Targeting cancer-associated fibroblast-secreted WNT2 restores dendritic cell-mediated antitumour immunity.

OBJECTIVE: Solid tumours respond poorly to immune checkpoint inhibitor (ICI) therapies. One major therapeutic obstacle is the immunosuppressive tumour microenvironment (TME). Cancer-associated fibroblasts (CAFs) are a key component of the TME and negatively regulate antitumour T-cell response. Here, we aimed to uncover the mechanism underlying CAFs-mediated tumour immune evasion and to develop novel therapeutic strategies targeting CAFs for enhancing ICI efficacy in oesophageal squamous cell carcinoma (OSCC) and colorectal cancer (CRC). DESIGN: Anti-WNT2 monoclonal antibody (mAb) was used to treat immunocompetent C57BL/6 mice bearing subcutaneously grafted mEC25 or CMT93 alone or combined with anti-programmed cell death protein 1 (PD-1), and the antitumour efficiency and immune response were assessed. CAFs-induced suppression of dendritic cell (DC)-differentiation and DC-mediated antitumour immunity were analysed by interfering with CAFs-derived WNT2, either by anti-WNT2 mAb or with short hairpin RNA-mediated knockdown. The molecular mechanism underlying CAFs-induced DC suppression was further explored by RNA-sequencing and western blot analyses. RESULTS: A negative correlation between WNT2+ CAFs and active CD8+ T cells was detected in primary OSCC tumours. Anti-WNT2 mAb significantly restored antitumour T-cell responses within tumours and enhanced the efficacy of anti-PD-1 by increasing active DC in both mouse OSCC and CRC syngeneic tumour models. Directly interfering with CAFs-derived WNT2 restored DC differentiation and DC-mediated antitumour T-cell responses. Mechanistic analyses further demonstrated that CAFs-secreted WNT2 suppresses the DC-mediated antitumour T-cell response via the SOCS3/p-JAK2/p-STAT3 signalling cascades. CONCLUSIONS: CAFs could suppress antitumour immunity through WNT2 secretion. Targeting WNT2 might enhance the ICI efficacy and represent a new anticancer immunotherapy.

GSP-2, a polysaccharide extracted from Ganoderma sinense, is a novel toll-like receptor 4 agonist.

Ganoderma sinense is a Chinese unique medicinal fungus that has been used in folk medicine for thousands of years. Polysaccharides are considered to be biologically active ingredients due to their immune-modulating functions. Previously we found that GSP-2, a new polysaccharide isolated from Ganoderma sinense, exerts an immunomodulatory effect in human peripheral blood mononuclear cells but the underlying mechanism is unclear. The present study aimed to investigate how GSP-2 triggers immunologic responses and the implicated signaling pathways. GSP-2 effects were investigated both in a macrophagic cell line, RAW264.7, and in primary macrophages. Moreover, the molecular basis of GSP-2 recognition by immune cells, and the consequent activation of signaling cascades, were explored by employing recombinant human HEK293-TLR-Blue clones, individually overexpressing various Toll-like receptors. GSP-2 dose-dependently induced the overexpression of Toll-like receptor 4 (TLR4) but did not affect the expression of other TLRs. Moreover, GSP-2 induced TNFα secretion in primary macrophages from wild-type, but not TLR4-knockout mice. In addition, GSP-2 upregulated TLR4 protein expression and activated the MAPK pathway in RAW246.7 macrophages. Finally, GSP-2 induced the production of the cytokines TNFα, IL1ß, and IL6. Our data demonstrated that GSP-2 was specifically recognized by TLR4, promoting cytokine secretion and immune modulation in macrophages.

RNase H meets molecular beacons: an ultrasensitive fluorometric assay for nucleic acids.

