5-Fluorouracil resistance due to sphingosine kinase 2 overexpression in colorectal cancer is associated with myeloid-derived suppressor cell-mediated immunosuppressive effects.

PURPOSE: Colorectal cancer (CRC) is one of the top five cancer-related causes of mortality globally. Acquired resistance has hindered the effectiveness of 5-fluorouracil (5-FU), the main chemotherapeutic drug used to treat CRC. Sphingosine kinase 2 (SphK2) may be a cancer treatment target and involved in 5-FU resistance. METHODS: Cell growth was examined using MTT and clone formation assays for SphK2 expression. To identify immune cells in mice, flow cytometry was performed. West blotting demonstrated alterations in cell division and inflammation-related proteins. SphK2 levels and inflammation-related variables were studied using Elisa. RESULTS: Due to SphK2 overexpression, immunosuppression, and 5-FU resistance are caused by the development of myeloid-derived suppressor cells (MDSCs) subsequent to IL-6/STAT3 activation and alterations in the arginase (ARG-1) protein. After therapy, the combination of SphK2 inhibitors and 5-FU can effectively suppress MDSCs while increasing CD4+ and CD8+ T cell infiltration into the tumor microenvironment, lowering tumor burden, and exhibiting a therapeutic impact on CRC. CONCLUSIONS: Our findings suggest that 5-FU treatment combined with simultaneous Spkh2 inhibition by ABC294640 has anti-tumor synergistic effects by influencing multiple effects on tumor cells, T cells, and MDSCs, potentially improving the poor prognosis of colorectal cancer patients.

Dimeric Her2-specific affibody mediated cisplatin-loaded nanoparticles for tumor enhanced chemo-radiotherapy.

BACKGROUND: Solid tumor hypoxic conditions prevent the generation of reactive oxygen species (ROS) and the formation of DNA double-strand breaks (DSBs) induced by ionizing radiation, which ultimately contributes to radiotherapy (RT) resistance. Recently, there have been significant technical advances in nanomedicine to reduce hypoxia by facilitating in situ O2 production, which in turn serves as a "radiosensitizer" to increase the sensitivity of tumor cells to ionizing radiation. However, off-target damage to the tumor-surrounding healthy tissue by high-energy radiation is often unavoidable, and tumor cells that are further away from the focal point of ionizing radiation may avoid damage. Therefore, there is an urgent need to develop an intelligent targeted nanoplatform to enable precise enhanced RT-induced DNA damage and combined therapy. RESULTS: Human epidermal growth factor receptor 2 (Her2)-specific dimeric affibody (ZHer2) mediated cisplatin-loaded mesoporous polydopamine/MnO2/polydopamine nanoparticles (Pt@mPDA/MnO2/PDA-ZHer2 NPs) for MRI and enhanced chemo-radiotherapy of Her2-positive ovarian tumors is reported. These NPs are biodegradable under a simulated tumor microenvironment, resulting in accelerated cisplatin release, as well as localized production of O2. ZHer2, produced using the E. coli expression system, endowed NPs with Her2-dependent binding ability in Her2-positive SKOV-3 cells. An in vivo MRI revealed obvious T1 contrast enhancement at the tumor site. Moreover, these NPs achieved efficient tumor homing and penetration via the efficient internalization and penetrability of ZHer2. These NPs exhibited excellent inhibition of tumor growth with X-ray irradiation. An immunofluorescence assay showed that these NPs significantly reduced the expression of HIF-1α and improved ROS levels, resulting in radiosensitization. CONCLUSIONS: The nanocarriers described in the present study integrated Her2 targeting, diagnosis and RT sensitization into a single platform, thus providing a novel approach for translational tumor theranostics.

High mobility group box 1/toll-like receptor 4/myeloid differentiation factor 88 signaling promotes progression of gastric cancer.

