Yaacov Ben-David

Emerging evidence indicates that tumour innervation promotes cancer progression via a non-canonical TLR7 signalling pathway. However, its impact across breast cancer subtypes, patient populations, associated molecular pathways, and oncogenic drivers remains poorly defined. We analysed TLR7 signature scores in human breast cancer across multiple datasets and evaluated their associations with prognosis, clinical outcomes, TNBC subtypes, metastasis, molecular signatures, oncogenic signalling, and pathological complete response. We demonstrate that the TLR7score signature is significantly elevated in triple-negative breast cancer (TNBC) - the most aggressive breast cancer subtype-compared with ER⁺ disease. Within TNBC, high TLR7 signalling characterises basal- and mesenchymal-like tumours relative to the luminal androgen receptor (LAR) subtype. Across multiple breast cancer cohorts, including TNBC, TLR7score alone does not uniformly predict prognosis, as both high- and low-scoring tumours are associated with reduced survival. Using sequential cut-off analysis in seven independent clinical cohorts, we show that both TLR7score-high (e.g. HR = 4.7, P = 0.01) and TLR7score-low (HR = 3.37, P = 0.038) tumours are associated with unfavourable outcomes relative to intermediate-score tumours. TLR7score-high lesions are enriched for cell proliferation, neuronal, and mast cell-related pathways, as well as RB1 and TP53 loss and elevated E2F, PI3K, MET, and MYC signalling. In contrast, TLR7score-low tumours show increased ER signalling and are enriched for T cell-associated but not neuronal pathways, delineating innervated versus non-innervated TNBC phenotypes. Moreover, TLR7score correlates with pathological complete response (pCR) in a treatment-dependent manner. Collectively, these findings suggest that TNBC progression involves both TLR7-dependent and TLR7-independent mechanisms and that TLR7score may enable patient stratification for distinct therapeutic strategies.

Introduction: 3,3′-Diindolylmethane (DIM) is a major phytochemical product derived from ingestion of cruciferous vegetables. As an effective cancer chemopreventive agent, DIM has been used in preclinical and clinical trials. Recently, our group synthesized and modified a novel DIM derivative, L1, and demonstrated its significant antileukemic activities.Methods: MTT assay was used to confirm the inhibition rates and IC₅₀ value of L1 in erythroleukemia HEL cells. Flow cytometry analysis was used to reveal cell cycle arrest and apoptosis. RNAseq data with KEGG pathway enrichment analysis was performed to predict the anticancer mechanism of L1. RT-qPCR and Western blotting were carried out to verify the mechanism in the ER stress-mediated apoptosis and FLI1/AKT pathway. FLI1 knockdown in HEL cells was performed to confirm the mechanism of L1 in the FLI1/AKT pathway. AutoDocking analysis and PPI analysis via the STRING database were used to discover the potential target of L1. HSPA1A knockdown and treatment with HSP70 inhibitor were used to further evaluate the L1 target.Results: L1 significantly inhibited the growth of erythroleukemia HEL cells, with an IC₅₀ value of 1.15 ± 0.03 µM L1 induced G2/M cell cycle arrest and cell apoptosis. RNA sequencing analysis revealed that differentially expressed genes (DEGs) mainly enriched in protein processing of endoplasmic reticulum (ER). L1 increased the protein expression level of GRP78 (BIP) and the RNA transcription of XBP1 and DDIT3 to induce ER stress-mediated apoptosis. Meanwhile, PPI analysis suggested that HSP70 (HSPA1A and HSPA1B) is a pivotal gene that may be involved in the ER stress. AutoDocking analysis also revealed that L1 may bind to the HSP70 protein (HSPA1A and HSPA1B). The apoptosis rate was reduced by cotreatment of L1 and the Hsp70 inhibitor VER155008. Moreover,the inhibition rate was decreased in the HSPA1A knockdown HEL cells, suggesting that L1-induced apoptosis was related to HSP70 activity. Moreover, FLI1 is a crucial target for mediating cell differentiation, apoptosis, inflammation and displays abnormal expression in HEL cells. Here, we showed that the protein expression levels of FLI1 and AKT/p-AKT decreased with L1 treatment and that the RNA expressions of their downstream genes GATA1, TFRC, GYPA, CDKN1A and CDKN1B were also regulated by L1.Conclusion: This study revealed that the DIM-derivative molecule, L1, induced ER stress-mediated apoptosis and suppressed cell growth by inhibiting the FLI1/AKT pathway in erythroleukemia HEL cells.

