 elevates the intracellular Ca2+ concentration to alter ER stress via regulation of BAG6 and BCL2 stability and may be a viable therapeutic target for TNBC therapy.

Chromosomal Instability in Various Generations of Human Mesenchymal Stem Cells Following the Therapeutic Radiation

Background

Radiotherapy is a crucial treatment for most malignancies. However, it can cause several side effects, including the development of secondary malignancies due to radiation-induced genomic instability (RIGI). The aim of this study was to evaluate genomic instability in human mesenchymal stem cells (hMSCs) at different X-ray radiation doses. Additionally, the study aimed to examine the relative expression of certain genes involved in DNA repair, proto-oncogenes, and tumor suppressor genes.

Methods

After extracting, characterizing, and expanding hMSCs, they were exposed to X-ray beams at doses of 0, 0.5, 2, and 6 Gy. Nuclear alterations were evaluated through the cytokinesis-block micronucleus (CBMN) assay at 2, 10, and 15 days postirradiation. The expressions of BRCA1, BRCA2, TP53, Bax, Bcl2, and KRAS genes were analyzed 48 hr after irradiation to evaluate genomic responses to different radiation doses.

Results

The mean incidence of micronuclei, nucleoplasmic bridges, and nuclear buds was 4.8 ± 1.6, 47.6 ± 6, and 18 ± 2.6, respectively, in the nonirradiated group 48 hr after the fourth passage, per 1,000 binucleated cells. The incidence of micronuclei in groups exposed to 0.5, 2, and 6 Gy of radiation was 14.3 ± 4.9, 32.3 ± 6.5, and 55 ± 9.1, respectively, 48 hr after irradiation. The expression levels of the BRCA2, Bax, TP53, and KRAS genes significantly increased after exposure to 6 Gy radiation compared to the control groups. However, there was no significant increase in BRCA1 and Bcl2 gene expression in our study.

Conclusion

This study demonstrated significant nuclear alterations in the 10 days postirradiation due to the RIGIs that they inherited from their irradiated ancestral cells. While chromosomal instability is a prevalent event in malignant cells, so it seems necessary to optimize radiotherapy treatment protocols for tissues that contain stem cells, especially with IMRT, which delivers a low dose to a larger volume of tissues.

Long non-coding RNA SOX2-OT enhances cancer biological traits via sponging to tumor suppressor miR-122-3p and miR-194-5p in non-small cell lung carcinoma

The oncogenic role of long non-coding RNA SOX2 overlapping transcript (SOX2-OT) has been demonstrated as a miRNA decay system that sponges tumor suppressor miRNA, including miR-122-3p in glioblastoma and miR-194-5p in glioblastoma, gastric, and colorectal cancers. However, the molecular function of SOX2-OT remains unknown in most cancers, including lung cancer. In the current study, we aimed to evaluate the downstream regulatory function of SOX2-OT in A549 and Calu-3 lung cancer cell lines. We knocked down SOX2-OT expression using an RNA interference system, which significantly decreased expression in A549 and Calu-3 cells. The expression of down-regulating miRNAs (miR-122-3p and miR-194-5p) was evaluated, revealing increased expression of miR-122-3p and miR-194-5p. Additionally, the expression of miRNAs downstream mRNA, including FOXO1 (Forkhead Box O1) and FOXA1 (Forkhead Box O1), changed. Recently, critical roles of FOXO1 and FOXA1 proteins in pathways involved in proliferation, metastasis and apoptosis have been demonstrated. Downstream changes in cellular traits were assessed using MTT, flow cytometry, metastasis and apoptosis assays. These assessments confirmed that the biological behaviors of lung cancer cells were influenced after SOX2-OT knockdown. In summary, the present study highlights the oncogenic role of SOX2-OT through the regulation of miR-122-3p/FOXO1 and miR-194-5p/FOXA1 pathways.

Two staged phase II clinical trial of Eribulin monotherapy in advanced or recurrent cervical cancer

BACKGROUND

Eribulin a microtubule targeting agent and analog of Halichondrin B, a natural product isolated from marine sponge H. okadai, has proven clinical efficacy in metastatic pretreated breast cancer and liposarcoma. We conducted a 2-stage Phase II study of eribulin in patients with advanced/recurrent cervical cancer to examine its clinical activity and evaluate biomarkers for predictors of response.

METHODS

Women with advanced/recurrent cervical cancer after ≤1 prior chemotherapy regimen, measurable disease and ECOG performance status ≤2 were treated with eribulin (1.4 mg/m² IV day 1 and 8, every 21 days) with tumor assessments every 2 cycles. Primary endpoint was 6-month progression-free survival (PFS6); secondary were best overall response (RECISTv1.1), toxicity (CTCAEv4.03) and overall survival (OS). Exploratory endpoints were associations of biomarkers with clinical activity. Immunohistochemistry was performed on archival tumor samples. Overexpression was defined when both intensity and distribution scores were ≥ 2.

RESULTS

32 patients enrolled from 11/2012-5/2017. 29/32 patients had prior chemotherapy with cisplatin/paclitaxel/bevacizumab (n = 12) or cisplatin/gemcitabine (n = 12) as the most common regimens. 14 patients received prior paclitaxel. 1 (3%) had a complete response, 5 (16%) had a partial response and 13 (41%) had stable disease for ORR of 19% (95% CI 8, 37). Those who are paclitaxel naïve experienced the greatest benefit with a 29% ORR (95% CI 12, 54). Patients who received prior paclitaxel responded less favorably than those who did not (p = .002) and had a shorter PFS and OS. Grade 3/4 adverse events occurring in >10% of patients were anemia (n = 12, 38%), neutropenia (n = 7, 22%) and leukopenia (n = 6, 19%). Analysis of correlative predictors of response revealed that patients who did not overexpress βII and BAX were significantly more likely to respond to e`ribulin. PFS was significantly shorter in patients with βII and BAX overexpression, OS was significantly shorter in those with βIII and BAX overexpression. These associations remained after multivariate analysis.

CONCLUSIONS

Eribulin shows modest activity in patients with recurrent/advanced cervical cancer with a favorable toxicity profile. Prior paclitaxel exposure is associated with decreased eribulin response. βII, βIII tubulin subtypes and BAX are predictors of response and survival. Eribulin may be an option for women with paclitaxel-naïve recurrent/advanced cervical cancer.