High mobility group box 1 and toll-like receptor 4/myeloid differentiation factor 88 signaling pathway have been indicated to have oncogenic effects in many cancers. However, the role of high mobility group box 1/toll-like receptor 4/myeloid differentiation factor 88 signaling pathway in the development of gastric cancer remains unclear. In this study, we demonstrated that high mobility group box 1, toll-like receptor 4, and myeloid differentiation factor 88 were overexpressed in gastric cancer tumors compared with the adjacent non-tumor tissues. The overexpression of high mobility group box 1, toll-like receptor 4, and myeloid differentiation factor 88 were correlated with tumor-node-metastasis stage (p = 0.0068, p = 0.0063, p = 0.0173) and lymph node metastasis (p = 0.0272, p = 0.0382, and p = 0.0495). Furthermore, we observed that knockdown of high mobility group box 1 by high mobility group box 1-small interfering RNA suppressed the expression of toll-like receptor 4 and myeloid differentiation factor 88. Blockage of high mobility group box 1/toll-like receptor 4/myeloid differentiation factor 88 signaling by high mobility group box 1-small interfering RNA resulted in elevation of apoptotic ratio and inhibition of cell growth, migration, and invasion by upregulating Bax expression and downregulating Bcl-2, matrix metalloproteinase-2, nuclear factor kappa B/p65 expression, and the nuclear translocation of nuclear factor kappa B/p65 in gastric cancer cells. Our findings suggest that high mobility group box 1/toll-like receptor 4/myeloid differentiation factor 88 signaling pathway may contribute to the development and progression of gastric cancer via the nuclear factor kappa B pathway and it also represents a novel potential therapeutic target for gastric cancer.

Optimal staging system for predicting the prognosis of patients with hepatocellular carcinoma in China: a retrospective study.

BACKGROUND: Several staging systems have been developed to evaluate patients with hepatocellular carcinoma (HCC), including the China Staging System (CS), the American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) staging system, and seventh edition; the Barcelona Clinic Liver Cancer (BCLC) staging system, and Cancer of the Liver Italian Program (CLIP) staging system. The optimal staging system for to evaluate patients in China with HCC has not been determined. This study was designed to determine the optimal staging system for predicting patient prognosis by comparing the performances of these four staging systems in a cohort of Chinese patients with HCC. METHODS: This study enrolled 307 consecutive Chinese patients with HCC in Shandong Province. The performances of the CS, TNM, BCLC, and CLIP staging systems were compared and ranked using a concordance index. Predictors of survival were identified using univariate and multivariate Cox model analyses. RESULTS: The mean overall survival of the patient cohort was 12.08 ± 11.87 months. Independent predictors of survival included tumor size, number of lesions, tumor thromboses, cirrhosis, serum albumin level and serum total bilirubin level. Compared with the other three staging systems, the CS staging system showed optimal performance as an independent predictor of patient survival. The BCLC staging system showed the poorest performance; its treatment algorithm was not suitable for patients in this study. CONCLUSIONS: CS was the most suitable staging system for predicting survival of patients with HCC in China.

MiR-214 increases the sensitivity of breast cancer cells to tamoxifen and fulvestrant through inhibition of autophagy.

BACKGROUND: Tamoxifen (TAM) and fulvestrant (FUL) are the major drugs for patients with estrogen receptor-positive (ER(+)) breast cancers. However, the development of endocrine resistance is the impediment for successful treatment. We aimed to explore the mechanisms of endocrine resistance and therapeutic strategy for overcoming resistance against TAM and FUL. METHODS: Experiments were performed in ER(+) and estrogen/TAM-sensitive MCF7 cells and antiestrogen-resistant MCF7/LCC9 cells. The expression of miR-214 and uncoupling protein 2 (UCP2) was determined by RT-qPCR and Western blot in breast cancer cells and human breast cancer tissue specimens. Cell autophagy was examined by fluorescent probe monodansyl cadaverine (MDC) and GFP-LC3-II-positive punctate identified by confocal microscopy. Apoptotic cells were determined by Annexin V-FITC/PI staining. The potential regulatory target of miR-214 was determined by prediction tool, target protein expression and luciferase reporter assay. RESULTS: 4-OHT/FUL treatment resulted in induction of apoptosis as well as autophagy in breast cancer cells. Autophagy might be the major cause of endocrine resistance to 4-OHT or FUL. MiR-214 increased the sensitivity of breast cancer cells to the 4-OHT/FUL-induced apoptosis through inhibition of autophagy. Importantly, a negative correlation was established between miR-214 and UCP2 in human breast cancer tissue specimens assayed by RT-qPCR. UCP2 was identified to be a direct target of miR-214. Further study in MCF7/LCC9 cells indicated that endocrine resistance might arise from activation of the PI3K-Akt-mTOR pathway, thereby inducing autophagy by overexpression of UCP2. CONCLUSION: MiR-214 increased the sensitivity of breast cancer cells to TAM and FUL through inhibition of autophagy by targeting UCP2. MiR-214 shows potential as a novel therapeutic strategy for overcoming endocrine resistance in ER(+) breast cancers.