The retinoblastoma tumor suppressor pRB is required for skeletal myogenesis but its role in maintenance of post-mitotic skeletal muscle and the contribution, if any, of its relatives, p107 and p130, are largely unknown. Here, we show that targeted deletion of murine Rb in proliferating myoblasts during myogenesis, using a Pax7-Cre deleter line, leads to muscle fiber degeneration, short myotubes with elongated, large nuclei, reduced late muscle marker expression, and fetal death. These defects are recapitulated in primary myoblasts derived from Pax7-Cre:Rb^f/f mice, can be ameliorated by inhibition of autophagy in vitro, and are exacerbated in Pax7-Cre:Rb^f/f:p107^–/– but not Pax7-Cre:Rb^f/f:p130^–/– double mutant fetuses. In contrast, deletion of Rb on a wildtype or p107^–/– background in post-mitotic muscle, via an Mlc_1f-Cre deleter line, has no apparent impact on skeletal muscle homeostasis. However, approximately 10% of Mlc_1f-Cre:Rb^f/f:p130^–/– mice, with combined deletion of Rb and p130, exhibit reduced size, wobbly, waddling gait, along with muscle degeneration and dramatic reduction in skeletal muscle mass. The remaining Mlc_1f-Cre:Rb^f/f:p130^–/– mice had near normal posture and muscle mass, but certain muscle areas show extensive central nuclei, while whole muscles express elevated levels of Pax7 and autophagic markers, suggestive of excessive muscle degeneration and regeneration. These mice also display muscle fiber type redistribution accompanied by reduced PGC-1α expression. Thus, continuous pRB and p130 expression is required to maintain skeletal muscle homeostasis and prevent adult muscle degeneration. Moreover, genetic modifiers—yet to be defined—affect the balance between muscle atrophy and regeneration.

Introducing Bruton’s tyrosine kinase (BTK) inhibitors has significantly improved outcomes for patients with B-cell malignancies and autoimmune disorders. However, resistance, either primary or acquired, remains a major clinical challenge. To better understand the underlying resistance mechanisms to BTK inhibitors, we established an ibrutinib-resistant model from a patient-derived splenic marginal zone lymphoma (MZL) cell line (VL51) through prolonged drug exposure. Resistant cells exhibited a 15-fold increase in ibrutinib’s IC50, along with distinct morphological changes, mitochondrial activation, and cross-resistance to covalent, non-covalent BTK inhibitors and BTK degraders. Integrated transcriptomic, epigenomic, and proteomic analyses identified overexpression and secretion of IL-16 as a key feature of resistance, driven by chromatin remodeling and activation of the FLI1 transcription factor. IL-16 conferred ibrutinib resistance via CD9-mediated activation of the NF-κB and AKT signaling pathways and was found to be elevated in the serum of ibrutinib-refractory CLL patients. Functional studies showed that targeting the IL-16/CD9 axis using neutralizing antibodies or CD9-binding peptides restored sensitivity to BTK inhibitors and R-CHOP chemotherapy in MZL, mantle cell lymphoma, and diffuse large B-cell lymphoma models. These findings reveal a novel, targetable resistance mechanism with potential therapeutic implications for overcoming BTK inhibitor resistance in B-cell lymphomas.

Vitamin D3 (VD3) and its active form calcitriol (Ca) exhibit anti-neoplastic activity against several types of cancer, although the underlying mechanism is not fully understood. Herein, we tested the effects of VD3 and Ca on erythro-leukemogenesis and investigated the underlying mechanism. VD3 and Ca treatment strongly inhibited cancer progression in a mouse model of erythroleukemia induced by the Friend virus. In tissue culture, VD3 and Ca inhibited proliferation of leukemic cell lines. Growth inhibition was associated with induction of G1 phase cell cycle arrest and apoptosis. Transcription of the VD3 receptor, VDR, is strongly induced by Ca, but not VDR. However, leukemia growth suppression by both VD3 and Ca is shown to be independent of VDR. In leukemic cells, both VD3 and Ca induced genes associated with metabolic pathways. Both VD3 and Ca induce the cytosolic glutathione degradase CHAC1 through activation of the ER stress response pathway ATF3/ATF4/CHOP genes. Higher expression of CHAC1 also suppressed the oncogene NOTCH1. Accordingly, knockdown of CHAC1 antagonized the inhibitory effect of VD3 and Ca on leukemic growth leading to higher NOTCH1 expression. Conversely, overexpression of CHAC1 suppressed leukemia cell growth and inhibited the expression of NOTCH1. Additionally, glutathione antagonized leukemia cell suppression induced by VD3 and Ca, demonstrating that this vitamin inhibits the proliferation of leukemic cells via CHAC1. Taken together, our results demonstrated that VD3 and Ca can prolong the survival of leukemia mice and inhibit the proliferation of erythroleukemia cell HEL through CHAC1 or CHAC1-mediated NOTCH1 inhibition.