Targeting mitochondria as a potential therapeutic strategy against chemoresistance in cancer

The importance of mitochondria is not only limited to energy generation but also in several physical and chemical processes critical for cell survival. Mitochondria play an essential role in cellular apoptosis, calcium ion transport and cellular metabolism. Mutation in the nuclear and mitochondrial genes, altered oncogenes/tumor suppressor genes, and deregulated signalling for cell viability are major reasons for cancer progression and chemoresistance. The development of drug resistance in cancer patients is a major challenge in cancer treatment as the resistant cells are often more aggressive. The drug resistant cells of numerous cancer types exhibit the deregulation of mitochondrial function. The increased biogenesis of mitochondria and its dynamic alteration contribute to developing resistance. Further, a small subpopulation of cancer stem cells in the heterogeneous tumor is primarily responsible for chemoresistance and has an attribute of mitochondrial dysfunction. This review highlights the critical role of mitochondrial dysfunction in chemoresistance in cancer cells through the processes of apoptosis, autophagy/mitophagy, and cancer stemness. Mitochondria-targeted therapeutic strategies might help reduce cancer progression and chemoresistance induced by various cancer drugs.

Potential of siRNA-Bearing Subtilosomes in the Treatment of Diethylnitrosamine-Induced Hepatocellular Carcinoma

Therapeutics, based on small interfering RNA (siRNA), have demonstrated tremendous potential for treating cancer. However, issues such as non-specific targeting, premature degradation, and the intrinsic toxicity of the siRNA, have to be solved before they are ready for use in translational medicines. To address these challenges, nanotechnology-based tools might help to shield siRNA and ensure its specific delivery to the target site. Besides playing a crucial role in prostaglandin synthesis, the cyclo-oxygenase-2 (COX-2) enzyme has been reported to mediate carcinogenesis in various types of cancer, including hepatocellular carcinoma (HCC). We encapsulated COX-2-specific siRNA in Bacillus subtilis membrane lipid-based liposomes (subtilosomes) and evaluated their potential in the treatment of diethylnitrosamine (DEN)-induced hepatocellular carcinoma. Our findings suggested that the subtilosome-based formulation was stable, releasing COX-2 siRNA in a sustained manner, and has the potential to abruptly release encapsulated material at acidic pH. The fusogenic property of subtilosomes was revealed by FRET, fluorescence dequenching, content-mixing assay, etc. The subtilosome-based siRNA formulation was successful in inhibiting TNF-α expression in the experimental animals. The apoptosis study indicated that the subtilosomized siRNA inhibits DEN-induced carcinogenesis more effectively than free siRNA. The as-developed formulation also suppressed COX-2 expression, which in turn up-regulated the expression of wild-type p53 and Bax on one hand and down-regulated Bcl-2 expression on the other. The survival data established the increased efficacy of subtilosome-encapsulated COX-2 siRNA against hepatocellular carcinoma.

Isolation and characterization of N-(2-Hydroxyethyl)hexadecanamide from Colletotrichum gloeosporioides with apoptosis-inducing potential in breast cancer cells

Endophytic fungi are a well-established reservoir of bioactive compounds that are pharmaceutically valuable and therefore, contribute significantly to the biomedical field. The present study aims to identify the bioactive anticancer compound from ethyl acetate extract of fungal endophyte, Colletotrichum gloeosporioides associated with the leaf of the medicinal plant Oroxylum indicum. The fatty acid amide compound N-(2-Hydroxyethyl)hexadecanamide (Palmitoylethanolamide; PEA) was identified using antioxidant activity-guided fractionation assisted with tandem liquid chromatography coupled with quadrupole time of flight mass spectrometry, Fourier transform-infrared spectroscopy, time-of-flight mass spectrometry, and nuclear magnetic resonance. In-Silico molecular docking analysis showed that PEA potentially docked to the active sites of apoptosis-inducing proteins including BAX, BCL-2, P21, and P53. Further validation was done using in vitro study that showed PEA inhibitsthe proliferation, alters nuclear morphology and attenuates the wound closure ability of MDA-MB-231 and MCF-7 cells. PEA induces apoptosis via upregulating cell-cycle arrest (P21), tumor suppression (P53), pro-apoptotic (BAX, CASPASE-8, and FADD) genes, and downregulating anti-apoptotic gene BCL-2. The upregulation of the active form of Caspase-3 was also reported. This is the first-ever report for the isolation of PEA from C. gloeosporioides with anticancer activity against human breast cancer cells and therefore holds great potential for future therapeutics.

BCL-2 protein family: attractive targets for cancer therapy

Acquired resistance to cell death is a hallmark of cancer. The BCL-2 protein family members play important roles in controlling apoptotic cell death. Abnormal over-expression of pro-survival BCL-2 family members or abnormal reduction of pro-apoptotic BCL-2 family proteins, both resulting in the inhibition of apoptosis, are frequently detected in diverse malignancies. The critical role of the pro-survival and pro-apoptotic BCL-2 family proteins in the regulation of apoptosis makes them attractive targets for the development of agents for the treatment of cancer. This review describes the roles of the various pro-survival and pro-apoptotic members of the BCL-2 protein family in normal development and organismal function and how defects in the control of apoptosis promote the development and therapy resistance of cancer. Finally, we discuss the development of inhibitors of pro-survival BCL-2 proteins, termed BH3-mimetic drugs, as novel agents for cancer therapy.

Mechanism of action of Daqinjiao decoction in treating cerebral small vessel disease explored using network pharmacology and molecular docking technology

BACKGROUND AND PURPOSE

Cerebral small vessel disease (CSVD) is a clinically commonly-seen slow-progressing cerebral vascular disease. As a classic Chinese formula for the treatment of stroke, Daqinjiao Decoction (DQJD) is now used to treat CSVD with desirable effect. Since the mechanism of action is still unclear, this article will explore the therapeutic effect and mechanism of action of the formula using network pharmacology technology.

METHODS

The major chemical components and potential target genes of DQJD were screened by bioinformatics. The key targets in CSVD were identified based on network modules. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed. Pharmacodynamics of the decoction was evaluated by establishing a rat model with bilateral common carotid artery occlusion in the brain. Molecular docking, Western blot analysis and quantitative real-time polymerase chain reaction (QRT-PCR) were performed to confirm the effectiveness of targets in related pathways.

RESULTS

Network pharmacology showed that 16 targets and 30 pathways were involved in the DQJD-targeted pathway network. Results revealed that DQJD might play a role by targeting the key targets including Caspse3 and P53 and regulating the P53 signaling pathway. Cognitive function and neuronal cell changes of rats were evaluated using Morris water maze, open field test and HE staining. It was indicated that DQJD could keep the nerve cells intact and neatly arranged. The decoction could improve the memory and learning ability of rats compared with the model group. It decreased the protein and mRNA expression levels of Caspse3 and P53 significantly (p<0.01).

CONCLUSION

The study shows that baicalein, quercetin and wogonin, the effective components of DQJD, may regulate multiple signaling pathways by targeting the targets like Caspse3 and P53 and treat CSVD by reducing the damage to brain nerve cells.

The effects of mifepristone on the structure of human decidua and chorion and Bax and Bcl-2 expression at early stage of pregnancy

Background

As a progesterone receptor antagonist, mifepristone combined with misoprostol is widely used to terminate early pregnancy in clinical practice. It has also been reported that mifepristone may cause cell death in decidual cells and result in hemorrhage of the decidua and insufficient blood supply. However, little is known about the histological effects of mifepristone on human decidua and chorion.