Suppression of toll-like receptor 2 expression inhibits the bioactivity of human hepatocellular carcinoma.

Toll-like receptor (TLR) 2 signaling is regarded as one of the mechanisms of chronic inflammation, but it can also mediate tumor cell immune escape and tumor progression. However, the role of TLR2 in the progression of human hepatocellular carcinoma (HCC) remains unclear. The objective of the study was to examine the effect of TLR2 on the bioactivity of HCC cell lines, HepG2 and BEL-7402, and the relationship between high mobility group box1 (HMGB1) and TLR2. The expression of TLR2 and nuclear factor-kappaB/P65 (NF-κB/P65) in HepG2 and BEL-7402 was assayed by Western blot. Cells were transfected with specific small interfering RNAs of TLR2 (TLR2-siRNAs), then TLR2-siRNA-transfected cells were treated with recombinant HMGB1 (rHMGB1). Apoptosis was determined by flow cytometry. Results showed that TLR2 was expressed in HepG2 and BEL-7402 cells. The ability of proliferation, invasion, and migration in siRNA group was lower than that in blank group, and the apoptosis ratio was higher than that in blank group, respectively. NF-κB/P65 expression was declined in contrast with blank group. Downregulation of TLR2 by siRNA resulted in a significant inhibition of proliferation, invasion, migration, and NF-κB/P65 expression, and elevated apoptotic ratio. Conversely, rHMGB1 promoted proliferation, invasion, and migration, induced NF-κB/P65 expression, and inhibited cells apoptosis. Furthermore, downregulation of TLR2 weakened the role of rHMGB1. This study suggests TLR2 and HMGB1 are important targets for therapeutic intervention of HCC.

A promising approach of overcoming the intrinsic resistance of Candida krusei to fluconazole (FLC)--combining tacrolimus with FLC.

Candida krusei is intrinsically resistant to fluconazole (FLC). This study aimed to investigate whether tacrolimus (FK506) could enhance the susceptibility of FLC against C. krusei. The tested strains included the following: five isolates with minimal inhibitory concentration (MIC) of 32 µg mL(-1), two with MIC of 256 µg mL(-1), and one with MIC of 512 µg mL(-1). MICs of FK506 and FLC alone and in combination were determined by checkerboard assay, with data analyzed by fractional inhibitory concentration index model. The time-kill curves were plotted to investigate the antifungal activity at 0, 6, 12, 24, and 48 h after drug exposure. The results revealed that FK506 reduced the resistance of all isolates obviously and degree of reduction in MICs varied with susceptibilities of strains. Addition of FK506 resulted in a fourfold and 16-fold downward shift in MICs of the isolates with MICs of 32 µg mL(-1) and of ≥ 256 µg mL(-1), respectively. The synergy was further confirmed by the time-kill assay. When they were in combination against CK4/CK9 with MIC of 32/256 µg mL(-1), there was a 2.25/2.03 log10 CFU mL(-1) decrease at 24 h compared with FLC alone, respectively. In conclusion, combination of FK506 and FLC may represent a promising approach of overcoming the intrinsic resistance of C. krusei to FLC.

Multifunctional Hydrogels Based on γ-Polyglutamic Acid/Polyethyleneimine for Hemostasis and Wound Healing.

