CircRNA HLCS regulates lens epithelial cell apoptosis via miR-338-3p/BPNT1 axis.

PURPOSE: The purpose of this study was to investigate the effect of circ_HLCS on age-related cataract (ARC). METHODS: Circ_HLCS, microRNA (miR)-338-3p, and bisphosphate 3'-nucleotidase 1 (BPNT1) were quantified by quantitative real-time polymerase chain reaction or western blot. Cell proliferation and cell viability were assessed by the 5-Ethynyl-2'-deoxyuridinr and cell counting kit-8 assays. Cell apoptosis was detected by flow cytometry. Targeted correlations among circ_HLCS, miR-338-3p, and BPNT1 were verified by the dual-luciferase reporter and RNA pull-down assays. RESULTS: circ_HLCS was diminished in ARC tissues and UV-treated SRA01/04 cells. Elevated content of circ_HLCS undermined UV-induced cell proliferation inhibition and apoptosis. Mechanistically, circ_HLCS directly targeted miR-338-3p, and circ_HLCS regulated BPNT1 expression through miR-338-3p. Furthermore, reduction of miR-338-3p ameliorated UV-induced SRA01/04 cell damage by increasing BPNT1 expression. CONCLUSION: Taken together, these data suggested that circ_HLCS inhibited apoptosis of UV-treated SRA01/04 cells by miR-338-3p/BPNT1 axis. Therefore, circ_HLCS might be a potential therapeutic target for ARC.

Single protein encapsulated SN38 for tumor-targeting treatment.

BACKGROUND: The alkaloid camptothecin analog SN38 is a potent antineoplastic agent, but cannot be used directly for clinical application due to its poor water solubility. Currently, the prodrug approach on SN38 has resulted in 3 FDA-approved cancer therapeutics, irinotecan, ONIVYDE, and Trodelvy. However, only 2-8% of irinotecan can be transformed enzymatically in vivo into the active metabolite SN38, which severely limits the drug's efficacy. While numerous drug delivery systems have been attempted to achieve effective SN38 delivery, none have produced drug products with antitumor efficacy better than irinotecan in clinical trials. Therefore, novel approaches are urgently needed for effectively delivering SN38 to cancer cells with better efficacy and lower toxicity. METHODS: Based on the unique properties of human serum albumin (HSA), we have developed a novel single protein encapsulation (SPE) technology to formulate cancer therapeutics for improving their pharmacokinetics (PK) and antitumor efficacy and reducing their side effects. Previous application of SPE technology to doxorubicin (DOX) formulation has led to a promising drug candidate SPEDOX-6 (FDA IND #, 152154), which will undergo a human phase I clinical trial. Using the same SPE platform on SN38, we have now produced two SPESN38 complexes, SPESN38-5 and SPESN38-8. We conducted their pharmacological evaluations with respect to maximum tolerated dose, PK, and in vivo efficacy against colorectal cancer (CRC) and soft tissue sarcoma (STS) in mouse models. RESULTS: The lyophilized SPESN38 complexes can dissolve in aqueous media to form clear and stable solutions. Maximum tolerated dose (MTD) of SPESN38-5 is 250 mg/kg by oral route (PO) and 55 mg/kg by intravenous route (IV) in CD-1 mice. SPESN38-8 has the MTD of 45 mg/kg by IV in the same mouse model. PK of SPESN38-5 by PO at 250 mg/kg gave mouse plasma AUC0-∞ of 0.05 and 4.5 nmol × h/mL for SN38 and SN38 glucuronidate (SN38G), respectively, with a surprisingly high molar ratio of SN38G:SN38 = 90:1. However, PK of SPESN38-5 by IV at 55 mg/kg yielded much higher mouse plasma AUC0-∞ of 19 and 28 nmol × h/mL for SN38 and SN38G, producing a much lower molar ratio of SN38G:SN38 = 1.5:1. Antitumor efficacy of SPESN38-5 and irinotecan (control) was evaluated against HCT-116 CRC xenograft tumors. The data indicates that SPESN38-5 by IV at 55 mg/kg is more effective in suppressing HCT-116 tumor growth with lower systemic toxicity compared to irinotecan at 50 mg/kg. Additionally, SPESN38-8 and DOX (control) by IV were evaluated in the SK-LMS-1 STS mouse model. The results show that SPESN38-8 at 33 mg/kg is highly effective for inhibiting SK-LMS-1 tumor growth with low toxicity, in contrast to DOX's insensitivity to SK-LMS-1 with high toxicity. CONCLUSION: SPESN38 complexes provide a water soluble SN38 formulation. SPESN38-5 and SPESN38-8 demonstrate better PK values, lower toxicity, and superior antitumor efficacy in mouse models, compared with irinotecan and DOX.