Methods

Histological and subcellular structural changes of decidua and chorionic villi from women taking mifepristone at early pregnancy times were examined by Hematoxylin and eosin (H&E) staining and transmission Electron microscope. The expression of apoptosis-related proteins Bax/Bcl-2 was examined by immunohistochemistry.

Results

After 48 h of mifepristone administration, the decidua tissue and chorionic villus structures were altered in women within 39–49 days of gestation and displayed varying degrees of degeneration and necrosis-like features. Apoptotic events were observed in the decidua and chorionic villi of early pregnancy, and mifepristone treatment significantly increases the number of apoptotic cells. The increased apoptotic events were concomitant with the increased expression of Bax and decreased expression of Bcl-2.

Conclusion

This study provides evidence that mifepristone induces histological and subcellular changes in decidua and chorionic villi. Mifepristone modulates the relative ratio of Bax/Bcl-2 and the increased apoptosis contributes to the pregnancy termination at early stage of pregnancy.

Expression of Bcl-2 and clinicopathological variables in salivary glands mucoepidermoid carcinoma

INTRODUCTION

Mucoepidermoid carcinoma (MEC) has several diagnostic, biological, and histopathological manifestations, each of which presents issues and difficulties in terms of diagnosis, grading, classification, and therapy. The goal of this study was to find out how the anti-apoptotic protein Bcl2 was expressed in salivary gland (SG) MEC and how it related to a number of clinicopathological factors.

METHODS

The present study comprised 30 MECs of the SG lesions that were histopathologically diagnosed. The immunohistochemistry method was used to determine Bcl-2 expression. The spss software version 20.0 was used to find a link between Bcl-2 expression and clinical and histological features.

RESULTS

The patients' average age was 49.93 years, and MEC of SGs was more common in females. The palate was the most commonly involved area, accounting for 13 (43.3%) of cases, followed by the parotid glands, which accounted for 8 (26.7%). High-grade tumors accounted for 14 (46.7%) of the cases, whereas mild-grade tumors accounted for 10 (33.3%) and moderate-grade tumors accounted for 6% (20.0%). Bcl-2 immunostaining was associated with gender (P = 0.047), there was also a significant (P = 0.002) difference in tumor grade and age groups. Furthermore, no significant relationships between Bcl-2 expression and the other variables were discovered.

CONCLUSION

Gender and age affect MEC tumor aggressiveness and grade. High-grade MEC tumors expressed Bcl-2 strongly and moderately, whereas low-grade tumors expressed it moderately. Bcl-2 may predict MEC tumor aggressiveness. MEC therapy may target Bcl-2.

Implication of extrinsic and intrinsic apoptotic pathways in the targeted therapy of hepatocellular carcinoma using aptamer-labeled viramidine nanoparticles

Hepatocellular carcinoma (HCC) is a global health problem with regional differences in epidemiological statistics. Co-assembling the drug nanoparticles and targeting moieties could improve the therapeutic delivery of anti-cancer drugs. In this attempt, we tracked the extrinsic and intrinsic apoptotic pathways in HCC cells using viramidine (VRM)-loaded aptamer (APT) nanoparticles. In these NPs, both APT and VRM act as targeted ligands/drugs to HCC cells. The NPs were characterized using TEM, ESI–MS, FTIR, and ¹H NMR. The results showed uniform particles with round and smooth shapes on the nano-scale. SRB-based cytotoxicity was performed and IC₅₀ values were measured for HCC versus normal cells upon the proposed treatments. The flow cytometry technique was applied to determine apoptosis, then confirmed using genetic and protein analyses. In addition, nitric oxide (NO) and its enzyme (iNOS) were analyzed to examine the effect of reactive nitrogen species (RNS) on apoptosis induction. The present findings indicated that Huh-7 cells were more sensitive to APT-VRM NPs than HepG2 cells, recording the lowest IC₅₀ values (11.23 ± 0.23 µM and 16.69 ± 1.12 µM), as well as the highest significant increase in the apoptotic cells (61.5% and 42%), respectively. Intriguingely, normal BHK-21 cells recorded undetectable IC₅₀ values in the applied NPs, confirming their targeted delivery ability. The genetic expression and protein levels of c-FLIP, Bcl-2, and TNF-α were down-regulated, while FADD, caspase 8, caspase 3, caspase 9, and Bax were up-regulated upon treatment with APT-VRM NPs. The prepared VRM NPs labeled with APT could significantly elevate NO via activation of iNOS. In conclusion, APT-VRM NPs bioconjugate interferes with HCC cells through NO-mediated extrinsic and intrinsic apoptosis.

CircRNA-Associated CeRNAs Regulatory Axes in Retinoblastoma: A Systematic Scoping Review

Retinoblastoma (RB) is one of the most common childhood cancers caused by RB gene mutations (tumor suppressor gene in various patients). A better understanding of molecular pathways and the development of new diagnostic approaches may lead to better treatment for RB patients. The number of studies on ceRNA axes is increasing, emphasizing the significance of these axes in RB. Circular RNAs (circRNAs) play a vital role in competing endogenous RNA (ceRNA) regulatory axes by sponging microRNAs and regulating gene expression. Because of the broadness of ceRNA interaction networks, they may assist in investigating treatment targets in RB. This study conducted a systematic scoping review to evaluate verified loops of ceRNA in RB, focusing on the ceRNA axis and its relationship to circRNAs. This scoping review was carried out using a six-step strategy and the Prisma guideline, and it involved systematically searching the publications of seven databases. Out of 363 records, sixteen articles were entirely consistent with the defined inclusion criteria and were summarized in the relevant table. The majority of the studies focused on the circRNAs circ_0000527, circ_0000034, and circTET1, with approximately two-fifths of the studies focusing on a single circRNA. Understanding the many features of this regulatory structure may help elucidate RB’s unknown causative factors and provide novel molecular potential therapeutic targets and medical fields.

Insulin, Muscle Glucose Uptake, and Hexokinase: Revisiting the Road Not Taken

Research conducted over the last 50 yr has provided insight into the mechanisms by which insulin stimulates glucose transport across the skeletal muscle cell membrane Transport alone, however, does not result in net glucose uptake as free glucose equilibrates across the cell membrane and is not metabolized. Glucose uptake requires that glucose is phosphorylated by hexokinases. Phosphorylated glucose cannot leave the cell and is the substrate for metabolism. It is indisputable that glucose phosphorylation is essential for glucose uptake. Major advances have been made in defining the regulation of the insulin-stimulated glucose transporter (GLUT4) in skeletal muscle. By contrast, the insulin-regulated hexokinase (hexokinase II) parallels Robert Frost's "The Road Not Taken." Here the case is made that an understanding of glucose phosphorylation by hexokinase II is necessary to define the regulation of skeletal muscle glucose uptake in health and insulin resistance. Results of studies from different physiological disciplines that have elegantly described how hexokinase II can be regulated are summarized to provide a framework for potential application to skeletal muscle. Mechanisms by which hexokinase II is regulated in skeletal muscle await rigorous examination.

