Multidrug resistance transporters P-gp and BCRP limit the efficacy of ATR inhibitor ceralasertib in cancer cells.

The therapeutic effect of chemotherapy and targeted therapy are known to be limited by drug resistance. Substantial evidence has shown that ATP-binding cassette (ABC) transporters P-gp and BCRP are significant contributors to multidrug resistance (MDR) in cancer cells. In this study, we demonstrated that a clinical-staged ATR inhibitor ceralasertib is susceptible to P-gp and BCRP-mediated MDR. The drug resistant cancer cells were less sensitive to ceralasertib compared to the parental cells. Moreover, ceralasertib resistance can be reversed by inhibiting the drug efflux activity of P-gp and BCRP. Interestingly, ceralasertib was able to downregulate the level of P-gp but not BCRP, suggesting a potential regulation between ATR signaling and P-gp expression. Furthermore, computational docking analysis predicted high affinities between ceralasertib and the drug-binding sites of P-gp and BCRP. In summary, overexpression of P-gp and BCRP are sufficient to confer cancer cells resistance to ceralasertib, underscoring their role as biomarkers for therapeutic efficacy.

A Novel Grading System for Diffuse Chorioretinal Atrophy in Pathologic Myopia.

INTRODUCTION: This study aims to quantitatively assess diffuse chorioretinal atrophy (DCA) in pathologic myopia and establish a standardized classification system utilizing artificial intelligence. METHODS: A total of 202 patients underwent comprehensive examinations, and 338 eyes were included in the study. The methodology involved image preprocessing, sample labeling, employing deep learning segmentation models, measuring and calculating the area and density of DCA lesions. Lesion severity of DCA was graded using statistical methods, and grades were assigned to describe the morphology of corresponding fundus photographs. Hierarchical clustering was employed to categorize diffuse atrophy fundus into three groups based on the area and density of diffuse atrophy (G1, G2, G3), while high myopic fundus without diffuse atrophy was designated as G0. One-way analysis of variance (ANOVA) and nonparametric tests were conducted to assess the statistical association with different grades of DCA. RESULTS: On the basis of the area and density of DCA, the condition was classified into four grades: G0, G1 (0 < density ≤ 0.093), G2 (0.093 < density ≤ 0.245), and G3 (0.245 < density ≤ 0.712). Fundus photographs depicted a progressive enlargement of atrophic lesions, evolving from punctate-shaped to patchy with indistinct boundaries. DCA atrophy lesions exhibited a gradual shift in color from brown-yellow to yellow-white, originating from the temporal side of the optic disc and extending towards the macula, with severe cases exhibiting widespread distribution throughout the posterior pole. Patients with DCA were significantly older [34.00 (27.00, 48.00) vs 29.00 (26.00, 34.00) years], possessed a longer axial length (28.85 ± 1.57 vs 27.11 ± 1.01 mm), and exhibited a more myopic spherical equivalent [- 13.00 (- 16.00, - 10.50) vs - 9.09 ± 2.41 D] compared to those without DCA (G0) (all P < 0.001). In eyes with DCA, a trend emerged as grades increased from G1 to G3, showing associations with older age, longer axial length, deeper myopic spherical equivalent, larger area of parapapillary atrophy, and increased fundus tessellated density (all P < 0.001). CONCLUSIONS: The novel grading system for DCA, based on assessments of area and density, serves as a reliable measure for evaluating the severity of this condition, making it suitable for widespread application in the screening of pathologic myopia.

Cognitive impairment associated with cerebellar volume loss in spinocerebellar ataxia type 3.

BACKGROUND: Many neuroscience and neurology studies have forced a reconsideration of the traditional motor-related scope of cerebellar function, which has now expanded to include various cognitive functions. Spinocerebellar ataxia type 3 (SCA3; the most common hereditary ataxia) is neuropathologically characterized by cerebellar atrophy and frequently presents with cognitive impairment. OBJECTIVE: To characterize cognitive impairment in SCA3 and investigate the cerebellum-cognition associations. METHODS: This prospective, cross-sectional cohort study recruited 126 SCA3 patients and 41 healthy control individuals (HCs). Participants underwent a brain 3D T1-weighted images as well as neuropsychological tests. Voxel-based morphometry (VBM) and region of interest (ROI) approaches were performed on the 3D T1-weighted images. CERES was used to automatically segment cerebellums. Patients were grouped into cognitively impaired (CI) and cognitively preserved (CP), and clinical and MRI parameters were compared. Multivariable regression models were fitted to examine associations between cerebellar microstructural alterations and cognitive domain impairments. RESULTS: Compared to HCs, SCA3 patients showed cognitive domain impairments in information processing speed, verbal memory, executive function, and visuospatial perception. Between CI and CP subgroups, the CI subgroup was older and had lower education, as well as higher severity scores. VBM and ROI analyses revealed volume loss in cerebellar bilateral lobule VI, right lobule Crus I, and right lobule IV of the CI subgroup, and all these cerebellar lobules were associated with the above cognitive domain impairments. CONCLUSIONS: Our findings demonstrate the multiple cognitive domain impairments in SCA3 patients and indicate the responsible cerebellar lobules for the impaired cognitive domain(s).