Current hemostatic materials have many shortcomings, such as biotoxicity or poor degradability, and do not effectively promote wound healing after hemostasis. To address these limitations, a hemostasis-promoting wound-healing hydrogel, polyglutamic acid/polyethyleneimine/montmorillonite (PPM), comprising polyglutamic acid, 3,4-dihydroxybenzaldehyde-modified polyethyleneimine, and amino-modified montmorillonite (montmorillonite-NH2) was constructed in this study. Due to the excellent water absorption abilities of γ-polyglutamic acid, the PPM and polyglutamic acid/polyethyleneimine hydrogels could rapidly absorb the blood and tissue fluid exuded from the wound to keep the wound clean and accelerate the blood coagulation. The homogeneous distribution of montmorillonite-NH2 enhanced not only the mechanical properties of the hydrogel but also its hemostatic properties. In addition, the modification of polyethylenimine with 3,4-dihydroxybenzaldehyde provided anti-inflammatory effects and endorsed the wound healing. Cellular and blood safety experiments demonstrated the biocompatibility of the PPM hydrogel, and animal studies demonstrated that the PPM hydrogel effectively stopped bleeding and promoted wound healing. The concept design of clay-based hydrogel may create diverse opportunities for constructing hemostasis and wound-healing dressings.

Penetration enhancers strengthen tough hydrogel bioadhesion and modulate locoregional drug delivery.

The human body possesses natural barriers, such as skin and mucosa, which limit the effective delivery of therapeutics and integration of medical devices to target tissues. Various strategies have been deployed to breach these barriers mechanically, chemically, or electronically. The development of various penetration enhancers (PEs) offers a promising solution due to their ability to increase tissue permeability using readily available reagents. However, existing PE-mediated delivery methods often rely on weak gel or liquid drug formulations, which are not ideal for sustained local delivery. Hydrogel adhesives that can seamlessly interface biological tissues with controlled drug delivery could potentially resolve these issues. Here, we demonstrate that tough adhesion between drug-laden hydrogels and biological tissue (e.g. skin and tumours) can lead to effective local delivery of drugs deep into targeted tissues by leveraging the enhanced tissue penetration mediated by PEs. The drug release profile of the hydrogel adhesives can be fine-tuned by further engineering the nanocomposite hydrogel matrix to elute chemotherapeutics from 2 weeks to 2 months. Using a 3D tumour spheroid model, we demonstrated that PEs increased the cancer-killing effectiveness of doxorubicin by facilitating its delivery into tumour microtissues. Therefore, the proposed tough bioadhesion and drug delivery strategy modulated by PEs holds promise as a platform technique to develop next-generation wearable and implantable devices for cancer management and regenerative medicine.

Construction and validation of four-metabolism related-long non-coding RNAs as potential signature in prognosis of colon cancer.

Background: Emerging evidence suggests that metabolism plays important roles in the initiation and progression of colon cancer (CC) and the outcomes of CC patients. Long non-coding RNAs (lncRNA) are key regulators of regulatory molecules linking to a wide variety of cancer cellular functions. This study aims to develop a metabolic lncRNA signature to help better predict prognosis for CC patients. Methods: In the current study, the transcriptome data and clinical data of CC was downloaded from The Cancer Genome Atlas (TCGA). Metabolism-related gene sets were downloaded from the Molecular Signatures Database (MSigDB). Differential lncRNAs related to metabolism was obtained by performing the correlations between differential expression profile of metabolic genes and lncRNAs. To construct a prognostic model of CC based on metabolism-related lncRNAs, we divided patients, whose clinical data were available, into a training set and a validation set at a ratio of 7:3. The prognostic metabolism related-lncRNA signature was established using the training set by univariate and multivariate Cox regression analysis, and the validation set was used to test the capacity of the prognostic model. The correlation between risk score and clinicopathological features, immune function GO and KEGG analysis was investigated using the entire set. Finally, GSEA pathway enrichment analysis was carried out on the entire set samples for the high- and low- risk groups. Results: We identified 604 differential lncRNAs and 252 genes related to metabolism. After univariate and multivariate Cox regression analysis, four lncRNAs were finally identified to build a signature, which was verified the effectiveness by the TCGA validation set. The multivariate Cox regression analysis showed that the risk score, age of diagnosis and T stage were independent prognostic factor for CC patients. It is shown that some immunopathogenesis, GO items and KEGG pathways demonstrated difference between high- and low- risk group. Conclusions: We developed a four-metabolism related-lncRNA signature for prognostic prediction of CC, which may help select high-risk subpopulation patients who require more aggressive therapy or intervention.