Chitosan Containing Nano Zn-Organic Framework: Synthesis, Characterization and Biological Activity

A biologically active agent based on a Zn-1,3,5-benzen tricarboxylic acid (Zn-BTC) framework incorporated into a chitosan (CS) biopolymer (Zn-BTC@CS) was successfully synthesized using a microwave irradiation technique. The synthesized Zn-BTC@CS was characterized using a scanning electron microscope (SEM) and the obtained data indicated a highly smooth surface morphology of the synthesized Zn-BTC and no morphological changes when the Zn-BTC covered the CS. In addition, the particle size diameter varied from 20 to 40 nm. XRD displayed a well-maintained Zn-BTC structure, and the crystal structure of Zn-BTC was not distorted by the composition of Zn-BTC and chitosan in the nanocomposite. Data from BET analysis revealed that the specific surface area of the Zn-BTC was reduced from 995.15 m²/g to 15.16 m²/g after coating with chitosan. The pore size distribution and pore volume of the Zn-BTC, Zn-BTC@CS were centered at 37.26 nm and at 22.5 nm, respectively. Zn-BTC@CS exhibited anticancer efficacy against lung and colon cancer cell lines. Zn-BTC@CS inhibited the proliferation of A549 and DLD-1 cancer cell lines in a dose-dependent manner with IC₅₀ values of 13.2 and 19.8 µg/mL for the colon and lung cancer cell lines, respectively. Zn-BTC@CS stimulated the apoptotic process through up-regulating P53 expression and down-regulating Bcl-2 expression. Moreover, Zn-BTC@CS induced in vitro DNA fragmentation in both cancer cell lines with significantly different affinity by 66% (A549) and 20% (DLD-1) versus 52% reduction by Cisplatin. Zn-BTC@CS (IC50) exhibited anti-invasive activity and dramatically inhibited the migration of lung and colon cancer cell lines. This study provides evidence that Zn-BTC@CS targets the essential proteins involved in proliferation, metastasis, and apoptosis. Thus, Zn-BTC@CS has chemotherapeutic potential for inhibiting lung and colon cancer viability and growth.

The Ribosomal Protein L5 Functions During Xenopus Anterior Development Through Apoptotic Pathways

Ribosomal biogenesis is a fundamental process necessary for cell growth and division. Ribosomal protein L5 (Rpl5) is part of the large ribosomal subunit. Mutations in this protein have been associated with the congenital disease Diamond Blackfan anemia (DBA), a so called ribosomopathy. Despite of the ubiquitous need of ribosomes, clinical manifestations of DBA include tissue-specific symptoms, e.g., craniofacial malformations, eye abnormalities, skin pigmentation failure, cardiac defects or liver cirrhosis. Here, we made use of the vertebrate model organism Xenopus laevis and showed a specific expression of rpl5 in the developing anterior tissue correlating with tissues affected in ribosomopathies. Upon Rpl5 knockdown using an antisense-based morpholino oligonucleotide approach, we showed different phenotypes affecting anterior tissue, i.e., defective cranial cartilage, malformed eyes, and microcephaly. Hence, the observed phenotypes in Xenopus laevis resemble the clinical manifestations of DBA. Analyses of the underlying molecular basis revealed that the expression of several marker genes of neural crest, eye, and brain are decreased during induction and differentiation of the respective tissue. Furthermore, Rpl5 knockdown led to decreased cell proliferation and increased cell apoptosis during early embryogenesis. Investigating the molecular mechanisms underlying Rpl5 function revealed a more than additive effect between either loss of function of Rpl5 and loss of function of c-Myc or loss of function of Rpl5 and gain of function of Tp53, suggesting a common signaling pathway of these proteins. The co-injection of the apoptosis blocking molecule Bcl2 resulted in a partial rescue of the eye phenotype, supporting the hypothesis that apoptosis is one main reason for the phenotypes occurring upon Rpl5 knockdown. With this study, we are able to shed more light on the still poorly understood molecular background of ribosomopathies.

A review on the treatment of multiple myeloma with small molecular agents in the past five years

Multiple myeloma is currently incurable, and the incidence rate is increasing year by year worldwide. Although in recent years the combined treatment plan based on proteasome inhibitors and immunomodulatory drugs has greatly improved the treatment effect of multiple myeloma, most patients still relapse and become resistant to current treatments. To solve this problem, scientists are committed to developing drugs with higher specificity, such as iberdomide, which is highly specific to ikaros and aiolos. This review aims to focus on the small molecular agents that are being researched/clinically used for the treatment of multiple myeloma, including the target mechanism, structure-activity relationship and application prospects of small molecular agents.

METTL3 mediates chemoresistance by enhancing AML homing and engraftment via ITGA4

Chemoresistant leukemia relapse is one of the most common causes of death for acute myeloid leukemia (AML) patients and the homing/engraftment in bone marrow (BM) are crucial steps for AML cells to acquire chemoresistance by interacting with stromal cell components. No crosstalk between m⁶A modification and homing/engraftment has been reported. Here, we performed comprehensive high-throughput analyses, including RNA sequencing of CR (complete remission) and relapsed AML patients, and reverse-phase protein arrays of chemoresistant cells to identify METTL3 as a key player regulating AML chemoresistance. Then, METTL3-mediated m⁶A modification was proved to induce the chemoresistance in vitro and in vivo. Furthermore, AML homing/engraftment was discovered being enhanced by upregulated-METTL3 in chemoresistant cells. And the homing/engraftment and drug-resistance associated phenotypes of chemoresistant cells could be reversed by a METTL3 inhibitor. Mechanistically, METTL3 extended the half-life of ITGA4 mRNA by m⁶A methylation, and then, increased expression of ITGA4 protein to enhance homing/engraftment of AML cells. The results provide insights into the function of m⁶A modification on the interaction between AML cells and BM niches and clarify the relationship between METTL3 and AML homing/engraftment, suggesting a therapeutic strategy for the treatment of refractory/relapsed AML with METTL3 inhibitors.

Development of a BCL-xL and BCL-2 dual degrader with improved anti-leukemic activity

PROteolysis-TArgeting Chimeras (PROTACs) have emerged as an innovative drug development platform. However, most PROTACs have been generated empirically because many determinants of PROTAC specificity and activity remain elusive. Through computational modelling of the entire NEDD8-VHL Cullin RING E3 ubiquitin ligase (CRL^VHL)/PROTAC/BCL-xL/UbcH5B(E2)-Ub/RBX1 complex, we find that this complex can only ubiquitinate the lysines in a defined band region on BCL-xL. Using this approach to guide our development of a series of ABT263-derived and VHL-recruiting PROTACs, we generate a potent BCL-xL and BCL-2 (BCL-xL/2) dual degrader with significantly improved antitumor activity against BCL-xL/2-dependent leukemia cells. Our results provide experimental evidence that the accessibility of lysines on a target protein plays an important role in determining the selectivity and potency of a PROTAC in inducing protein degradation, which may serve as a conceptual framework to guide the future development of PROTACs.