Background: Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease, characterized by hepatic lipid accumulation. The Fufangduzhong formula (FFDZ) is a traditional Chinese medicine (TCM) formulation composed of Eucommia ulmoides Oliv., Leonurus artemisia (Lour.) S. Y. Hu, Prunella vulgaris Linn, Uncariarhynchophylla (Miq.) Miq. ex Havil., and Scutellaria baicalensis Georgi. It has demonstrated hepatoprotective effects and the ability to reduce lipid accumulation. However, its mechanisms against NAFLD remain unclear.Methods: UPLC-MS/MS was used to identify FFDZ metabolites. C57BL/6J mice were fed a high-fat diet (HFD) supplemented with or without FFDZ (HFD+L, 0.45 g/kg/d; HFD+H, 0.9 g/kg/d) for 12 weeks. Biochemical indicators and histopathological observations were utilized to assess the extent of metabolic homeostasis disorder and hepatic steatosis. An analysis of differentially expressed genes and regulated signaling pathways was conducted using hepatic transcriptomics. Metabolomics analysis was performed to investigate the significantly changed endogenous metabolites associated with NAFLD in mice serum using UPLC-Q-TOF/MS. Western blot was employed to detect proteins involved in the lipid metabolism-related signaling pathways. Oleic acid-induced hepatic steatosis was used to examine the lipid-lowering effect of FFDZ-containing serum in vitro.Results: A total of eight active metabolites were identified from the FFDZ formula and FFDZ-containing serum through UPLC-MS/MS analysis. FFDZ reduced body weight, liver weight, and levels of inflammatory cytokines, and it ameliorated hepatic steatosis, serum lipid profiles, insulin sensitivity, and glucose tolerance in mice with HFD-induced NAFLD. Transcriptomics revealed that FFDZ modulated the lipid metabolism-related pathways, including the PPAR signaling pathway, Fatty acid metabolism, and AMPK signaling pathway. Meanwhile, Western blot analysis indicated that FFDZ downregulated the expression of lipid synthesis-related proteins (Srebp-1c, Acly, Scd-1, Fasn, Acaca, and Cd36) and upregulated the fatty acid oxidation-related proteins (p-Ampk, Ppar-α, and Cpt-1). Furthermore, metabolomics identified FFDZ-mediated reversal of phospholipid dysregulation (PC, PE, LPC, LPE). Additionally, FFDZ-containing serum remarkedly reduced OA-induced lipid accumulation in HepG2 cells.Conclusion: The present results demonstrate that FFDZ exerts anti-NAFLD effects by enhancing glucose tolerance and insulin sensitivity, as well as regulating the Ampk signaling pathway to ameliorate lipid metabolism disorder, lipotoxicity, hepatic steatosis, and inflammatory responses.

Plaque Psoriasis: Plaque psoriasis is an inflammatory skin disorder affecting nearly 2% of the world population. Despite recent advances in psoriasis treatment, there is still a need for more effective therapies. The ETS transcription factor FLI1 plays critical roles in hematopoiesis, angiogenesis, immunity, and cancer. Emerging evidence suggests that FLI1 is intricately involved in inflammatory processes underlying psoriasis pathogenesis. Methods: RNAseq and bioinformatic analysis were used to identify the correlation between FLI1 levels and the expression of inflammatory genes associated with psoriasis. Over-expression of FLI1 in skin cells determined FLI1’s role in inducing transcription of psoriasis-related inflammatory genes, including IL6, IL1A, IL1B, IL23, and TNFα. Inhibitors such as chelerythrine (CLT) were tested for their suppressive effects on these genes. Mouse models of plaque psoriasis were employed to assess the therapeutic potential of CLT and tacrolimus (TAC). Results: Over-expression of FLI1 in skin cells upregulated 24 psoriasis-associated genes, which were identified through RNAseq. Inhibitors of FLI1, such as CLT, suppressed these inflammatory genes in skin cells. In mouse models of plaque psoriasis induced by imiquimod (IMQ) or phorbol ester (TPA), treatment with the anti-FLI1 inhibitor CLT, administered either peritoneally or topically, significantly downregulated inflammatory genes and alleviated psoriasis symptoms. Similarly, TAC, a common immunosuppressive agent, effectively attenuated IMQ-induced psoriasis by acting as a potent anti-FLI1 compound. Conclusion: These findings demonstrate that FLI1 plays a central role in psoriasis development and highlight it as a potential therapeutic target for this skin disorder.