Structure-Activity Relationship of FL118 Platform Position 7 Versus Position 9-Derived Compounds and Their Mechanism of Action and Antitumor Activity.

Structurally, FL118 is a camptothecin analogue and possesses exceptional antitumor efficacy against human cancer through a novel mechanism of action (MOA). In this report, we have synthesized and characterized 24 FL118 Position 7-substituted and 24 FL118 Position 9-substituted derivatives. The top compounds were further characterized for their MOA in colorectal cancer (CRC) models using CRC patient-derived xenograft (PDX) models and pancreatic cancer PDX models to evaluate their antitumor activities. Four FL118 Position 7-substituted derivatives showed significantly better antitumor efficacy than the FL118 Position 9-substituted derivatives. The four identified compounds also appeared to have better antitumor activity than their parental platform FL118. Interestingly, RNA-Seq analyses indicated that three of the four compounds exerted antitumor effects via an MOA similar to FL118, which provided an intriguing opportunity for follow-up studies. Extended in vivo studies revealed that FL77-6 (7-(4-ethylphenyl)-FL118), FL77-9 (7-(4-methoxylphenyl)-FL118), and FL77-24 (7-(3, 5-dimethoxyphenyl)-FL118) exhibit potential for further development toward clinical trials.

Role of the DEAD-box RNA helicase DDX5 (p68) in cancer DNA repair, immune suppression, cancer metabolic control, virus infection promotion, and human microbiome (microbiota) negative influence.

There is increasing evidence indicating the significant role of DDX5 (also called p68), acting as a master regulator and a potential biomarker and target, in tumorigenesis, proliferation, metastasis and treatment resistance for cancer therapy. However, DDX5 has also been reported to act as an oncosuppressor. These seemingly contradictory observations can be reconciled by DDX5's role in DNA repair. This is because cancer cell apoptosis and malignant transformation can represent the two possible outcomes of a single process regulated by DDX5, reflecting different intensity of DNA damage. Thus, targeting DDX5 could potentially shift cancer cells from a growth-arrested state (necessary for DNA repair) to apoptosis and cell killing. In addition to the increasingly recognized role of DDX5 in global genome stability surveillance and DNA damage repair, DDX5 has been implicated in multiple oncogenic signaling pathways. DDX5 appears to utilize distinct signaling cascades via interactions with unique proteins in different types of tissues/cells to elicit opposing roles (e.g., smooth muscle cells versus cancer cells). Such unique features make DDX5 an intriguing therapeutic target for the treatment of human cancers, with limited low toxicity to normal tissues. In this review, we discuss the multifaceted functions of DDX5 in DNA repair in cancer, immune suppression, oncogenic metabolic rewiring, virus infection promotion, and negative impact on the human microbiome (microbiota). We also provide new data showing that FL118, a molecular glue DDX5 degrader, selectively works against current treatment-resistant prostate cancer organoids/cells. Altogether, current studies demonstrate that DDX5 may represent a unique oncotarget for effectively conquering cancer with minimal toxicity to normal tissues.

Palmitic acid promotes human retinal pigment epithelial cells migration by upregulating miR-222 expression and inhibiting NUMB.

High glucose promotes retinal pigment epithelial cell (RPEC) migration. However, the underlying molecular mechanisms explaining how high fatty acid levels affect RPEC migration remain largely unknown. We investigated whether and how palmitic acid (PA) impacts the migration of human RPEC cell line ARPE-19. ARPE-19 cells were treated with varying doses of palmitic acid, and the RPEC migration was evaluated by scratch and transwell migration assays. Cell viability was determined by the CCK-8 method. The levels of epithelial-mesenchymal transition (EMT)-associated proteins, including E-cadherin, vimentin, MMP2, and MMP3, were evaluated by western blot. The microRNAs and mRNAs levels were assessed by quantitative PCR. miRNA targets were predicted with online tools and validated with the luciferase reporter assay. miRNA mimics, inhibitors, and siRNA oligos were used to perform gain-of-function and loss-of-function studies. We found that PA increased viability of ARPE-19 cells, promoted their migration and EMT. PA decreased E-cadherin protein expression, and increased vimentin, MMP2, and MMP3 protein levels. Additionally, PA increased miR-222 expression in ARPE-19 cells, and functionally blocking miR-222 suppressed the PA-induced RPEC migration and EMT. NUMB was identified as a downstream target of miR-222, and NUMB knockdown abolished the effects of PA on promoting the migration and EMT of ARPE-19 cells. Therefore, PA promotes human RPEC migration by upregulating miR-222 expression and downregulating NUMB. This study unravels a novel PA-miR-222-NUMB axis that can be potentially targeted for therapy of high fat acid-related ocular diseases.