Identification of a pyrone-type species as the active site for the oxygen reduction reaction.

A bicyclic pyrone-type species on oxygen-doped carbon catalysts was identified as the active site for the oxygen reduction reaction in acidic solution. It has much higher activity than that of typical nitrogen-doped carbon catalysts (0.219 e s-1 site-1vs. 0.021-0.088 e s-1 site-1 at 0.6 VRHE). The ortho-carbon atom in the carbonyl ring of the pyrone-type species was revealed as the reactive site by theoretical calculations.

Pharmacist-Led Management Improves Treatment Adherence and Quality of Life in Opioid-Tolerant Patients With Cancer Pain: A Randomized Controlled Trial.

INTRODUCTION: Opioid-tolerant patients are more likely to deviate from recommended treatments and to experience inadequate analgesia than opioid-naive ones. The aim of this study was to examine whether pharmacist-led management could help improve treatment adherence and quality of life. METHODS: Eligible patients were randomized in a 1:1 ratio to control group and intervention group. The control group received routine education and support, while the intervention group received additional individualized pharmacist-led care. The primary endpoint was treatment adherence in the per-protocol analysis, as evaluated by blinded assessors. An interim analysis was planned when 30% patients completed the study. Alpha was divided into the interim analysis (0.015) and the final analysis (0.035). RESULTS: In the interim analysis (97 and 87 patients in the control and intervention groups, respectively), the primary endpoint was met. Pharmacist-led intervention significantly increased treatment adherence (93.3 vs. 79.8%; OR: 2.25; 95% CI 1.02, 4.94; P = 0.013), quality of life (0.81 ± 0.17 vs. 0.72 ± 0.25; P = 0.008), and reporting of adverse events (82.7 vs. 61.9%; OR: 1.88; 95% CI 1.16, 3.07; P = 0.004). The two groups did not differ in pain control rate (66.7 vs. 57.1%; OR: 1.25; 95% CI 0.87, 1.78; P = 0.218), breakthrough pain-free rate (66.7 vs. 61.9%; OR: 1.12; 95% CI 0.78, 1.59; P = 0.532) and pain score (1.97 ± 1.04 vs. 2.15 ± 1.24; P = 0.522). CONCLUSIONS: Pharmacist-led management improved treatment adherence, quality of life, and the reporting of adverse events in opioid-tolerant patients with cancer pain. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03455023.

[Clinical Analysis of Docetaxel Combined with PD-1/PD-L1 Inhibitor in Second-line Treatment of Advanced Non-small Cell Lung Cancer].

BACKGROUND: Programmed cell death 1 or programmed cell death ligand 1 inhibitor (PD-1/PD-L1 inhibitor) and docetaxel, as the standard second-line treatments of advanced non-small cell lung cancer (NSCLC) patients, have limited effects. There are few studies on whether docetaxel combined with PD-1/PD-L1 inhibitor can increase the efficacy and make patients better benefit. The aim of this study is to evaluate the efficacy and safety of docetaxel combined with PD-1/PD-L1 inhibitor for the second-line treatment of stage IV NSCLC patients. METHODS: Stage IV NSCLC patients (n=118) who received treatment at Shandong Cancer Hospital between October 1, 2018, and December 31, 2020, were retrospectively analyzed. They were divided into observation group (n=69) and control group (n=49) according to different treatment plan. Observation group was given docetaxel plus PD-1/PD-L1 inhibitor, while control group was given PD-1/PD-L1 inhibitor. The clinical curative effect and the incidence of adverse reactions of grade 3 and above were compared between the two groups. RESULTS: The disease control rate (DCR) was higher in the observation group (89.9%) than that in the control group (73.5%) (P=0.019), and the objective response rate (ORR) showed no significant difference between observation group (24.6%) and control group (16.3%) (P=0.276). Till June 22, 2021, the 1-year PFS rate showed no difference between observation group (16.5%) and control group (7.7%) (P=0.205). During the treatment period, the adverse reactions of the two groups were mostly grade 1 to 2, and could be tolerated. The incidence of bone marrow suppression in observation group was higher than that in the control group (P<0.05), and the remaining adverse reactions were not statistically different from control group. Cox regression analysis showed that performance status (PS) (P=0.020) and age (P=0.049) were independent prognostic factors for the effect of docetaxel combined with PD-1/PD-L1 inhibitor. CONCLUSIONS: The second-line treatment with docetaxel plus PD-1/PD-L1 inhibitor in patients with stage IV NSCLC can improve the DCR and prolong the PFS, and the adverse reactions are tolerable.

