Monitoring of T790M in plasma ctDNA of advanced EGFR-mutant NSCLC patients on first- or second-generation tyrosine kinase inhibitors.

BACKGROUND: The T790M mutation is the major resistance mechanism to first- and second-generation TKIs in EGFR-mutant NSCLC. This study aimed to investigate the utility of droplet digital PCR (ddPCR) for detection of T790M in plasma circulating tumor DNA (ctDNA), and explore its impact on prognosis. METHODS: This prospective study enrolled 80 advanced lung adenocarcinoma patients treated with gefitinib, erlotinib, or afatinib for TKI-sensitizing mutations between 2015 and 2019. Plasma samples were collected before TKI therapy and at tri-monthly intervals thereafter. Genotyping of ctDNA for T790M was performed using a ddPCR EGFR Mutation Assay. Patients were followed up until the date of death or to the end of 2021. RESULTS: Seventy-five of 80 patients experienced progressive disease. Fifty-three (71%) of 75 patients underwent rebiopsy, and T790M mutation was identified in 53% (28/53) of samples. Meanwhile, plasma ddPCR detected T790M mutation in 23 (43%) of 53 patients. The concordance rate of T790M between ddPCR and rebiopsy was 76%, and ddPCR identified 4 additional T790M-positive patients. Ten (45%) of 22 patients who did not receive rebiopsy tested positive for T790M by ddPCR. Serial ddPCR analysis showed the time interval from detection of plasma T790M to objective progression was 1.1 (0-4.1) months. Compared to 28 patients with rebiopsy showing T790M, the overall survival of 14 patients with T790M detected solely by ddPCR was shorter(41.3 [95% CI, 36.6-46.0] vs. 26.6 months [95% CI, 9.9-43.3], respectively). CONCLUSION: Plasma ddPCR-based genotyping is a useful technology for detection and monitoring of the key actionable genomic alteration, namely, T790M, in patients treated with gefitinib, erlotinib, or afatinib for activating mutations, to achieve better patient care and outcome.

Co-location with marketing value activities as manufacturing upgrading in a COVID-19 outbreak era.

Co-location has been a relevant topic in the international business literature, yet the extant literature focuses on the co-location of research and development (R&D) and production activities and overlooks marketing value activities. Marketing innovation is an agile and effective way to respond to crises such as the COVID-19 pandemic, and many manufacturers in global value chains aim to upgrade functionally following the trajectory of the OEM-ODM-OBM. Thus, this study proposes the co-location of marketing activities as a flexible and organizational learning strategy for manufacturing upgrades, and explores the antecedents of marketing co-location in foreign direct investment (FDI) decisions. The proposed research framework was examined using survey data from 343 Taiwanese manufacturing firms in China, which were drawn from a database compiled by Taiwan's Ministry of Economic Affairs in 2020. The results show that the breadth of international experience, linkage to R&D, marketing as a primary knowledge source in the host country, upgrading for local demands, and new product development for global supply are all positively associated with the co-location of marketing and production functions. Additionally, it was found that there was a negative association between FDIs that had been impacted by COVID-19 and marketing co-location. The findings provide valuable theoretical, practical, and strategic insights into how firms should manage their global value chains with respect to marketing co-location in case of another crisis.

The M1/M2 spectrum and plasticity of malignant pleural effusion-macrophage in advanced lung cancer.

BACKGROUND: Malignant pleural effusion (MPE)-macrophage (Mφ) of lung cancer patients within unique M1/M2 spectrum showed plasticity in M1-M2 transition. The M1/M2 features of MPE-Mφ and their significance to patient outcomes need to be clarified; furthermore, whether M1-repolarization could benefit treatment remains unclear. METHODS: Total 147 stage-IV lung adenocarcinoma patients undergoing MPE drainage were enrolled for profiling and validation of their M1/M2 spectrum. In addition, the MPE-Mφ signature on overall patient survival was analyzed. The impact of the M1-polarization strategy of patient-derived MPE-Mφ on anti-cancer activity was examined. RESULTS: We found that MPE-Mφ expressed both traditional M1 (HLA-DRA) and M2 (CD163) markers and showed a wide range of M1/M2 spectrum. Most of the MPE-Mφ displayed diverse PD-L1 expression patterns, while the low PD-L1 expression group was correlated with higher levels of IL-10. Among these markers, we identified a novel two-gene MPE-Mφ signature, IL-1ß and TGF-ß1, representing the M1/M2 tendency, which showed a strong predictive power in patient outcomes in our MPE-Mφ patient cohort (N = 60, p = 0.013) and The Cancer Genome Atlas Lung Adenocarcinoma dataset (N = 478, p < 0.0001). Significantly, ß-glucan worked synergistically with IFN-γ to reverse the risk signature by repolarizing the MPE-Mφ toward the M1 pattern, enhancing anti-cancer activity. CONCLUSIONS: We identified MPE-Mφ on the M1/M2 spectrum and plasticity and described a two-gene M1/M2 signature that could predict the outcome of late-stage lung cancer patients. In addition, we found that "re-education" of these MPE-Mφ toward anti-cancer M1 macrophages using clinically applicable strategies may overcome tumor immune escape and benefit anti-cancer therapies.