Over Fifty Years of Life, Death, and Cannibalism: A Historical Recollection of Apoptosis and Autophagy

Research in biomedical sciences has changed dramatically over the past fifty years. There is no doubt that the discovery of apoptosis and autophagy as two highly synchronized and regulated mechanisms in cellular homeostasis are among the most important discoveries in these decades. Along with the advancement in molecular biology, identifying the genetic players in apoptosis and autophagy has shed light on our understanding of their function in physiological and pathological conditions. In this review, we first describe the history of key discoveries in apoptosis with a molecular insight and continue with apoptosis pathways and their regulation. We touch upon the role of apoptosis in human health and its malfunction in several diseases. We discuss the path to the morphological and molecular discovery of autophagy. Moreover, we dive deep into the precise regulation of autophagy and recent findings from basic research to clinical applications of autophagy modulation in human health and illnesses and the available therapies for many diseases caused by impaired autophagy. We conclude with the exciting crosstalk between apoptosis and autophagy, from the early discoveries to recent findings.

Immunohistochemical Characterization of Bcl-2 in Oral Potentially Malignant Disorders

Bcl-2 is a group of apoptotic proteins that play a key role in cellular homeostasis. Overexpression of Bcl-2 has been associated with the poor prognosis of oral squamous cell carcinoma (OSCC). The aim of this study is to analyze the immunohistochemical expression of Bcl-2 in healthy oral mucosa, different oral potentially malignant disorders and OSCC, and to determine its diagnostic value. A retrospective observational study was carried out in the Oral Medicine Unit of the University of Santiago de Compostela. All the clinicopathologic data were collected and paraffin-embedded blocks were available to perform the immunohistochemistry study with Bcl-2. We studied 18 fibromas, 15 OSCC, 29 oral leukoplakia lesions (OL), 59 oral lichen planus (OLP) cases, and 16 healthy controls. OL with epithelial dysplasia (31.2%) showed the highest expression of Bcl-2 and OLP (1.9%) showed the lowest expression of Bcl-2 (P=0.025). Receiver operating characteristics curves showed that the detection of Bcl-2 enables discrimination between OL and OLPs (sensitivity: 58.6%, specificity of 99.32%). Bcl-2 negative expression in the OLP diagnosis obtained an odds ratio of 13.750 (95% confidence interval: 3.354-56.369; P<0.0001) and the positive expression in the OL 4.468 (95% confidence interval: 1.889-10.565; P=0.001). Bcl-2 could be used as a diagnostic biomarker to study their malignant transformation.

A Phase II Study of Venetoclax in Combination With Pomalidomide and Dexamethasone in Relapsed/Refractory Multiple Myeloma

BACKGROUND

Venetoclax is a selective BCL-2 inhibitor with clinical activity in relapsed/refractory multiple myeloma (RRMM). Combinations of venetoclax with agents that have complementary mechanisms of action may improve venetoclax efficacy in RRMM. This study evaluated venetoclax with pomalidomide and dexamethasone (VenPd) in RRMM.

PATIENTS AND METHODS

This phase II open label study (NCT03567616) evaluated VenPd in patients with RRMM who had received ≥ 1 prior therapy and were refractory to lenalidomide. Venetoclax was administered orally daily for days 1 to 28, pomalidomide was administered orally daily for days 1 to 21, and dexamethasone was administered weekly for each 28-day cycle. The primary objective was to characterize the safety and tolerability of VenPd. The secondary objectives were to evaluate the efficacy and pharmacokinetics. The study was terminated early due to partial clinical hold and decision to pursue biomarker driven strategy.

RESULTS

Eight patients were enrolled. Patients had a median age of 67.5 years. All patients received 400 mg venetoclax; 4 patients experienced dose-limiting toxicities and the dose was not escalated. All patients had a grade ≥ 3 adverse event, and the most common was neutropenia (n = 6); cytopenias were the most prevalent adverse events. Five patients (63%) had a confirmed response, and the median duration of response was 12.9 months. The median progression-free survival was 10.5 months.

CONCLUSIONS

Given the limited enrollment, no clear safety or efficacy conclusions about VenPd can be drawn. Preliminary safety data, particularly the occurrence of cytopenias, can be used to guide dosing strategies for future combinations of venetoclax with immunomodulatory agents.

Novel Suberoylanilide Hydroxamic Acid Analogs Inhibit Angiogenesis and Induce Apoptosis in Breast Cancer Cells

BACKGROUND

Histone deacetylases (HDACs) are the enzymes that catalyze the removal of the acetyl group from lysine residues and regulate several biological processes. Suberoylanilide hydroxamic acid (SAHA) is a notable HDAC inhibitor that exhibited remarkable anti-proliferative efficiency by alleviating gene regulation against solid and hematologic cancers.

AIM

The aim of this study was to develop new chemotherapeutic agents for breast cancer treatment, therefore, a novel series of Suberoylanilide hydroxamic acid (SAHA) analogs were investigated as anticancer agents.

METHODS

We designed and synthesized a novel series of analogs derived from SAHA by substituting alkyl, alkoxy, halo, and benzyl groups at different positions of the phenyl ring. The newly synthesized analogs were assessed for their cytotoxic potential against four human cancer cell lines in comparison with healthy cell lines, using several biological assays.

RESULTS

SAHA analogs displayed significant cytotoxic potential with IC50 values ranging from 1.6 to 19.2 µM in various tumor cell lines. Among these analogs, 2d (containing 3-chloro, 4-floro substitutions on phenyl moiety), 2h (containing 3,4-di chloro substitutions on phenyl moiety), and 2j (containing 4-chloro, 3-methyl substitutions on phenyl moiety) showed significant cytotoxic potential with IC50 values ranging from 1.6 to 1.8 µM in MCF-7 (breast carcinoma) cell line. More importantly, these analogs were found to be non-toxic towards healthy primary human hepatocytes (PHH) and mouse fibroblast cells (NIH3T3), which represent their tumor selectivity. These analogs were further analyzed for their effect on cell migration, BrdU incorporation, Annexin V-FITC and cell cycle arrest (Sub-G1 phase). Remarkably, analogs 2d, 2h, and 2j displayed significant HDAC inhibition than the parent SAHA molecule. Further studies also confirmed that these SAHA analogs are efficient in inducing apoptosis, as they regulated the expression of several proteins involved in mitochondrial or intrinsic apoptosis pathways. Findings in the Chick Chorioallantoic Membrane (CAM) assay studies revealed anti-angiogenic properties of the currently described SAHA analogs.