Arsenic sulfide reverses cisplatin resistance in non-small cell lung cancer in vitro and in vivo through targeting PD-L1.

BACKGROUND: Recent studies have found that programmed death ligand 1 (PD-L1) might be involved in chemotherapy resistance in non-small cell lung cancer (NSCLC). Arsenic sulfide (As4 S4 ) has been recognized to have antitumor activities and enhance the cytotoxic effect of chemotherapy drugs. In this study, we aimed to verify the relationship between PD-L1 and cisplatin (DDP) resistance and identify whether As4 S4 could reverse DDP resistance through targeting PD-L1 in NSCLC. METHODS: The effect of As4 S4 and DDP on cell proliferation and apoptosis was investigated in NSCLC cell lines. The expression of p53 and PD-L1 proteins was measured by western blotting analysis. The levels of miR-34a-5p, miR-34a-3p and PD-L1 in cells were measured by real-time qPCR analysis. Mouse xenograft models were established by inoculation with A549/DDP (DDP-resistant) cells. RESULTS: Depletion of PD-L1 inhibited DDP resistance in A549/DDP and H1299/DDP cells. As4 S4 was capable of sensitizing A549/DDP cells to DDP by enhancing apoptosis. As4 S4 upregulated p53 expression and downregulated PD-L1 expression in A549/DDP cells. As4 S4 increased miR-34a-5p level in A549/DDP cells. Inhibition of p53 by PFT-α partially restored the levels of PD-L1 and miR-34a-5p. Pretreatment with PFT-α suppressed the apoptosis rate induced by cotreatment of As4 S4 and DDP in A549/DDP cells. Cotreatment of DDP and As4 S4 notably reduced the tumor size when compared with DDP treatment alone in vivo. CONCLUSIONS: Upregulation of PD-L1 was correlated with DDP resistance in NSCLC cells. Mechanistic analyses indicated that As4 S4 might sensitize NSCLC cells to DDP through targeting p53/miR-34a-5p/PD-L1 axis.

Reversal of azole resistance in Candida albicans by oridonin.

OBJECTIVES: Candida albicans is a yeast that causes fungal infections with high mortality and is typically resistant to azole drugs. To overcome this resistance, we explored the combined use of oridonin (ORI) and three azole drugs, namely fluconazole (FLC), itraconazole (ITR) and voriconazole (VOR). Azole-resistant C. albicans strains were obtained from cancer patients and the reversal of drug resistance in these strains was investigated. METHODS: The synergistic antifungal activity of ORI and azole drugs was measured by checkerboard microdilution and time-kill assays. The resistance reversal mechanisms, namely inhibition of drug efflux and induction of apoptosis, were investigated by flow cytometry. Expression levels of the efflux pump-related genesCDR1 and CDR2 were assessed by RT-qPCR. RESULTS: The efflux pump inhibition assay with ORI showed that the minimum inhibitory concentrations (MICs) of FLC (128-fold), ITR (64-fold) and VOR (250-fold) decreased significantly. Upregulation of genes encodingCDR1 and CDR2 was confirmed in the resistant strain. The sensitising effect of ORI on FLC in the treatment of C. albicans also included the promotion of apoptosis. CONCLUSION: We demonstrated that combining azoles with ORI exerted potent synergism and that ORI could promote sensitisation to azoles in azole-resistantC. albicans. The discovery that ORI can effectively inhibit drug efflux and promote apoptosis may provide new insights and therapeutic strategies to overcome increasing azole resistance in C. albicans.

A novel use for an old drug: resistance reversal in Candida albicans by combining dihydroartemisinin with fluconazole.