Single Protein Encapsulated SN38 for Tumor-Targeting Treatment.

Background: The alkaloid camptothecin analog SN38 is a potent antineoplastic agent, but cannot be used directly for clinical application due to its poor water solubility. Currently, the prodrug approach on SN38 has resulted in 3 FDA-approved cancer therapeutics, irinotecan, ONIVYDE, and Trodelvy. However, only 2-8% of irinotecan can be transformed enzymatically in vivo into the active metabolite SN38, which severely limits the drug's efficacy. While numerous drug delivery systems have been attempted to achieve effective SN38 delivery, none have produced drug products with antitumor efficacy better than irinotecan in clinical trials. Therefore, novel approaches are urgently needed for effectively delivering SN38 to cancer cells with better efficacy and lower toxicity. Methods: Based on the unique properties of human serum albumin (HSA), we have developed a novel single protein encapsulation (SPE) technology to formulate cancer therapeutics for improving their pharmacokinetics (PK) and antitumor efficacy and reducing their side effects. Previous application of SPE technology to doxorubicin (DOX) formulation has led to a promising drug candidate SPEDOX-6 (FDA IND #, 152154), which will undergo a human phase I clinical trial. Using the same SPE platform on SN38, we have now produced two SPESN38 complexes, SPESN38-5 and SPESN38-8. We conducted their pharmacological evaluations with respect to maximum tolerated dose, PK, and in vivo efficacy against colorectal cancer (CRC) and soft tissue sarcoma (STS) in mouse models. Results: The lyophilized SPESN38 complexes can dissolve in aqueous media to form clear and stable solutions. Maximum tolerated dose (MTD) of SPESN38-5 is 250 mg/kg by oral route (PO) and 55 mg/kg by intravenous route (IV) in CD-1 mice. SPESN38-8 has the MTD of 45 mg/kg by IV in the same mouse model. PK of SPESN38-5 by PO at 250 mg/kg gave mouse plasma AUC0-∞ of 0.0548 and 4.5007 (nmol × h/mL) for SN38 and SN38 glucuronidate (SN38G), respectively, with a surprisingly high molar ratio of SN38G:SN38 = 82:1. However, PK of SPESN38-5 by IV at 55 mg/kg yielded much higher mouse plasma AUC0-∞ of 18.80 and 27.78 nmol × h/mL for SN38 and SN38G, producing a much lower molar ratio of SN38G:SN38 = 1.48:1. Antitumor efficacy of SPESN38-5 and irinotecan (control) was evaluated against HCT-116 CRC xenograft tumors. The data indicates that SPESN38-5 by IV at 55 mg/kg is more effective in suppressing HCT-116 tumor growth with lower systemic toxicity compared to irinotecan at 50 mg/kg. Additionally, SPESN38-8 and DOX (control) by IV were evaluated in the SK-LMS-1 STS mouse model. The results show that SPESN38-8 at 33 mg/kg is highly effective for inhibiting SK-LMS-1 tumor growth with low toxicity, in contrast to DOX's insensitivity to SK-LMS-1 with high toxicity. Conclusion: SPESN38 complexes provide a water soluble SN38 formulation. SPESN38-5 and SPESN38-8 demonstrate better PK values, lower toxicity, and superior antitumor efficacy in mouse models, compared with irinotecan and DOX.

Allyl-isothiocyanate against colorectal cancer via the mutual dependent regulation of p21 and Nrf2.

Allyl-isothiocyanate (AITC) is a common Isothiocyanates (ITC) and its chemo-preventive and anti-tumor effects are believed to be related to the activation of NF-E2 p45-related Factor 2 (Nrf2). However, its anti-tumor effects on colorectal cancer (CRC) are not well elucidated. Here, we investigated the therapeutic in vitro and/or in vivo effects and mechanisms of action (MOA) for AITC on CRC cell line HCT116 (human) and MC38 (mouse). AITC treatment in a low concentration range (1 mg/kg in vivo) significantly inhibited the tumor cell growth and increased the expression of p21 and Nrf2. The AITC-mediated induction of p21 was dependent on Nrf2 but independent on p53 in vitro and in vivo at low dose. In contrast, the high dose of AITC (5 mg/kg in vivo) failed to increase substantial levels of p21/MdmX, and impaired the total antioxidant capacity of tumors and subsequent anti-tumor effect in vivo. These results suggest that an optimal dose of AITC is important and required for the proper Nrf2 activation and its anti-CRC effects and thus, providing insights into the potential applications of AITC for the prevention and treatment of CRC.