An innovative signal amplification strategy assisted by RNase H is described here for the detection of DNA targets in a universal fashion. A tailor-made RNA molecular beacon (RMB) conjugated with a fluorescence resonance energy transfer (FRET) pair (fluorophore and quencher) was designed, characterized, and combined with the employment of RNase H. Its performance is compared to that of other nucleases including Exonuclease III and T7 exonuclease. Fluorometry, performed best at excitation/emission wavelengths of 490/520 nm, gives an amazingly low detection limit of 23 fM for target DNA. The method was verified by the determination of human hemochromatosis (HFE) gene. It is perceived that the method represents a versatile tool for the detection of a wide range of targets. Graphical Abstract An RNase H-assisted signal amplification (RASA) method for the fluorometric assay of nucleic acids has been developed by using a unique RNA molecular beacon (RNA MB) conjugated with a fluorophore (F) and quencher (Q) pair for signal generation.

Simultaneous targeting PI3K and PERK pathways promotes cell death and improves the clinical prognosis in esophageal squamous carcinoma.

PI3K pathway is an important anti-tumor target, but its effect and mechanism is not clear in esophageal squamous cell carcinoma (ESCC). By analysis of the Cancer Genome Atlas (TCGA) datasets, we found that PI3Ks level were significantly upregulated in human esophageal cancer tissues compared with that in non-cancer tissues. The alteration of PI3K can significantly affect the overall patient survival in ESCC but not in esophageal adenocarcinoma (EAC). We found that the classic PI3K inhibitor LY294002 obviously inhibited the canonical mammalian target of rapamycin (mTOR) pathway and restrained the growth of ESCC with less toxicity to normal cells. Besides, LY294002 inhibited noncanonical PKR-like ER kinase (PERK)/elF2α/ATF4 pathway as well. Both siRNA and the small molecule inhibitor GSK2656157 against PERK/elF2α/ATF4 pathway can significantly inhibit the growth of ESCC. More importantly, GSK2656157 aggravated the inhibitory effect of LY294002 on cell growth, colony formation, and apoptosis induction of ESCC. In addition of dual high expression of PI3K and PERK pathways in the ESCC patients, the difference of overall survival (OS) was more significant than using PI3K alone. These results indicated that dual targeting of PI3K and PERK pathways might improve clinical prognosis and enhance the treatment of ESCC patients.

Dynamically Regulated CFTR Expression and Its Functional Role in Cutaneous Wound Healing.

The physiological role of cystic fibrosis transmembrane conductance regulator (CFTR) in keratinocytes and skin wound healing is completely unknown. The present study shows that CFTR is expressed in the multiple layers of keratinocytes in mouse epidermis and exhibits a dynamic expression pattern in a dorsal skin wound healing model, with diminishing levels observed from day 3 to day 5 and re-appearing from day 7 to day 10 after wounding. Knockdown of CFTR in cultured human keratinocytes promotes cell migration but inhibits differentiation, while overexpression of CFTR suppresses migration but enhances differentiation, indicating an important role of CFTR in regulating keratinocyte behavior. In addition, we have demonstrated a direct association of CFTR with epithelial junction formation as knockdown of CFTR downregulates the expression of adhesion molecules, such as E-cadherin, ZO-1 and ß-catenin, and disrupts the formation of cell junction, while overexpression of CFTR enhances cell junction formation. More importantly, we have shown that ΔF508cftr-/- mice with defective CFTR exhibit delayed wound healing as compared to wild type mice, indicating that normal function of CFTR is critical for wound repair. Taken together, the present study has revealed a previously undefined role of CFTR in regulating skin wound healing processes, which may have implications in injury repair of other epithelial tissues.

Cytotoxic dihydrothiophene-condensed chromones from the marine-derived fungus Penicillium oxalicum.