Comprehensive profiling of amino acid response uncovers unique methionine-deprived response dependent on intact creatine biosynthesis.

Besides being building blocks for protein synthesis, amino acids serve a wide variety of cellular functions, including acting as metabolic intermediates for ATP generation and for redox homeostasis. Upon amino acid deprivation, free uncharged tRNAs trigger GCN2-ATF4 to mediate the well-characterized transcriptional amino acid response (AAR). However, it is not clear whether the deprivation of different individual amino acids triggers identical or distinct AARs. Here, we characterized the global transcriptional response upon deprivation of one amino acid at a time. With the exception of glycine, which was not required for the proliferation of MCF7 cells, we found that the deprivation of most amino acids triggered a shared transcriptional response that included the activation of ATF4, p53 and TXNIP. However, there was also significant heterogeneity among different individual AARs. The most dramatic transcriptional response was triggered by methionine deprivation, which activated an extensive and unique response in different cell types. We uncovered that the specific methionine-deprived transcriptional response required creatine biosynthesis. This dependency on creatine biosynthesis was caused by the consumption of S-Adenosyl-L-methionine (SAM) during creatine biosynthesis that helps to deplete SAM under methionine deprivation and reduces histone methylations. As such, the simultaneous deprivation of methionine and sources of creatine biosynthesis (either arginine or glycine) abolished the reduction of histone methylation and the methionine-specific transcriptional response. Arginine-derived ornithine was also required for the complete induction of the methionine-deprived specific gene response. Collectively, our data identify a previously unknown set of heterogeneous amino acid responses and reveal a distinct methionine-deprived transcriptional response that results from the crosstalk of arginine, glycine and methionine metabolism via arginine/glycine-dependent creatine biosynthesis.

Development of a zinc chloride-based chemo-mechanical system for potential minimally invasive dental caries removal system.

Background/purpose: The chemo-mechanical caries-removal technique is known to offer advantages of selective dentin caries treatment while leaving healthy dental tissues intact. However, current sodium hypochlorite based reagents usually excessively damage dentin collagen. Therefore, the purpose of this study was to develop a novel chemo-mechanical caries-removal system to preserve the collagen network for subsequent prosthetic restorations. Materials and methods: The calfskin-derived collagen was chosen as a model system to investigate the dissolution behavior of collagen under different operating conditions of chemical-ultrasonic treatment systems. The molecular weight, triple-helix structure, the morphology, and functional group of collagen after treatment were investigated. Results: Various concentrations of sodium hypochlorite or zinc chloride together with ultrasonic machinery were chosen to investigate. The outcomes of circular dichroism (CD) spectra demonstrated stability of the triple-helix structure after treatment of a zinc chloride solution. In addition, two apparent bands at molecular weights (MWs) of 130 and 121 kDa evidenced the stability of collagen network. The positive 222 nm and 195 nm negative CD absorption band indicated the existence of a triple-helix structure for type I collagen. The preservation of the morphology and functional group of the collagen network on the etched dentin surface were investigated by in vitro dentin decalcification model. Conclusion: Unlike NaOCl, the 5 wt% zinc chloride solution combined with ultra-sonication showed dissolution rather than denature as well as degradation of the dentin collagen network. Additional in vivo evaluations are needed to verify its usefulness in clinical applications.

The Optimal Primary Treatment for Pediatric Perianal Abscess and Anal Fistula: A Systemic Review and Meta-Analysis.