Sensitive N-Glycopeptide Profiling of Single and Rare Cells Using an Isobaric Labeling Strategy without Enrichment.

Single-cell omics is critical in revealing population heterogeneity, discovering unique features of individual cells, and identifying minority subpopulations of interest. As one of the major post-translational modifications, protein N-glycosylation plays crucial roles in various important biological processes. Elucidation of the variation in N-glycosylation patterns at single-cell resolution may largely facilitate the understanding of their key roles in the tumor microenvironment and immune therapy. However, comprehensive N-glycoproteome profiling for single cells has not been achieved due to the extremely limited sample amount and incompatibility with the available enrichment strategies. Here, we have developed an isobaric labeling-based carrier strategy for highly sensitive intact N-glycopeptide profiling for single cells or a small number of rare cells without enrichment. Isobaric labeling has unique multiplexing properties, by which the "total" signal from all channels triggers MS/MS fragmentation for N-glycopeptide identification, while the reporter ions provide quantitative information. In our strategy, a carrier channel using N-glycopeptides obtained from bulk-cell samples significantly improved the "total" signal of N-glycopeptides and, therefore, promoted the first quantitative analysis of averagely 260 N-glycopeptides from single HeLa cells. We further applied this strategy to study the regional heterogeneity of N-glycosylation of microglia in mouse brain and discovered region-specific N-glycoproteome patterns and cell subtypes. In conclusion, the glycocarrier strategy provides an attractive solution for sensitive and quantitative N-glycopeptide profiling of single/rare cells that cannot be enriched by traditional workflows.

Somatic variants of MAP3K3 are sufficient to cause cerebral and spinal cord cavernous malformations.

Cerebral cavernous malformations (CCMs) and spinal cord cavernous malformations (SCCMs) are common vascular abnormalities of the CNS that can lead to seizure, haemorrhage and other neurological deficits. Approximately 85% of patients present with sporadic (versus congenital) CCMs. Somatic mutations in MAP3K3 and PIK3CA were recently reported in patients with sporadic CCM, yet it remains unknown whether MAP3K3 mutation is sufficient to induce CCMs. Here we analysed whole-exome sequencing data for patients with CCM and found that ∼40% of them have a single, specific MAP3K3 mutation [c.1323C>G (p.Ile441Met)] but not any other known mutations in CCM-related genes. We developed a mouse model of CCM with MAP3K3I441M uniquely expressed in the endothelium of the CNS. We detected pathological phenotypes similar to those found in patients with MAP3K3I441M. The combination of in vivo imaging and genetic labelling revealed that CCMs were initiated with endothelial expansion followed by disruption of the blood-brain barrier. Experiments with our MAP3K3I441M mouse model demonstrated that CCM can be alleviated by treatment with rapamycin, the mTOR inhibitor. CCM pathogenesis has usually been attributed to acquisition of two or three distinct genetic mutations involving the genes CCM1/2/3 and/or PIK3CA. However, our results demonstrate that a single genetic hit is sufficient to cause CCMs.

ß-asarone attenuates the proliferation, migration and enhances apoptosis of retinoblastoma through Wnt/ß-catenin signaling pathway.

PURPOSE: ß-asarone is the prime component of essential oil extracted from Acori graminei Rhizoma, which plays an inhibitory role in various tumors. Here, we aim to investigate the functions as well as the mechanism of ß-asarone in retinoblastoma (RB). METHODS: RB cell lines SO-Rb50 and HXO-Rb44 were treated with different doses of ß-asarone. Then, CCK8 and BrdU experiments were adopted to examine the RB cell proliferation. Wound healing test and Transwell assay were employed to detect cell migration and invasion. RB cell apoptosis was tested by flow cytometry and Western blot. An RB cell xenograft model was constructed on nude mice for testing the role of ß-asarone on RB cell growth in vivo. RT-PCR and Western blot were used to determine the effect of ß-asarone on Wnt/ß-catenin signaling pathway. Furthermore, the Wnt/ß-catenin pathway inhibitor PNU-74654 and activator HLY78 were administered to RB cells for confirming the effects of ß-asarone in Wnt/ß-catenin pathway. RESULTS: In vivo experiment showed that ß-asarone attenuated SO-Rb50 cell growth in nude mice. Further research found that ß-asarone significantly repressed Wnt/ß-catenin canonical pathway activation. CONCLUSION: Prior inhibition of Wnt/ß-catenin pathway abolished the antitumor effects induced by ß-asarone. ß-asarone exerted antitumor effects in RB cells by inactivating the Wnt/ß-catenin signaling pathway.