CONCLUSION

From anti-proliferative study results, it is clearly evident that 3,4-substitution at the SAHA phenyl ring improves the anti-proliferative activity of SAHA. Based on these findings, we presume that the synthesized novel SAHA analogs could be potential therapeutic agents in treating breast cancer.

Phase I Study of Venetoclax Plus Daratumumab and Dexamethasone, With or Without Bortezomib, in Patients With Relapsed or Refractory Multiple Myeloma With and Without t(11;14)

PURPOSE

Venetoclax is an oral BCL-2 inhibitor with single-agent activity in patients with relapsed or refractory multiple myeloma (RRMM) with t(11;14) translocation. Venetoclax efficacy in RRMM may be potentiated through combination with agents including bortezomib, dexamethasone, and daratumumab.

METHODS

This phase I study (NCT03314181) evaluated venetoclax with daratumumab and dexamethasone (VenDd) in patients with t(11;14) RRMM and VenDd with bortezomib (VenDVd) in cytogenetically unselected patients with RRMM. Primary objectives included expansion-phase dosing, safety, and overall response rate. Secondary objectives included further safety analysis, progression-free survival, duration of response, time to progression, and minimal residual disease negativity.

RESULTS

Forty-eight patients were enrolled, 24 each in parts 1 (VenDd) and 2 (VenDVd). There was one dose-limiting toxicity in part 1 (grade 3 febrile neutropenia, 800 mg VenDd). Common adverse events with VenDd and VenDVd included diarrhea (63% and 54%) and nausea (50% and 50%); grade ≥ 3 adverse events were observed in 88% in the VenDd group and 71% in the VenDVd group. One treatment-emergent death occurred in part 2 (sepsis) in the context of progressive disease, with no other infection-related deaths on study with medians of 20.9 and 20.4 months of follow-up in parts 1 and 2, respectively. The overall response rate was 96% with VenDd (all very good partial response or better [≥ VGPR]) and 92% with VenDVd (79% ≥ VGPR). The 18-month progression-free survival rate was 90.5% (95% CI, 67.0 to 97.5) with VenDd and 66.7% (95% CI, 42.5 to 82.5) with VenDVd.

CONCLUSION

VenDd and VenDVd produced a high rate of deep and durable responses in patients with RRMM. These results support continued evaluation of venetoclax with daratumumab regimens to treat RRMM, particularly in those with t(11;14).

Drimane Derivatives as the First Examples of Covalent BH3 Mimetics that Target MCL-1

Drimane sesquiterpenoid dialdehydes are natural compounds with antiproliferative properties. Nevertheless, their mode of action has not yet been discovered. Herein, we demonstrate that various drimanes are potent inhibitors of MCL-1 and BCL-xL, two proteins of the BCL-2 family that are overexpressed in various cancers, including lymphoid malignancies. Subtle changes in their structure significantly modified their activity on the target proteins. The two most active compounds are MCL-1 selective and bind in the BH3 binding groove of the protein. Complementary studies by NMR spectroscopy and mass spectrometry analyses, but also synthesis, showed that they covalently inhibit MCL-1 though the formation of a pyrrole adduct. In addition, cytotoxic assays revealed that these two compounds show a cytotoxic selectivity for BL2, a MCL-1/BCL-xL-dependent cell line and induce apoptosis.

The role of long intergenic non-coding RNA for kinase activation (LINK-A) as an oncogene in non-small cell lung carcinoma

The oncogenic role of long intergenic non-coding RNA for kinase activation (LINK-A) has been appraised in triple-negative breast cancer. However, the molecular function of LINK-A is still unclear in most cancers including lung cancer. The present study aimed to evaluate the impact of down-regulation of LINK-A in A549 and Calu-3 cell lines as cellular models of non-small cell lung carcinoma (NSCLC). We used the RNA interference system to knock down LINK-A. LINK-A expression was significantly reduced by siRNA transfection in A549 and Calu-3 cell lines. LINK-A down-regulation significantly reduced cell viability, colony-forming ability and cell migration, as measured by MTT, colony formation and invasion assays. Finally, cell cycle analysis and Annexin-V/7AAD staining indicated that apoptosis was influenced by LINK-A silencing. Taken together, LINK-A can be proposed as an oncogene in NSCLC.

In Vitro Investigation of the Cytotoxic Activity of Emodin 35 Derivative on Multiple Myeloma Cell Lines

Background

Bortezomib is used for treating multiple myeloma (MM); however, it has considerable adverse effects. Emodin has been reported to exhibit inhibitory effects on MM cell lines. We investigated the efficacy of emodin 35 (E35), an emodin derivative, using U266 and MM1s cell lines in treating MM and the efficacy of combining bortezomib and E35.

Methods

MTT assays were used to observe the effects of E35 on MM cell growth. The effects on cellular apoptosis were then observed using Annexin V/propidium iodide (PI) staining assay. The expression of apoptosis-related genes, including the caspase family, was examined. The efficacy of combining bortezomib and E35 was investigated by examining the expression of the Akt/mTOR/4EBP1 signaling pathway-related proteins.

Results

We report that E35 inhibited the growth of U266 and MM1s cells by inducing cellular apoptosis. Moreover, E35 downregulated the expression of apoptosis-related genes and suppressed the phosphorylation of Akt/mTOR/4EBP1 signaling pathway-related genes, thus exhibiting synergistic effects with bortezomib. All observed effects were dose-dependent.

Conclusion

The results showed that E35 exhibited cytotoxic effects in MM cell lines in protein levels. Thus, E35, particularly in combination with bortezomib, may be considered as a promising treatment for MM; however, this requires further investigation in vivo.

Identification of BCL-XL as highly active survival factor and promising therapeutic target in colorectal cancer

Since metastatic colorectal cancer (CRC) is a leading cause of cancer-related death, therapeutic approaches overcoming primary and acquired therapy resistance are an urgent medical need. In this study, the efficacy and toxicity of high-affinity inhibitors targeting antiapoptotic BCL-2 proteins (BCL-2, BCL-XL, and MCL-1) were evaluated. By RNA sequencing analysis of a pan-cancer cohort comprising >1500 patients and subsequent prediction of protein activity, BCL-XL was identified as the only antiapoptotic BCL-2 protein that is overactivated in CRC. Consistently, pharmacologic and genetic inhibition of BCL-XL induced apoptosis in human CRC cell lines. In a combined treatment approach, targeting BCL-XL augmented the efficacy of chemotherapy in vitro, in a murine CRC model, and in human ex vivo derived CRC tissue cultures. Collectively, these data show that targeting of BCL-XL is efficient and safe in preclinical CRC models, observations that pave the way for clinical translation.