BACKGROUND: Perianal abscesses and anal fistulas are common. The principle of intention-to-treat has not been considered in previous systemic reviews. Thus, the comparison between primary and post-recurrence management was confused, and the recommendation of primary treatment is obscure. The current study aims to identify the optimal initial treatment for pediatric patients. METHODS: Using PRISMA guidelines, studies were identified from MEDLINE, EMBASE, PubMed, Cochrane Library, and Google Scholar without any language or study design restriction. The inclusion criteria include original articles or articles with original data, studies of management for a perianal abscess with or without anal fistula, and patient age of <18 years. Patients with local malignancy, Crohn's disease, or other underlying predisposing conditions were excluded. Studies without analyzing recurrence, case series of <5, and irrelevant articles were excluded in the screening stage. Of the 124 screened articles, 14 articles had no full texts or detailed information. Articles written in a language other than English or Mandarin were translated by Google Translation first and confirmed with native speakers. After the eligibility process, studies that compared identified primary managements were then included in the qualitative synthesis. RESULTS: Thirty-one studies involving 2507 pediatric patients met the inclusion criteria. The study design consisted of two prospective case series of 47 patients and retrospective cohort studies. No randomized control trials were identified. Meta-analyses for recurrence after initial management were performed with a random-effects model. Conservative treatment and drainage revealed no difference (Odds ratio [OR], 1.222; 95% Confidential interval [CI]: 0.615-2.427, p = 0.567). Conservative management had a higher risk of recurrence than surgery without statistical significance (OR 0.278, 95% CI: 0.109-0.707, p = 0.007). Compared with incision/drainage, surgery can prevent recurrence remarkably (OR 4.360, 95% CI: 1.761-10.792, p = 0.001). Subgroup analysis of different approaches within conservative treatment and operation was not performed for lacking information. CONCLUSION: Strong recommendations cannot be made due to the lack of prospective or randomized controlled studies. However, the current study based on real primary management supports initial surgical intervention for pediatric patients with perianal abscesses and anal fistula to prevent recurrence. LEVEL OF EVIDENCE: Type of study: Systemic review; Evidence level: Level II.

Development of triamcinolone acetonide-hyaluronic acid conjugates with selective targeting and less osteoporosis effect for rheumatoid arthritis treatments.

Rheumatoid arthritis (RA) is a common systemic autoimmune disease in developed countries. In clinical treatment, steroids have been used as bridging and adjunctive therapy after disease-modifying anti-rheumatic drug administration. However, the severe side effects caused by the nonspecific targeting of organs followed by long-term administration have limited their usage in RA. In this study, poorly water-soluble triamcinolone acetonide (TA), a highly potent corticosteroid for intra-articular injection, is conjugated on hyaluronic acid (HA) for intravenous purposes with increased specific drug accumulation in inflamed parts for RA. Our results demonstrate that the designed HA/TA coupling reaction reveals >98 % conjugation efficiency in the dimethyl sulfoxide/water system, and the resulting HA-TA conjugates show lower osteoblastic apoptosis compared with that in free TA-treated osteoblast-like NIH3T3 cells. Furthermore, in a collagen-antibody-induced arthritis animal study, HA-TA conjugates enhanced the initiative targeting ability to inflame tissue and reduce the histopathological arthritic changes (score = 0). Additionally, the level of bone formation marker P1NP in HA-TA-treated ovariectomized mice (303.6 ± 40.6 pg/mL) is significantly higher than that in the free TA-treated group (143.1 ± 3.9 pg/mL), indicating the potential for osteoporotic reduction using an efficient HA conjugation strategy for the long-term administration of steroids against RA.

Soluble triggering receptor expressed on myeloid cells-1 as an infection marker for patients with neutropenic fever.