Aim: To investigate the effects of dihydroartemisinin combined with fluconazole against C. albicans in vitro and to explore the underlying mechanisms. Materials & methods: Checkerboard microdilution assay and time-kill curve method were employed to evaluate the static and dynamic antifungal effects against C. albicans. Reactive oxygen species (ROS) was measured by a fluorescent probe. Results: Combination of dihydroartemisinin and fluconazole exerted potent synergy against planktonic cells and biofilms of fluconazole-resistant C. albicans, with the fractional inhibitory concentration index values less than 0.07. A potent fungistatic activity of this drug combination could still be observed after 18 h. The accumulation of ROS induced by the drug combination might contribute to the synergy. Conclusion: Dihydroartemisinin reversed the resistance of C. albicans to fluconazole.

Lay abstract Patients with weakened immune system often suffer from C. albicans infections. C. albicans is a common fungus. Fluconazole is a widely used antifungal drug owing to its low price and few side effects. Unfortunately, fluconazole is gradually losing its effect against C. albicans due to the constantly emerging resistance in C. albicans. Interestingly, in this study a combined use of fluconazole and an old antimalarial agent restored the effect of fluconazole against resistant C. albicans. The antimalarial drug we used is dihydroartemisinin, with low price, high safety and multiple biological activities, which originates from a traditional Chinese medicine. Our study also presented that this drug combination generated abundant reactive oxygen, which might account for the effect. The drug combination would be expected to be used for treating C. albicans infections.

The combination of minocycline and fluconazole causes synergistic growth inhibition against Candida albicans: an in vitro interaction of antifungal and antibacterial agents.

Combination therapy can be used for the treatment of fungal infections, especially for those caused by antifungal-resistant fungi. In the present study, in vitro interactions and mechanisms between fluconazole and minocycline against Candida albicans were evaluated. The nature of the interactions determined by spectrophotometric method in a checkerboard assay was interpreted using nonparametric models of fractional inhibitory concentration index (FICI) and percentages of growth difference (ΔE). In the mechanism study, we evaluated the potential activity of minocycline on fluconazole penetrating the C. albicans biofilm. Furthermore, the effect of fluconazole and minocycline alone and in combination on the cellular calcium balance, as well as on the uptake and efflux of fluconazole were evaluated. It was found that fluconazole can work synergistically with minocycline against fluconazole-resistant C. albicans; the minimum inhibitory concentration of fluconazole decreased from 512 to 2 microgmL(-1) when fluconazole and minocycline were given in combination, with an FICI of 0.035 and 0.064 and high-percentage synergistic interactions of 1250% and 988% for the two resistant strains. The mechanism of action was suggested to be the enhancement of minocycline on fluconazole penetrating biofilm, and inducing the intracellular calcium release, instead of impacting on the uptake and efflux of fluconazole. Our results suggest that the combination of fluconazole and minocycline can reduce the fluconazole resistance of C. albicans in vitro.

Differences in terms of presentation and outcomes between patients with lung cancer as opposed to other solid organ cancer after infection with SARS-CoV-2: protocol for a systematic review.

INTRODUCTION: Scholars believe that COVID-19 can be particularly lethal for patients with cancer. Some studies found that COVID-19 appears to be more lethal in patients with lung cancer than in other cancer patients. In order to take appropriate measures to balance a delay in lung cancer treatment against the risk for a potential COVID-19 exposure, we first need to know whether patients with lung cancer have special risks. We aim to conduct a systematic review and meta-analysis to examine differences in terms of presentation and outcomes between patients with lung cancer as opposed to other solid organ cancer after infection with SARS-CoV-2. METHODS AND ANALYSIS: A comprehensive search of published original research studies will be performed in Embase, MEDLINE, Web of Science, WangFangData, CQVIP, COMPENDEX and CNKI. The medRxiv preprint server will also be searched for applicable studies (grey literature). Original research studies will be included if they include patients with: (A) laboratory-confirmed SARS-CoV-2 infection and (B) confirmed solid cancer, and (C) measurable clinical presentation or outcome, such as mortality rate, intensive care unit admission rate, incidence of pneumonia. One author will conduct the electronic database searches, two authors will independently screen studies, two will extract data and two will assess study quality. If I² exceeds 60% for the pooled analysis, we will explore sources of heterogeneity in subgroups of studies. We will use fixed-effect, random-effects or mixed-effects models to estimate the relative risk or OR. If the data reporting allows, a subgroup analysis between non-small cell lung cancer and small cell lung cancer patients will be performed. ETHICS AND DISSEMINATION: The proposed study will not collect individual-level data and, therefore, does not require ethical approval. We will submit our findings to a peer-reviewed scientific journal and will disseminate results through presentations at international scientific conferences. PROSPERO REGISTRATION NUMBER: CRD42020190118.