Fluorescein-labeled ThUBD probe for super-sensitive visualization of polyubiquitination signal in situ cells.

Ubiquitin-binding domains (UBDs) are modular elements that bind non-covalently to the ubiquitin and ubiquitin chains. The preferences of UBDs for ubiquitin chains of specific length and linkage are central to their functions. We demonstrated that an artificial tandem hybrid UBD (ThUBD) exhibits an unbiased high affinity to all ubiquitin chains and is a promising tool for global ubiquitination profiling research. In this study, we labeled fluorescein on the four cysteine residues in the N-terminal glutathione S-transferase (GST) tag of ThUBD, generating a fluorescein-labeled ThUBD (ThUBD-Flu) probe for direct polyubiquitination signal imaging and visualization. Compared to the canonical ubiquitin antibody method, the ThUBD-Flu is hyper-sensitive and accurate to detect ubiquitination signal. More importantly, the ThUBD-Flu probe provided, for the first time, a widely applicable, super-sensitive and unbiased technique for in situ detection of intracellular polyubiquitination signal through immunofluorescence staining, which was only achievable with recombinant fluorescence tag fused ubiquitin gene previously. We propose that ThUBD-Flu, combined with evolving microscopy technology, could serve as prototypes to track and trace cellular polyubiquitination signal in vivo.

Resource utilization of pig hair to prepare low-cost adsorbents with high density of sulfhydryl for enhanced and trace level removal of aqueous Hg(II).

Pig hair (PH), a keratinous waste, was modified by ammonium thioglycolate in a ball milling to promote its performance of Hg(II) sequestration. The ball milling broke the hydrophobic cuticle sheath and enhanced the reduction of disulfide bond, which increased the sulfydryl content of the modified PH (BTPH) from 0.07 to 11.05 µmol/g. BTPH exhibited a significantly higher capture capacity of Hg(II) (415.4 mg/g) than PH (3.1 mg/g), as well as the commercial activated carbon (219.7 mg/g), and persisted its performance over a wide range of solution pH. Meanwhile, BTPH with a distribution coefficient of 5.703 × 105 mL/g could selectively capture Hg(II) from the water with the coexisting metal ions such as Mg(II), Cd(II) and Pb(II). Moreover, the low-cost BTPH could reduce the Hg(II) from 1.0 mg/L to well below the limit of drinkable water (2 µg/L) in real-world samples. Density functional theory (DFT) calculations and state-of-the-art characterizations illustrated that the binding of Hg(II) to sulfydryl groups was the main adsorption mechanism. Notably, BTPH decreased the mercury content of water spinaches from 24.1 to 0.50 mg/kg and thereby significantly reduced the phytotoxicity of Hg(II). This work therefore provides a sustainable way to utilize keratinous wastes for the remediation of aqueous Hg(II).

Factors associated with left ventricular diastolic dysfunction in patients with septic shock.

PURPOSE: To investigate risk factors associated with left ventricular diastolic dysfunction (LVDD) of patients with septic shock. MATERIALS AND METHODS: Patients with septic shock concomitant with or without LVDD were retrospectively enrolled and divided into the LVDD group (n = 17) and control without LVDD (n = 85). The clinical and ultrasound data were analyzed. RESULTS: A significant (P < 0.05) difference existed between the two groups in serum creatinine, APACHE II score, serum glucose, triglyceride, BUN, FT4, LAVI, mitral E, average e', E/average e', septal e', septal e'/septal s', E/septal e', lateral s', lateral e', and E/lateral e'. LAVI > 37 mL/m2, septal e' < 7 cm/s (OR 11.04, 95% CI 3.38-36.05), septal e'/septal s' < 0.8 (OR 4.09, 95% CI 1.37-12.25), E/septal e' > 15 (OR 22.86, 95% CI 6.09-85.79), lateral e' < 8 cm/s (OR 9.16, 95% CI 2.70-31.07), E/lateral e' > 13 (OR 52, 95% CI 11.99- 225.55), lateral s' < 10 (OR 3.36, 95% CI 1.13-9.99), average e' > 10, E/average e' > 10 (OR 9.53, 95% CI 2.49-36.46), APACHE II score > 16 (OR 3.33, 95% CI 1.00-11.03), SOFA > 5 (or 3.43, 95% CI 1.11-10.60), BUN > 12 mmol/L (OR 3.37, 95% CI 1.15-9.87), serum creatinine > 146 µmol/L (OR 5.08, 95% CI 1.69-15.23), serum glucose > 8 mmol/L (OR 3.36, 95% CI 1.09-10.40), and triglyceride > 1.8 mmol/L were significant (P < 0.05) risk factors for LVDD. LAVI > 37 ml/m2, lateral e' < 8 cm/s, E/lateral e' > 13, and SOFA > 5 were significant (P < 0.05) independent risk factors for LVDD. ROC curve analysis demonstrated that the cut-off value and AUC were 37.09 mL/m2 and 0.85 for LAVI, 8.00 cm/s and 0.89 for lateral e', 12.86 and 0.82 for E/lateral e', and 5.00 and 0.69 for SOFA, respectively. CONCLUSION: Left atrial volume index, mitral lateral e', E/lateral e', and SOFA score are significant independent risk factors for predicting left ventricular diastolic dysfunction in patients with septic shock.