OBJECTIVE: To assess the value of soluble triggering receptor expressed on myeloid cells-1 as a biomarker of infection in patients with neutropenic fever comparing with procalcitonin and C-reactive protein. DESIGN: Prospective, comparative, single-center study. SETTING: Hematology ward at a university hospital. SUBJECTS: Seventy-five patients with neutropenic fever after chemotherapy for their hematologic malignancies. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: A total of 137 episodes of neutropenic fever in 75 patients were classified into 75 episodes of documented infections and 62 low likelihood of infection. The level of soluble triggering receptor expressed on myeloid cells-1 was significantly elevated in the group of documented infection. The area under the receiver operating characteristic curve for the diagnosis of infection was 0.719 (95% confidence interval, 0.632-0.806; p < .0001) for soluble triggering receptor expressed on myeloid cells-1, which was larger than the values of 0.501 for procalcitonin (0.465-0.657; p = .218) and 0.491 for C-reactive protein (0.394-0.589, p = .858). The fitted marginal logistic regression model of all episodes contained two statistically significant predictors of infection: soluble triggering receptor expressed on myeloid cells-1 (per 1-pg/mL increase; odds ratio [OR], 1.0002; 95% CI, 1.0001-1.0003; p < .0001) and procalcitonin (per 1-ng/mL increase; OR, 1.0094; 95% CI, 1.0005-1.0184; p = .0002). In a diagnostic panel with soluble triggering receptor expressed on myeloid cells-1 and procalcitonin, the sensitivity and specificity were 88% and 48%, respectively. CONCLUSIONS: Soluble triggering receptor expressed on myeloid cells-1 is better than procalcitonin in the prediction of infection at the onset of neutropenic fever. By applying soluble triggering receptor expressed on myeloid cells-1 and procalcitonin together, low or high risk for infection can be defined at the onset of neutropenic fever.

Effects of Eye Drops Containing Hyaluronic Acid-Nimesulide Conjugates in a Benzalkonium Chloride-Induced Experimental Dry Eye Rabbit Model.

Dry eye syndrome (DES) is a common ocular disease worldwide. Currently, anti-inflammatory agents and immunosuppressive drugs, such as cyclosporine A, have been widely used to treat this chronic condition. However, the multifactorial etiology of DES, poor tolerance, low bioavailability, and prolonged treatment to response time have limited their usage. In this study, nimesulide, a cyclooxygenase (COX)-2 selective inhibitor, was conjugated with hyaluronic acid (HA), and the HA-nimesulide conjugates were expected to increase the solubility and biocompatibility for alleviating the DES in the benzalkonium chloride (BAC)-induced goblet cell-loss dry eye model. The therapeutic efficacy of HA-nimesulide was assessed using fluorescein staining, goblet cell density by conjunctival impression cytology, and histology and immunohistochemistry of corneal tissues. Compared to commercial artificial tears and Restasis®, the HA-nimesulide conjugates could promote goblet cell recovery and enhance the regeneration of the corneal epithelium. Importantly, immunofluorescent staining studies demonstrated that the HA-nimesulide conjugates could decrease the number of infiltrating CD11b-positive cells after two weeks of topical application. In the anti-inflammatory test, the HA-nimesulide conjugates could inhibit the production of pro-inflammatory cytokines and prostaglandin E2 (PGE2) in the lipopolysaccharide (LPS)-stimulated Raw 264.7 cell model. In conclusion, we demonstrated that HA-nimesulide conjugates had anti-inflammatory activity, and promoted goblet cell recovery and corneal epithelium regeneration when used as topical eye drops; accordingly, the HA-nimesulide conjugates could potentially be effective for the treatment of DES.

Hyaluronic Acid-Glycine-Cholesterol Conjugate-Based Nanoemulsion as a Potent Vaccine Adjuvant for T Cell-Mediated Immunity.

Clinical cases of allergic reaction that are due to excipients containing polyethylene glycol (PEG), a hydrophilic molecule commonly used in drug/vaccine formulations, has attracted much attention in recent years. In order to develop PEG-free adjuvants, we investigated the feasibility of natural ingredients in the human body such as hyaluronic acid in the form of hyaluronic acid-glycine cholesterol (HACH) conjugate as an excipient for vaccine formulation. Interestingly, HACH grafted with ~13 wt.% cholesterol has good water dispersity and can serve as an emulsifier to stabilize the squalene/water interfaces, yielding a milky white and isotropic emulsion (SQ@HACH) after being passed through a high-shear microfluidizer. Our results show that SQ@HACH particles possessed a unimodal average hydrodynamic diameter of approximately 190 nm measured by dynamic light scattering and exhibited good stability upon storage at 4 °C and 37 °C for over 20 weeks. The results of immunogenicity using a mouse model with ovalbumin (OVA) as the antigen revealed that SQ@HACH significantly enhanced antigen-specific immune responses, including the polarization of IgG antibodies, the cytokine secretions of T cells, and enhancement of cytotoxic T lymphocyte (CTL) activation. Moreover, SQ@HACH revealed lower local inflammation and rapidly absorbing properties compared with AlPO4 after intramuscular injection in vivo, indicating the potential functions of the HA-derived conjugate as an excipient in vaccine formulations for enhancement of T cell-mediated immunity.