Role of B Cell Lymphoma 2 in the Regulation of Liver Fibrosis in miR-122 Knockout Mice

MicroRNA-122 (miR-122) has been identified as a marker of various liver injuries, including hepatitis- virus-infection-, alcoholic-, and non-alcoholic steatohepatitis (NASH)-induced liver fibrosis. Here, we report that the extracellular miR-122 from hepatic cells can be delivered to hepatic stellate cells (HSCs) to modulate their proliferation and gene expression. Our published Argonaute crosslinking immunoprecipitation (Ago-CLIP) data identified several pro-fibrotic genes, including Ctgf, as miR-122 targets in mice livers. However, treating Ctgf as a therapeutic target failed to rescue the fibrosis developed in the miR-122 knockout livers. Alternatively, we compared the published datasets of human cirrhotic livers and miR-122 KO livers, which revealed upregulation of BCL2, suggesting its potential role in regulating fibrosis. Notably, ectopic miR-122 expression inhibited BCL2 expression in human HSC (LX-2) cells). Publicly available ChIP-seq data in human hepatocellular cancer (HepG2) cells and mice livers suggested miR-122 could regulate BCL2 expression indirectly through c-MYC, which was confirmed by siRNA-mediated depletion of c-MYC in Hepatocellular Carcinoma (HCC) cell lines. Importantly, Venetoclax, a potent BCL2 inhibitor approved for the treatment of leukemia, showed promising anti-fibrotic effects in miR-122 knockout mice. Collectively, our data demonstrate that miR-122 suppresses liver fibrosis and implicates anti-fibrotic potential of Venetoclax.

Molecular modulation of autophagy: New venture to target resistant cancer stem cells

Autophagy is a highly regulated catabolic process in which superfluous, damaged organelles and other cytoplasmic constituents are delivered to the lysosome for clearance and the generation of macromolecule substrates during basal or stressed conditions. Autophagy is a bimodal process with a context dependent role in the initiation and the development of cancers. For instance, autophagy provides an adaptive response to cancer stem cells to survive metabolic stresses, by influencing disease propagation via modulation of essential signaling pathways or by promoting resistance to chemotherapeutics. Autophagy has been implicated in a cross talk with apoptosis. Understanding the complex interactions provides an opportunity to improve cancer therapy and the clinical outcome for the cancer patients. In this review, we provide a comprehensive view on the current knowledge on autophagy and its role in cancer cells with a particular focus on cancer stem cell homeostasis.

Structure-Activity Relationships and Molecular Docking Analysis of Mcl-1 Targeting Renieramycin T Analogues in Patient-derived Lung Cancer Cells

Myeloid cell leukemia 1 (Mcl-1) and B-cell lymphoma 2 (Bcl-2) proteins are promising targets for cancer therapy. Here, we investigated the structure-activity relationships (SARs) and performed molecular docking analysis of renieramycin T (RT) and its analogues and identified the critical functional groups of Mcl-1 targeting. RT have a potent anti-cancer activity against several lung cancer cells and drug-resistant primary cancer cells. RT mediated apoptosis through Mcl-1 suppression and it also reduced the level of Bcl-2 in primary cells. For SAR study, five analogues of RT were synthesized and tested for their anti-cancer and Mcl-1- and Bcl-2-targeting effects. Only two of them (TM-(-)-18 and TM-(-)-4a) exerted anti-cancer activities with the loss of Mcl-1 and partly reduced Bcl-2, while the other analogues had no such effects. Specific cyanide and benzene ring parts of RT's structure were identified to be critical for its Mcl-1-targeting activity. Computational molecular docking indicated that RT, TM-(-)-18, and TM-(-)-4a bound to Mcl-1 with high affinity, whereas TM-(-)-45, a compound with a benzene ring but no cyanide for comparison, showed the lowest binding affinity. As Mcl-1 helps cancer cells evading apoptosis, these data encourage further development of RT compounds as well as the design of novel drugs for treating Mcl-1-driven cancers.

PROTACs are effective in addressing the platelet toxicity associated with BCL-XL inhibitors

BCL-X_L is an anti-apoptotic protein that plays an important role in tumorigenesis, metastasis, and intrinsic or therapy-induced cancer drug resistance. More recently, BCL-X_L has also been identified as a key survival factor in senescent cells. Accumulation of senescent cells has been indicated as a causal factor of aging and many age-related diseases and contributes to tumor relapse and metastasis. Thus, inhibition of BCL-X_L is an attractive strategy for the treatment of cancer and extension of healthspan. However, development of BCL-X_L inhibitors such as navitoclax for clinical use has been challenging because human platelets depend on BCL-X_L for survival. In this review, the authors discuss how BCL-X_L-targeted proteolysis targeting chimeras (PROTACs) afford a novel approach to mitigate the on-target thrombocytopenia associated with BCL-X_L inhibition. The authors summarize the progress in the development of BCL-X_L PROTACs. The authors highlight the in vitro and in vivo data supporting that by hijacking the ubiquitin protein ligase (E3) that are poorly expressed in human platelets, BCL-X_L PROTACs can significantly improve the therapeutic window compared to conventional BCL-X_L inhibitors. These findings demonstrated the potentially broad utility of PROTAC technology to achieve tissue selectivity through recruiting differentially expressed E3 ligases and to reduce on-target toxicity.

Venetoclax, bendamustine, and rituximab in patients with relapsed or refractory NHL: a phase Ib dose-finding study

Background

Venetoclax is a selective, potent inhibitor of the anti-apoptotic B-cell leukemia/lymphoma-2 protein approved for treatment of chronic lymphocytic leukemia. We conducted a dose-finding study of venetoclax in combination with bendamustine-rituximab (BR) in patients with relapsed/refractory non-Hodgkin's lymphoma (NHL).

Patients and methods

BR was given for six cycles at standard doses. Intermittent and continuous oral venetoclax administration was explored at 50-1200 mg daily doses. Co-primary objectives included safety, pharmacokinetics (PKs), maximum-tolerated dose (MTD), and recommended phase II dose (RP2D); secondary objective was preliminary efficacy.

Results

Sixty patients were enrolled: 32 with follicular lymphoma, 22 with diffuse large B-cell lymphoma, and 6 with marginal zone lymphoma. Nausea (70%), neutropenia (68%), diarrhea (55%), and thrombocytopenia (52%) were the most frequent adverse events (AEs). Most common grade 3/4 AEs were neutropenia (60%) and lymphopenia (38%). Serious AEs were reported in 24 patients; the most frequent were febrile neutropenia and disease progression (8% each). Five patients died from either disease progression (n = 4) or respiratory failure (n = 1). MTD was not reached; RP2D for venetoclax-BR combination was established as 800 mg daily continuously. Venetoclax PK exposure with and without BR was comparable. For all patients, overall response rate was 65%. Median duration of overall response, overall survival, and progression-free survival was 38.3 months [95% confidence interval (CI) 10.4-NR], not yet reached, and 10.7 months (95% CI 4.3-21.0), respectively.

Conclusions

This study established the safety profile of venetoclax in combination with BR, and results demonstrated tolerability and preliminary efficacy of the combination. Additional follow-up is needed to better determine the future role of BR plus venetoclax in the treatment of relapsed/refractory B-cell NHL.