Investigation of the Uptake and Transport of Two Novel Camptothecin Derivatives in Caco-2 Cell Monolayers.

Irinotecan and Topotecan are two Camptothecin derivatives (CPTs) whose resistance is associated with the high expression of breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp). To reverse this resistance, two novel CPTs, FL77-28 (7-(3-Fluoro-4-methylphenyl)-10,11-methylenedioxy-20(S)-CPT) and FL77-29 (7-(4-Fluoro-3-methylphenyl)-10,11-methylenedioxy-20(S)-CPT), were synthesized by our group. In this study, the anti-tumor activities of FL77-28, FL77-29, and their parent, FL118 (10,11-methylenedioxy-20(S)-CPT), were evaluated and the results showed that FL77-28 and FL77-29 had stronger anti-tumor activities than FL118. The transport and uptake of FL118, FL77-28, and FL77-29 were investigated in Caco-2 cells for the preliminary prediction of intestinal absorption. The apparent permeability coefficient from apical to basolateral (Papp AP-BL) values of FL77-28 and FL77-29 were (2.32 ± 0.04) × 10-6 cm/s and (2.48 ± 0.18) × 10-6 cm/s, respectively, suggesting that the compounds had moderate absorption. Since the transport property of FL77-28 was passive diffusion and the efflux ratio (ER) was less than 2, two chemical inhibitors were added to further confirm the involvement of efflux proteins. The results showed that FL77-28 was not a substrate of P-gp or BCRP, but FL77-29 was mediated by P-gp. In conclusion, FL77-28 might be a promising candidate to overcome drug resistance induced by multiple efflux proteins.

Depleting receptor tyrosine kinases EGFR and HER2 overcomes resistance to EGFR inhibitors in colorectal cancer.

BACKGROUND: Epidermal growth factor receptor (EGFR) inhibitors, including cetuximab and panitumumab, are valuable therapeutics for colorectal cancer (CRC), but resistance to these inhibitors is common. The reason for such resistance is not well understood, which hampers development of better therapeutic strategies. Although activating mutations in KRAS, BRAF and PIK3CA are considered major drivers of CRC resistance to EGFR inhibitors, therapeutic targeting of these drug resistance drivers has not produced substantial clinical benefit. METHODS: We exploited cell lines and mouse tumor models (cell line xenografts and patient derived xenografts) for experiments of genetic and pharmacologic depletion of EGFR and/or its family member HER2, including EGFR mutants, inhibition of EGFR ligand shedding, and biochemical analysis of signaling proteins, to delineate the mechanism of CRC resistance to EGFR inhibitors and to assess the therapeutic activity of PEPDG278D, which is a recombinant human protein that induces the degradation of both EGFR and HER2. RESULTS: The sensitivity of CRC cells to cetuximab and panitumumab correlates with the ability of these drugs to induce EGFR downregulation. PEPDG278D strongly inhibits oncogenic signaling and growth of CRC cells by causing profound depletion of EGFR and HER2, regardless of activating mutations of KRAS, BRAF and PIK3CA. siRNA knockdown of EGFR or HER2 also inhibits CRC cells resistant to EGFR inhibitors. Tumors harboring mutated KRAS, BRAF and/or PIK3CA also overexpress EGFR ligands, further suggesting that EGFR signaling remains important to the tumors. While excessive tumor-generated high-affinity EGFR ligands block target engagement by PEPDG278D, aderbasib, an inhibitor of ADAM10 and ADAM17, enables PEPDG278D to exert strong antitumor activity by inhibiting ligand shedding. Moreover, adding fluorouracil, which is commonly used in CRC treatment, to the combination of PEPDG278D and aderbasib further enhances tumor inhibition. CONCLUSIONS: Our study shows that CRC resistance to EGFR inhibitors results primarily from the inability of the inhibitors to downregulate their target and that a PEPDG278D-based combination treatment overcomes the resistance.