Fundus Tessellated Density of Pathologic Myopia.

PURPOSE: The study aimed to quantitatively evaluate the fundus tessellated density (FTD) in different categories of pathologic myopia (PM) using fundus photographs with the application of artificial intelligence. METHODS: A retrospective review of 407 PM (META-PM, Category 2-Category 4) eyes was conducted, employing a biomimetic mechanism of human vision and integrated image processing technologies for FTD extraction and calculation. Different regions of interest were analyzed, including circle O4.5 (optic disc centered, diameter of 4.5 mm) and circle M1.0, M3.0, M6.0 (macular centered, diameter of 1.0, 3.0, and 6.0 mm), using 2 partitioning methods ("X" and "+"). The density of patchy (Category 3) or macular atrophy (Category 4) areas was quantified. Univariate and multivariate linear regression analyses were performed to assess the association with FTD. RESULTS: The mean FTD of total PM eyes was 0.283, ranging from 0.002 to 0.500, and demonstrating a negative correlation with the PM category. In multivariate analysis, age was found to be significantly associated with FTD ( P <0.05), while axial length did not show a significant association. Fundus tessellation of circle O4.5 and circle M6.0 displayed associations with the FTD across different PM categories. The "X" partitioning method better fit the circle M6.0 region, while both methods were suitable for the circle O4.5 region. After excluding the patchy and macular atrophic areas, the mean FTD values were 0.346 in Category 2, 0.261 in Category 3, and 0.186 in Category 4. CONCLUSIONS: The study revealed a decreasing trend in FTD values across different categories of PM, regardless of the presence or absence of patchy or macular atrophic areas. Quantifying FTD in PM could be a valuable tool for improving the existing PM classification system and gaining insights into the origin of posterior staphyloma and visual field defects in high myopia.

Clinical Features of Fundus Tessellation and Its Relationship with Myopia: A Systematic Review and Meta-analysis.

INTRODUCTION: This study aims to assess the existing literature on fundus tessellation (FT), focusing on its prevalence, associated factors, distribution, and progression. METHODS: Systemic methods were employed to search and gather published literature on FT from databases such as the National Library of Medicine (PubMed), Web of Science (WOS), and Elsevier on July 1, 2023. The quality of the studies was evaluated using the Newcastle-Ottawa Scale (NOS) and the Healthcare Research and Quality (AHRQ) criteria. A meta-analysis was conducted to compare tessellated and normal fundus with respect to age, gender, axial length, and spherical equivalent. RESULTS: The systematic review included 23 articles, encompassing a total of 3053 eyes in the meta-analysis. The prevalence of FT varied from 43.00 to 94.35%. The severity of FT was significantly associated with older age, male sex, lower body weight index, longer axial length, larger peripapillary atrophy, thinner choroid, thinner sclera, and larger corneal radius of curvature, suggesting a potential progression pattern. Notably, FT was observed predominantly in the macular and peripapillary regions. The meta-analysis revealed that tessellated fundus tended to be associated with older age (mean difference [MD] 4.76, 95% confidence interval [CI] 1.71-7.80, P < 0.01), longer axial length (MD 0.86, 95% CI 0.70-1.02, P < 0.01), and a lower spherical equivalent (MD - 1.16, 95% CI - 1.68 to 0.65, P < 0.01) compared to normal fundus. However, there was no significant difference in the proportion of males between individuals with tessellated and normal fundus (odds ratio [OR] 1.12, 95% CI 0.89-1.42, P = 0.32). CONCLUSIONS: Overall, this systematic review and meta-analysis shed light on the prevalence, characteristics, and factors associated with FT, offering valuable insights for clinicians and researchers in the field of ophthalmology. STUDY REGISTRATION: The study protocol was registered on the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023442486).

Illness anxiety, infertility stress, resilience and thyroid-stimulating hormone among infertile people undergoing ART treatment in China.