Molecular Characterization and Pathogenicity of the Novel Recombinant Muscovy Duck Parvovirus Isolated from Geese.

Goose parvovirus (GPV) and Muscovy duck parvovirus (MDPV) are the main agents associated with waterfowl parvovirus infections that caused great economic losses in the waterfowl industry. In 2020, a recombinant waterfowl parvovirus, 20-0910G, was isolated in a goose flock in Taiwan that experienced high morbidity and mortality. The whole genome of 20-0910G was sequenced to investigate the genomic characteristics of this isolate. Recombination analysis revealed that, like Chinese rMDPVs, 20-0910G had a classical MDPV genomic backbone and underwent two recombination events with classical GPVs at the P9 promoter and partial VP3 gene regions. Phylogenetic analysis of the genomic sequence found that this goose-origin parvovirus was highly similar to the circulating recombinant MDPVs (rMDPVs) isolated from duck flocks in China. The results of experimental challenge tests showed that 20-0910G caused 100% mortality in goose embryos and in 1-day-old goslings by 11 and 12 days post-inoculation, respectively. Taken together, the results indicated that this goose-origin rMDPV was closely related to the duck-origin rMDPVs and was highly pathogenic to young geese.

Vorinostat combined with brigatinib overcomes acquired resistance in EGFR-C797S-mutated lung cancer.

The development of a new generation of tyrosine kinase inhibitors (TKIs) has improved the treatment response in lung adenocarcinomas. However, acquired resistance often occurs due to new epidermal growth factor receptor (EGFR) mutations. In particular, the C797S mutation confers drug resistance to T790M-targeting EGFR TKIs. To address C797S resistance, a promising therapeutic avenue is combination therapy that targets both total EGFR and acquired mutations to increase drug efficacy. We showed that combining vorinostat, a histone deacetylase inhibitor (HDACi), with brigatinib, a TKI, enhanced antitumor effects in primary culture and cell lines of lung adenocarcinomas harboring EGFR L858R/T790M/C797S mutations (EGFR-3M). While EGFR phosphorylation was decreased by brigatinib, vorinostat reduced total EGFR-3M (L858R/T790M/C797S) proteins through STUB1-mediated ubiquitination and degradation. STUB1 preferably ubiquitinated other EGFR mutants and facilitated protein turnover compared to EGFR-WT. The association between EGFR and STUB1 required the functional chaperone-binding domain of STUB1 and was further enhanced by vorinostat. Finally, STUB1 levels modulated EGFR downstream functions. Low STUB1 expression was associated with significantly poorer overall survival than high STUB1 expression in patients harboring mutant EGFR. Vorinostat combined with brigatinib significantly improved EGFR-TKI sensitivity to EGFR C797S by inducing EGFR-dependent cell death and may be a promising therapy in treating C797S-resistant lung adenocarcinomas.

Serum soluble triggering receptor expressed on myeloid cells-1 in acute respiratory distress syndrome: a prospective observational cohort study.

BACKGROUND/PURPOSE: Serum soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), a detector of acute inflammatory response to microbial products and a good marker for diagnosing sepsis and pneumonia, has not yet been described as a predictor for infection or a prognostic factor in patients with acute respiratory distress syndrome (ARDS). METHODS: This prospective observational cohort study enrolled 63 ventilated adult patients with ARDS; 50 as septic and 13 as non-septic, and followed them for 28 days in intensive care units at a university hospital in Taiwan. Serial serum sTREM-1 levels and cytokines, such as interleukin (IL)-1, IL-8, and tumor necrosis factor-α, on days 1, 3, 5, 7 and 14 were measured by an enzyme-linked immunosorbent assay. The association between biomarkers and clinical infectious diagnosis/outcome in ARDS was explored. RESULTS: Serum sTREM-1 and cytokine levels could not differentiate septic from non-septic ARDS. Serum log sTREM-1 and inflammatory cytokine levels were correlated positively (r = 0.325 for IL-1ß; r = 0.247 for IL-8; r = 0.480 for tumor necrosis factor-α). As prognostic factors, higher serum sTREM-1 level on day 1 and increasing levels over time, especially in the first 5 days, were independent predictors of mortality on day 28, using a multivariate Cox regression model. Serum sTREM-1 levels remained stable or even increased in the non-surviving patients, but decreased in the survivors. CONCLUSION: Serum sTREM-1 level might not be a reliable marker for infection in ARDS patients. However, as an inflammatory marker, initial serum sTREM-1 level and its trend over time, especially in the first 5 days, could be predictive of short-term mortality. A progressive decline in serum sTREM-1 levels during follow-up indicates a favorable outcome, whereas persistently elevated sTREM-1 indicates a poor prognosis and should lead to a re-evaluation of therapy.