Molecular Glues: Capable Protein-Binding Small Molecules That Can Change Protein-Protein Interactions and Interactomes for the Potential Treatment of Human Cancer and Neurodegenerative Diseases.

Molecular glue (MG) compounds are a type of unique small molecule that can change the protein-protein interactions (PPIs) and interactomes by degrading, stabilizing, or activating the target protein after their binging. These small-molecule MGs are gradually being recognized for their potential application in treating human diseases, including cancer. Evidence suggests that small-molecule MG compounds could essentially target any proteins, which play critical roles in human disease etiology, where many of these protein targets were previously considered undruggable. Intriguingly, most MG compounds with high efficacy for cancer treatment can glue on and control multiple key protein targets. On the other hand, a single key protein target can also be glued by multiple MG compounds with distinct chemical structures. The high flexibility of MG-protein interaction profiles provides rich soil for the growth and development of small-molecule MG compounds that can be used as molecular tools to assist in unraveling disease mechanisms, and they can also facilitate drug development for the treatment of human disease, especially human cancer. In this review, we elucidate this concept by using various types of small-molecule MG compounds and their corresponding protein targets that have been documented in the literature.

FL118, acting as a 'molecular glue degrader', binds to dephosphorylates and degrades the oncoprotein DDX5 (p68) to control c-Myc, survivin and mutant Kras against colorectal and pancreatic cancer with high efficacy.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC), a difficult-to-treat cancer, is expected to become the second-largest cause of cancer-related deaths by 2030, while colorectal cancer (CRC) is the third most common cancer and the third leading cause of cancer deaths. Currently, there is no effective treatment for PDAC patients. The development of novel agents to effectively treat these cancers remains an unmet clinical need. FL118, a novel anticancer small molecule, exhibits high efficacy against cancers; however, the direct biochemical target of FL118 is unknown. METHODS: FL118 affinity purification, mass spectrometry, Nanosep centrifugal device and isothermal titration calorimetry were used for identifying and confirming FL118 binding to DDX5/p68 and its binding affinity. Immunoprecipitation (IP), western blots, real-time reverse transcription PCR, gene silencing, overexpression (OE) and knockout (KO) were used for analysing gene/protein function and expression. Chromatin IP was used for analysing protein-DNA interactions. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromid assay and human PDAC/CRC cell/tumour models were used for determining PDAC/CRC cell/tumour in vitro and in vivo growth. RESULTS: We discovered that FL118 strongly binds to dephosphorylates and degrades the DDX5 oncoprotein via the proteasome degradation pathway without decreasing DDX5 mRNA. Silencing and OE of DDX5 indicated that DDX5 is a master regulator for controlling the expression of multiple oncogenic proteins, including survivin, Mcl-1, XIAP, cIAP2, c-Myc and mutant Kras. Genetic manipulation of DDX5 in PDAC cells affects tumour growth. PDAC cells with DDX5 KO are resistant to FL118 treatment. Our human tumour animal model studies further indicated that FL118 exhibits high efficacy to eliminate human PDAC and CRC tumours that have a high expression of DDX5, while FL118 exhibits less effectiveness in PDAC and CRC tumours with low DDX5 expression. CONCLUSION: DDX5 is a bona fide FL118 direct target and can act as a biomarker for predicting PDAC and CRC tumour sensitivity to FL118. This would greatly impact FL118 precision medicine for patients with advanced PDAC or advanced CRC in the clinic. FL118 may act as a 'molecular glue degrader' to directly glue DDX5 and ubiquitination regulators together to degrade DDX5.

Cellular Uptake and Transport Characteristics of FL118 Derivatives in Caco-2 Cell Monolayers.