Trial registered

Clinicaltrials.gov, NCT01594229.

A selective BCL-XL PROTAC degrader achieves safe and potent antitumor activity

BCL-X_L is a well-validated cancer target. However, the on-target and dose-limiting thrombocytopenia limits the use of BCL-X_L inhibitors such as ABT263 as safe and effective anticancer agents. To reduce the toxicity of ABT263, we converted it into DT2216, a BCL-X_L proteolysis targeting chimera (PROTAC), that targets BCL-X_L to the Von Hippel-Lindau (VHL) E3 ligase for degradation. We found that DT2216 was more potent against various BCL-X_L-dependent leukemia and cancer cells but significantly less toxic to platelets than ABT263 in vitro because VHL is poorly expressed in platelets. In vivo, DT2216 effectively inhibits the growth of several xenograft tumors as a single agent or in combination with other chemotherapeutic agents, without causing significant thrombocytopenia. These findings demonstrate the potential to use PROTAC technology to reduce on-target drug toxicities and rescue the therapeutic potential of previously undruggable targets. Furthermore, DT2216 may be developed as a safe first-in-class anticancer agent targeting BCL-X_L.

Denatonium Benzoate-Induces Oxidative Stress in the Heart and Kidney of Chinese Fast Yellow Chickens by Regulating Apoptosis, Autophagy, Antioxidative Activities and Bitter Taste Receptor Gene Expressions

Simple Summary

Denatonium benzoate is a strong bitter taste receptor agonist, extensively used for its activation of different cell pathways. Taste signals have been associated to food recognition and avoidance, and bitter taste provokes an aversive reaction and is assumed to protect chickens from consuming poisons and harmful toxic substances. The results of the study revealed that dietary supplementation with medium and high doses of denatonium benzoate damaged the epithelial cells of the heart and kidneys by inducing apoptosis and autophagy and reduced the growth of chickens, respectively. However, mRNA expressions of bitter taste receptors, downstream signaling effector genes, apoptosis-, autophagy- and antioxidant-related genes were higher on day 7, while these expressions were subsequently decreased on day-28 in the heart and kidney of Chinese Fast Yellow chickens in a dose-response manner.

Abstract

The sense of taste which tells us which prospective foods are nutritious, poisonous and harmful is essential for the life of the organisms. Denatonium benzoate (DB) is a bitter taste agonist known for its activation of bitter taste receptors in different cells. The aim of the current study was to investigate the mRNA expressions of bitter taste, downstream signaling effectors, apoptosis-, autophagy- and antioxidant-related genes and effector signaling pathways in the heart/kidney of chickens after DB dietary exposure. We randomly assigned 240, 1-day-old Chinese Fast Yellow chicks into four groups with five replicates of 12 chicks and studied them for 28 consecutive days. The dietary treatments consisted of basal diet and feed containing DB (5, 20 and 100 mg/kg). The results revealed that dietary DB impaired (p < 0.05) the growth performance of the chickens. Haemotoxylin and eosin staining and TUNEL assays confirmed that medium and high doses of DB damaged the epithelial cells of heart/kidney and induced apoptosis and autophagy. Remarkably, the results of RT-PCR and qRT-PCR indicated that different doses of DB gradually increased (p < 0.05) mRNA expressions of bitter taste, signaling effectors, apoptosis-, autophagy- and antioxidant- related genes on day 7 in a dose-response manner, while, these expressions were decreased (p < 0.05) subsequently by day-28 but exceptional higher (P < 0.05) expressions were observed in the high-dose DB groups of chickens. In conclusion, DB exerts adverse effects on the heart/kidney of chickens in a dose-response manner via damaging the epithelium of the heart/kidney by inducing apoptosis, autophagy associated with bitter taste and effector gene expressions. Correlation analyses for apoptosis/autophagy showed agonistic relationships. Our data provide a novel perspective for understanding the interaction of bitter taste, apoptosis, autophagy and antioxidative genes with bitter taste strong activators in the heart/kidney of chicken. These insights might help the feed industries and pave the way toward innovative directions in chicken husbandry.

Anticancer potential of NF-κB targeting apoptotic molecule "flavipin" isolated from endophytic Chaetomium globosum

BACKGROUND

Anticancer compounds from natural sources have drawn attention due to their structural diversity and relatively lesser side effects. Endophytic fungi are one such natural resource from, which plethoras of anticancerous compounds have been isolated.

PURPOSE

The objective of the study was to isolate and characterize the bioactive metabolite from Chaetomium globosum that exhibits astonishing antiproliferative activity against cancerous cell lines.

METHODS

Flavipin was isolated by bioassay-guided fractionation and identified using FT-IR, EI-MS and NMR studies. MTT assay was used to determine the cytotoxicity. Fluorescent staining (AO/EB) and DNA fragmentation studies confirmed the occurrence of apoptosis. Real time PCR and Western blotting were used to analyze the expression of apoptosis related genes and its proteins, respectively.

RESULTS

Flavipin inhibited proliferation of A549, HT-29 and MCF-7 cancer cells in dose dependent manner with an IC₅₀ concentration of 9.89 µg/ml, 18 µg/ml and 54 µg/ml, respectively, whereas it was comparatively less sensitive (IC₅₀ = 78.89 µg/ml) against normal cell line (CCD-18Co). At IC₅₀ concentration cancerous cells exhibited cell shrinkage and fragmentation of DNA, which indicated that flavipin induced apoptotic cell death. In treated cells there is an up-regulation of p53 gene and its associated protein, whereas reciprocal expression was observed in BCL-2 gene and its protein. Furthermore, western blotting results also showed down-regulation of NFκB.

CONCLUSION

This is the first report on the antiproliferative activity of flavipin isolated from endophytic C. globosum and also proposed that interaction of flavipin with NFкB could be a possible mechanism for this activity. Flavipin induced apoptosis at low concentrations in cancer cell lines (A549, HT-29) and exhibited itself as a potential anticancer agent.

Cellular demolition: Proteins as molecular players of programmed cell death

Apoptosis, a well-characterized and regulated cell death programme in eukaryotes plays a fundamental role in developing or later-life periods to dispose of unwanted cells to maintain typical tissue architecture, homeostasis in a spatiotemporal manner. This silent cellular death occurs without affecting any neighboring cells/tissue and avoids triggering of immunological response. Furthermore, diminished forms of apoptosis result in cancer and autoimmune diseases, whereas unregulated apoptosis may also lead to the development of a myriad of neurodegenerative diseases. Unraveling the mechanistic events in depth will provide new insights into understanding physiological control of apoptosis, pathological consequences of abnormal apoptosis and development of novel therapeutics for diseases. Here we provide a brief overview of molecular players of programmed cell death with discussion on the role of caspases, modifications, ubiquitylation in apoptosis, removal of the apoptotic body and its relevance to diseases.