EGFR-Mutant SCLC Exhibits Heterogeneous Phenotypes and Resistance to Common Antineoplastic Drugs.

INTRODUCTION: Approximately 5% of patients with EGFR-activating mutations acquire EGFR tyrosine kinase inhibitor (TKI) resistance through SCLC transformation. However, the reason for the poor outcome and the molecular basis of EGFR-mutant SCLC that has transformed from adenocarcinoma remain unclear. METHODS: In this study, we established two EGFR-mutant SCLC cell lines from lung adenocarcinoma patients after failed EGFR-TKI treatment to investigate their molecular basis and potential therapeutic strategies in the hope of improving patient outcome. RESULTS: These two EGFR-mutant SCLC cell lines displayed two different phenotypes: suspensive and adherent. Both phenotypes shared the same genomic alterations analyzed by array-based comparative genomic hybridization assay. Increased expression of EGFR and mesenchymal markers and decreased expression of neuroendocrine markers were observed in adherent cells. Principal component analysis and hierarchical clustering analysis of RNA microarray revealed that these two cell lines displayed a unique gene expression pattern that was distinctly different from that in NSCLC and classical SCLC cells. Combined treatment using an EGFR-TKI and an AKT inhibitor attenuated cell viabilities in our two cell lines. Moreover, the use of a histone deacetylase inhibitor significantly inhibited the cell viabilities of both cell lines in vitro and in vivo. CONCLUSION: Our findings suggest that EGFR-mutant SCLC may be a distinct subclass of SCLC that exhibits epithelial-mesenchymal transition phenotypes, and adding an AKT or histone deacetylase inhibitor to pre-existing therapies may be one of the therapeutic choices for transformed EGFR-mutant SCLC.

Acquired BRAF V600E Mutation as Resistant Mechanism after Treatment with Osimertinib.

INTRODUCTION: AZD9291 (osimertinib) is designed for acquired T790M mutation after first- and second-generation EGFR) tyrosine kinase inhibitors have been used. Some of the resistance mechanisms that present after osimertinib treatment, including a newly acquired EGFR C797S mutation, have been identified. It is unclear, however, whether the bypass pathway is also a mechanism of resistance in patients after osimertinib treatment. METHODS: Cells from malignant pleural effusion were collected and cultured at the time of progression in a patient being treated with osimertinib. Tumor genotyping was done by matrix-assisted laser desorption ionization-time of flight mass spectrometry. EGFR, AKT, MEK, and ERK phosphorylation were determined. An anchorage-dependent colony formation assay was used for drug sensitivity. RESULTS: An acquired mutation, BRAF V600E, was found in the patient at the time of progression while being treated with osimertinib. Cells grown from malignant pleural effusion were sensitive to BRAF V600E inhibitor and were more vulnerable to a combination treatment with osimertinib. CONCLUSIONS: A potential mechanism of acquired resistance to osimertinib in patients with T790M is through the BRAF pathway. Simultaneous blockade of the BRAF and EGFR had a significant inhibitory effect.

Hyaluronic acid-nimesulide conjugates as anticancer drugs against CD44-overexpressing HT-29 colorectal cancer in vitro and in vivo.