Validated LC-MS/MS method of Sphingosine 1-phosphate quantification in human serum for evaluation of response to radiotherapy in lung cancer.

BACKGROUND: Sphingosine 1-phosphate (S1P), a bioactive lipid, has been shown to mediate cancer processes. Therefore, accurate qualitative and quantitative determination is essential. The current assay method is still cumbersome to be of practical use worldwide and the aim of this study was therefore to develop a fast, accurate, precise and efficient LC-MS/MS method for targeted analyses of S1P in serum samples. METHODS: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is an established method used for monitoring and analyzing S1P levels in serum. We determined the level of serum S1P in 256 patients with lung cancer and 36 healthy donors, and used Spearman';s rank correlation analysis to evaluate the difference in serum S1P levels between radiotherapy and nonradiotherapy patients. RESULTS: Standard curves were linear over ranges of 25-600 ng/mL for S1P with correlation coefficient (r2 ) greater than 0.9996. The lower limit of quantifications (LLOQs) was 25 ng/mL. The intra- and interbatch precisions and accuracy was less than 10% for S1P. The recoveries of the method were found to be 80%-98%. Serum S1P levels in healthy donors were different from those in patients (P < 0.001). Of 256 lung cancer patients, 124 (48.4%) received radiotherapy and were identified to have concomitant low serum S1P levels (222.13 ± 48.63), whereas 132 (51.6%) who had not received radiotherapy were identified to have high levels (315.16 ± 51.06). The serum S1P levels were therefore associated with radiotherapy (Spearman's Rho = -0.653, P < 0.001). CONCLUSIONS: Our results indicated that this new LC-MS/MS method is rapid, sensitive, specific and reliable for the quantification of S1P levels in serum samples. The level of S1P in serum samples of patients with lung cancer who received radiotherapy was significantly lower than that in patients who did not receive radiotherapy. KEY POINTS: An improved method was established to quantify S1P levels in human serum by LC-MS/MS, which enabled the change in serum S1P levels in lung cancer patients to be monitored, in combination with radiotherapy, and their clinical significance to be analyzed.

SphK2 confers 5-fluorouracil resistance to colorectal cancer via upregulating H3K56ac-mediated DPD expression.

Aberrant sphingolipid metabolism has been implicated in chemoresistance, but the underlying mechanisms are still poorly understood. Herein we revealed a previously unrecognized mechanism of 5-fluorouracil (5-FU) resistance contributed by high SphK2-upregulated dihydropyrimidine dehydrogenase (DPD) in colorectal cancer (CRC), which is evidenced from human CRC specimens, animal models, and cancer cell lines. TMA samples from randomly selected 60 CRC specimens firstly identified the clinical correlation between high SphK2 and increased DPD (p < 0.001). Then the regulatory mechanism was explored in CRC models of villin-SphK2 Tg mice, SphK2-/-mice, and human CRC cells xenografted nude mice. Assays of ChIP-Seq and luciferase reporter gene demonstrated that high SphK2 upregulated DPD through promoting the HDAC1-mediated H3K56ac, leading to the degradation of intracellular 5-FU into inactive α-fluoro-ß-alanine (FBAL). Lastly, inhibition of SphK2 by SLR080811 exhibited excellent inhibition on DPD expression and potently reversed 5-FU resistance in colorectal tumors of villin-SphK2 Tg mice. Overall, this study manifests that SphK2high conferred 5-FU resistance through upregulating tumoral DPD, which highlights the strategies of blocking SphK2 to overcome 5-FU resistance in CRC.