Two new dihydrothiophene-condensed chromones and a new natural chromone, namely oxalicumones A-C (1-3), respectively, were isolated from a culture broth of a marine-derived fungus, Penicillium oxalicum. The structures of 1-3 and acetylated derivatives of 1 (4-7) were elucidated on the basis of spectroscopic methods and chemical reactions. The absolute configuration of 1 and 2 were established by using the modified Mosher ester method and circular dichroism data of an in situ formed [Rh2(OCOCF3)4] and [Mo2(OAc)4] complex. (R)-MTPA ester of 1 showed cytotoxicity against A375, SW-620, and HeLa carcinoma cell lines with IC50 values of 8.9, 7.8, and 18.4 µM, respectively. Compound 1 displayed cytotoxicity against A375 and SW-620 cell lines with IC50 values of 11.7 and 22.6 µM, respectively. The structure-biological activity relationship of 1 was discussed.

Cytotoxic dihydrothiophene-condensed chromones from marine-derived fungus Penicillium oxalicum.

Two new dihydrothiophene-condensed chromones and a new natural chromone, namely oxalicumones A-C (1-3), respectively, were isolated from a culture broth of a marine-derived fungus Penicillium oxalicum SCSGAF 0023, Meripilaceae family. The structures of 1-3 and acetylated derivatives of 1 (4-7) were elucidated on the basis of spectroscopic methods and chemical reactions. The absolute configuration of 1 was established by using the modified Mosher ester method and circular dichroism data of in situ formed [Rh2(OCOCF3)4] and [Mo2(OAc)4] complexes. (R)-MTPA ester of 1 showed cytotoxicity against A375, SW-620, and HeLa carcinoma cell lines with IC50 values of 8.9, 7.8, and 18.4 µM, respectively. Compound 1 displayed cytotoxicity against A375 and SW-620 cell lines with IC50 values of 11.7 and 22.6 µM, respectively. The structure-biological activity relationship of 1 is discussed.

The selective Hsp90 inhibitor BJ-B11 exhibits potent antitumor activity via induction of cell cycle arrest, apoptosis and autophagy in Eca-109 human esophageal squamous carcinoma cells.

BJ-B11 is a selective heat shock protein 90 (Hsp90) inhibitor that has been reported to possess significant antitumor activity in multiple types of cancer cells; however, the mechanism of action needs to be further clarified. We investigated, for the first time, the antitumor activity and the molecular mechanism underlying growth inhibition in Eca-109 cells. The results revealed that BJ-B11 inhibited the proliferation of Eca-109 cells in a time- and concentration-dependent manner, with 50% inhibitory concentration (IC(50)) values of 0.31±0.01 µM after 48-h incubation. BJ-B11 induced concentration-dependent G2/M cell cycle arrest and apoptosis. The cleavage of caspase 3 and PARP signals detected might originate from mitochondrial dysfunction, which was supported by the results of reactive oxygen species (ROS) production, cytochrome c release and the mitochondrial membrane potential (MMP) reduction. The general caspase inhibitor Z-VAD-fmk did not completely abolish BJ-B11-induced cell death. Furthermore, inhibition of the Akt/mTOR/p70S6K signaling pathway might be involved in the process of BJ-B11-induced autophagy, which was characterized by the production of autophagic vacuoles and upregulation of LC3-II protein in a time- and concentration-dependent manner. Meanwhile, the general autophagy inhibitor 3-MA decreased the apoptotic ratio. Furthermore, BJ-B11 induced the polymerization of cytoskeleton ß-tubulin and F-actin. Taken together, our results suggest that the growth inhibition of Eca-109 cells induced by BJ-B11 may result from the induction of G2/M cell cycle arrest, apoptosis and autophagy.

The heat shock protein 90 inhibitor SNX-2112 inhibits B16 melanoma cell growth in vitro and in vivo.