Carrier-mediated drug delivery systems are promising therapeutics for targeted delivery and improved efficacy and safety of potent cytotoxic drugs. Nimesulide is a multifactorial cyclooxygenase 2 nonsteroidal anti-inflammatory drug with analgesic, antipyretic and potent anticancer properties; however, the low solubility of nimesulide limits its applications. Drugs conjugated with hyaluronic acid (HA) are innovative carrier-mediated drug delivery systems characterized by CD44-mediated endocytosis of HA and intracellular drug release. In this study, hydrophobic nimesulide was conjugated to HA of two different molecular weights (360 kDa as HA with high molecular weight [HAH] and 43kDa as HA with low molecular weight [HAL]) to improve its tumor-targeting ability and hydrophilicity. Our results showed that hydrogenated nimesulide (N-[4-amino-2-phenoxyphenyl]methanesulfonamide) was successfully conjugated with both HA types by carbodiimide coupling and the degree of substitution of nimesulide was 1%, which was characterized by 1H nuclear magnetic resonance 400 MHz and total correlation spectroscopy. Both Alexa Fluor® 647 labeled HAH and HAL could selectively accumulate in CD44-overexpressing HT-29 colorectal tumor area in vivo, as observed by in vivo imaging system. In the in vitro cytotoxic test, HA-nimesulide conjugate displayed >46% cell killing ability at a nimesulide concentration of 400 µM in HT-29 cells, whereas exiguous cytotoxic effects were observed on HCT-15 cells, indicating that HA-nimesulide causes cell death in CD44-overexpressing HT-29 cells. Regarding in vivo antitumor study, both HAL-nimesulide and HAH-nimesulide caused rapid tumor shrinkage within 3 days and successfully inhibited tumor growth, which reached 82.3% and 76.4% at day 24 through apoptotic mechanism in HT-29 xenografted mice, without noticeable morphologic differences in the liver or kidney, respectively. These results indicated that HA-nimesulide with improved selectivity through HA/CD44 receptor interactions has the potential to enhance the therapeutic efficacy and safety of nimesulide for cancer treatment.

Hedgehog pathway maintains cell survival under stress conditions, and drives drug resistance in lung adenocarcinoma.

Hedgehog (HH) pathway plays an important role in embryonic development, but is largely inactive in adult except for tissue repair. Aberrant activation of HH pathway has been found in a variety of cancer types. In non-small cell lung cancer, however, the role and importance of HH pathway remain controversial. In the current study, we found that HH pathway was maintained in low activity in lung adenocarcinoma (LAC) cells under normal culture condition, but was highly induced in response to stress conditions. Activation of HH pathway promoted cell survival, growth, and invasion partially through HGF and MET signaling. Hedgehog-Interacting Protein (HHIP), a cell-surface negative regulator of HH pathway, was epigenetically silenced in LAC. Overexpression of HHIP blocked the activation of HH and HGF/MET pathways, and made cells significantly more susceptible to stress conditions. In LAC cells with acquired resistance to Epidermal Growth Factor Receptor Tyrosin Kinase Inhibitor (EGFR-TKI), we found that a part of tumor cells were much more sensitive to HH or HGF/MET inhibitors, suggesting an oncogenic addiction shift from EGFR to HH and HGF/MET pathways. In conclusion, this study showed that HH pathway is a survival signaling that drives LAC cell growth under stress conditions, and HHIP is a key regulator to block the induction of HH pathway. Targeting the HH pathway through inhibitors or HHIP thus holds promise to address EGFR-TKI resistance in LAC in clinic.

Cystine Deprivation Triggers Programmed Necrosis in VHL-Deficient Renal Cell Carcinomas.

Oncogenic transformation may reprogram tumor metabolism and render cancer cells addicted to extracellular nutrients. Deprivation of these nutrients may therefore represent a therapeutic opportunity, but predicting which nutrients cancer cells become addicted remains difficult. Here, we performed a nutrigenetic screen to determine the phenotypes of isogenic pairs of clear cell renal cancer cells (ccRCC), with or without VHL, upon the deprivation of individual amino acids. We found that cystine deprivation triggered rapid programmed necrosis in VHL-deficient cell lines and primary ccRCC tumor cells, but not in VHL-restored counterparts. Blocking cystine uptake significantly delayed xenograft growth of ccRCC. Importantly, cystine deprivation triggered similar metabolic changes regardless of VHL status, suggesting that metabolic responses alone are not sufficient to explain the observed distinct fates of VHL-deficient and restored cells. Instead, we found that increased levels of TNFα associated with VHL loss forced VHL-deficient cells to rely on intact RIPK1 to inhibit apoptosis. However, the preexisting elevation in TNFα expression rendered VHL-deficient cells susceptible to necrosis triggered by cystine deprivation. We further determined that reciprocal amplification of the Src-p38 (MAPK14)-Noxa (PMAIP1) signaling and TNFα-RIP1/3 (RIPK1/RIPK3)-MLKL necrosis pathways potentiated cystine-deprived necrosis. Together, our findings reveal that cystine deprivation in VHL-deficient RCCs presents an attractive therapeutic opportunity that may bypass the apoptosis-evading mechanisms characteristic of drug-resistant tumor cells. Cancer Res; 76(7); 1892-903. ©2016 AACR.