In the evaluation of the druggability of candidate compounds, it was vital to predict the oral bioavailability of compounds from apparent permeability (Papp) across Caco-2 cell-culture model of intestinal epithelium cultured on commercial transwell plate inserts. The study was to investigate the transport characteristics and permeability of FL118 (10, 11-Methylenedioxy-20(S)-camptothecin) derivatives 7-Q6 (7-(4-Ethylphenyl)-10, 11-methylenedioxy-20(S)-camptothecin) and 7-Q20 (7-(4-Trifluoromethylphenyl)-10, 11-methylenedioxy-20(S)-camptothecin). Transport characteristics and permeability of the tested compounds to the small intestine were assessed at different concentrations (0.5, 1 µM) via Caco-2 cell monolayers model in vitro. Uptake studies based on Caco-2 cells, including temperatures, concentrations, and the influence of efflux transporters, were combined to confirm the transport characteristics of the tested compounds. Furthermore, cytotoxicity results showed that the concentrations used in the experiments were non-toxic and harmless to cells. In addition, The Papp of 7-Q6 was (3.69 ± 1.07) × 10-6 cm/s with efflux ratio (ER) 0.98, while the Papp of 7-Q20 was (7.78 ± 0.89) × 10-6 cm/s with ER 1.05 for apical-to-basolateral (AP→BL) at 0.5 µM, suggesting that 7-Q20 might possess higher oral bioavailability in vivo. Furthermore, P-glycoprotein (P-gp) was proved to slightly affect the accumulations of 7-Q20, while the absorption of 7-Q6 was irrelevant with P-gp and breast cancer resistant protein (BCRP) based on the cellular uptake assays. Accordingly, 7-Q6 was completely absorbed by passive diffusion, and 7-Q20 was mainly dependent on passive diffusion with being effluxed by P-gp slightly. Meanwhile, both 7-Q6 and 7-Q20 were potential antitumor drugs that might exhibit high oral bioavailability in the body.

Multiple functions of the DEAD-box RNA helicase, DDX5 (p68), make DDX5 a superior oncogenic biomarker and target for targeted cancer therapy.

DDX5 (p68) is a well-known multifunctional DEAD-box RNA helicase and a transcription cofactor. Since its initial discovery more than three decades ago, DDX5 is gradually recognized as a potential biomarker and target for the treatment of various cancer types. Studies over the years significantly expanded our understanding of the functional diversity of DDX5 in various cancer types and extended our knowledge of its Mechanism of Action (MOA). This provides a rationale for the development of novel cancer therapeutics by using DDX5 as a biomarker and a therapeutic target. However, while most of the published studies have found DDX5 to be an oncogenic target and a cancer treatment-resistant biomarker, a few studies have reported that in certain scenarios, DDX5 may act as a tumor suppressor. After careful review of all the available relevant studies in the literature, we found that the multiple functions of DDX5 make it both a superior independent oncogenic biomarker and target for targeted cancer therapy. In this article, we will summarize the relevant studies on DDX5 in literature with a careful analysis and discussion of any inconsistencies encountered, and then provide our conclusions with respect to understanding the MOA of FL118, a novel small molecule. We hope that such a review will stimulate further discussion on this topic and assist in developing better strategies to treat cancer by using DDX5 as both an oncogenic biomarker and therapeutic target.

Evaluation of acupuncture treatments of postpartum female pelvic floor dysfunction by four-dimensional transperineal pelvic floor ultrasound.

INTRODUCTION: In the present investigation, a systematic evaluation of the clinical treatment performance of diagnosed with pelvic floor dysfunction is explored. By comparing the 4Dtransperineal pelvic floor ultrasound images with the acupuncture treatment performance of the patients, an evaluation system with various parameters is established to provide critical information to guide the clinical treatment fpostpartum female pelvic floor dysfunction (FPFD). METHODS: Eighty patients diagnosed with FPFD are divided into 2 groups. After the designated treatment to the patients, they are carefully examined using transperineal pelvic floor ultrasound. The shape and activity of bladder neck, cervix and rectum anal canal under resting, anal sphincter and Valsalva movements are observed and recorded. The morphology and continuous shape of levator ani muscle in different states after 4D image reconstruction are obtained. RESULTS: After the acupuncture treatment, the bladder neck descent is decreased by 3.8 cm and the anal levator muscle area is decreased by 3.4 cm2 comparing with the control group. The anal levator muscle hole diameter is decreased by 0.3 cm, while the anterior and posterior diameter is reduced by 0.5 cm. Reduced possibility of cystocele and uterine prolapse is demonstrated by X2 test. These changes upon acupuncture therapy are in line with the improved conditions of the patients, indicating these parameters can help evaluate the therapy performance. CONCLUSION: 4D pelvic floor ultrasound imaging provides objective and quantified information for the clinical diagnosis and treatment of FPFD and the assessment of therapy efficacy, making it a promising novel method in practical applications.