SNX-2112 is a selective heat shock protein 90 (Hsp90) inhibitor which can exert a potent anticancer activity. In this study, we investigated the effects of SNX-2112 on B16 melanoma cells in vitro and in vivo. The 3-(4,5-dimetrylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and flow cytometric analysis demonstrated that SNX-2112 dose-dependently inhibited the growth of B16 cells, and induced G0/G1 cell cycle arrest and apoptosis. Western blotting revealed that SNX-2112 lead to the degradation of Hsp90 client proteins including Akt, IKKα, NF-κB, B-Raf and GSK3ß. Furthermore, we assessed the antitumor effect of SNX-2112 in vivo, using a xenograft model in C57BL/6 mice. Oral administration of SNX-2112 significantly inhibited the growth of B16 tumors in mice, with a 47% inhibition observed at dose of 80 mg/kg/day for 15 days, compared to control tumors. Hematoxylin-eosin (H&E) staining of xenograft tissues showed that SNX-2112 also inhibited angiogenesis and lead to a lower blood vessel density in the tumors, compared to the control group. These findings demonstrate that SNX-2112 can exhibit a potent anticancer activity against B16 melanoma cells both in vitro and in vivo, by inhibiting cell proliferation and inducing cell cycle arrest and apoptosis in a mechanism dependent on the degradation of Hsp90 client proteins.

SNX-2112, an Hsp90 inhibitor, induces apoptosis and autophagy via degradation of Hsp90 client proteins in human melanoma A-375 cells.

SNX-2112 is an Hsp90 inhibitor which is currently undergoing multiple phase 1 clinical trials; however, its mechanism of action needs to be further elaborated. Here we investigated the effects of SNX-2112 in A-375 cells. SNX-2112 induced the degradation of multiple Hsp90 client proteins, activated both the mitochondrial-mediated and death receptor-mediated apoptotic pathways, downregulated Bcl-2 and Bcl-xL, upregulated Bid, cleaved caspase-9, caspase-7, caspase-3 and PARP, and activated caspase-8. The general caspase inhibitor, z-VAD-fmk, did not completely abolish SNX-2112-induced cell death. SNX-2112 induced autophagy in a time- and dose-dependent manner via Akt/mTOR/p70S6K inhibition. SNX-2112 induces significant apoptosis and autophagy in human melanoma A-375 cells, and may be an effective targeted therapy agent.

SNX-2112, a novel Hsp90 inhibitor, induces G2/M cell cycle arrest and apoptosis in MCF-7 cells.

SNX-2112 is a heat shock protein 90 (Hsp90) inhibitor with anticancer properties currently in clinical trials. This study investigated the effects of SNX-2112 on inhibition of cell growth, the cell cycle, and apoptosis in MCF-7 human breast cancer cells, in addition to the various molecular mechanisms. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometric analysis suggest that SNX-2112 inhibits cell growth in a time- and dose-dependent manner more potently than 17-(allylamino)-17-demethoxygeldanmycin (17-AAG), a traditional Hsp90 inhibitor, probably as a result of cell-cycle arrest at the G2/M phase and the induction of apoptosis. Downregulation of Bcl-2 and Bcl-xL, upregulation of Bax, cleavage of caspase-9 and poly (ADP-ribose) polymerase (PARP), and degradation of the breast cancer-related Hsp90 client proteins human epidermal growth factor receptor-2 (HER2), Akt, Raf-1, and nuclear factor kappa-B kinase (IKK) were observed in SNX-2112 treated cells by Western blot assay. These findings suggest that the molecular mechanisms of cell-growth inhibition by SNX-2112 involve activation of the mitochondrial apoptotic pathway and the degradation of breast cancer-related proteins.

2-Amino-benzothia-zolium 2,4-dicarboxy-benzoate monohydrate.

Cocrystallization of 2-amino-benzothia-zole with benzene-1,2,4-tricarboxylic acid in a mixed solvent affords the title ternary cocrystal, C(7)H(7)N(2)S(+)·C(9)H(5)O(6) (-)·H(2)O, in which one of the carboxyl groups of the benzene-tricarboxylic acid is deproton-ated and the heterocyclic N atom of the 2-amino-benzothia-zole is protonated. In the crystal, inter-molecular N-H⋯O and O-H⋯O hydrogen-bonding inter-actions stabilize the packing.