OBJECTIVE: Infertile people undergoing assisted reproductive technology (ART) treatment in China may experience severe infertility-related stress and illness anxiety (IA). However, little relevant research has been conducted until now. DESIGN: This study investigated the IA of 340 infertile people undergoing ART treatment, including 43 males, 292 females and 5 who preferred not to answer, in 2 tertiary general public hospitals in Wen Zhou, China. MAIN OUTCOME MEASURES: Blood samples for thyroid-stimulating hormone (TSH) levels were obtained from 107 women to explore the relationship between IA and TSH. The questionnaire contained the Mandarin version of the Fertility Problem Inventory, the Resilient Trait Scale for Chinese Adults and the Whiteley Index, measuring infertility stress, resilience and IA, respectively. RESULTS: An incidence rate of 44.1% of IA among infertile people undergoing ART treatment in China was determined, and 30.2% of men and 46.6% of women had severe IA (χ2 = 4.05, p < 0.05). The risk of severe IA in women was around twice that in men (OR = 2.01, 95% CI: 1.01-4.01). Women's IA level was significantly associated with their TSH level (ß = 0.27, p < 0.01). Resilience played a moderating role in the relationship between parenthood importance and illness anxiety. CONCLUSION: This study highlighted the importance and urgency of providing holistic care for illness anxiety of infertile people undergoing ART treatment in China, especially women. The findings of this study indicated that mind-body therapies and resilience empowerment workshops could be conducive to infertile people's holistic health.

Association of lung-intestinal microecology and lung cancer therapy.

In recent years, the incidence of lung cancer is increasing. Lung cancer has become one of the most malignant tumors with the highest incidence in the world, which seriously affects people's health. The most important cause of death of lung cancer is metastasis. Therefore, it is crucial to understand the mechanism of lung cancer progression and metastasis. This review article discusses the physiological functions, pathological states and disorders of the lung and intestine based on the concepts of traditional Chinese medicine (TCM), and analyzes the etiology and mechanisms of lung cancer formation from the perspective of TCM. From the theory of "the exterior and interior of the lung and gastrointestinal tract", the theory of "the lung-intestinal axis" and the progression and metastasis of lung cancer, we proposed e "lung-gut co-treatment" therapy for lung cancer. This study provides ideas for studying the mechanism of lung cancer and the comprehensive alternative treatment for lung cancer patients.

CAR T cells: engineered immune cells to treat brain cancers and beyond.

Malignant brain tumors rank among the most challenging type of malignancies to manage. The current treatment protocol commonly entails surgery followed by radiotherapy and/or chemotherapy, however, the median patient survival rate is poor. Recent developments in immunotherapy for a variety of tumor types spark optimism that immunological strategies may help patients with brain cancer. Chimeric antigen receptor (CAR) T cells exploit the tumor-targeting specificity of antibodies or receptor ligands to direct the cytolytic capacity of T cells. Several molecules have been discovered as potential targets for immunotherapy-based targeting, including but not limited to EGFRvIII, IL13Rα2, and HER2. The outstanding clinical responses to CAR T cell-based treatments in patients with hematological malignancies have generated interest in using this approach to treat solid tumors. Research results to date support the astounding clinical response rates of CD19-targeted CAR T cells, early clinical experiences in brain tumors demonstrating safety and evidence for disease-modifying activity, and the promise for further advances to ultimately assist patients clinically. However, several variable factors seem to slow down the progress rate regarding treating brain cancers utilizing CAR T cells. The current study offers a thorough analysis of CAR T cells' promise in treating brain cancer, including design and delivery considerations, current strides in clinical and preclinical research, issues encountered, and potential solutions.

Nivolumab and relatlimab for the treatment of melanoma.

Melanoma is a highly lethal type of skin cancer. Although an early diagnosis, in combination with surgery for nonmetastatic melanomas, significantly increases the probability of survival, there are no efficacious treatments for metastatic melanoma. Nivolumab and relatlimab are monoclonal antibodies that selectively interact with and block the proteins programmed cell death protein 1 (PD-1) and lymphocyte activation protein 3 (LAG-3), respectively, and thus, their activation by their cognate ligands. The combination of these immunotherapy drugs was approved in 2022 by the United States Food and Drug Administration (FDA) for the treatment of melanoma. Data from clinical trials indicated that, compared to nivolumab monotherapy, nivolumab and relatlimab produced more than a 2-fold median increase in progression-free survival (PFS) and a higher response rate in melanoma patients. This is an important finding as the response of patients to immunotherapies is limited due to dose-limiting toxicities and secondary drug resistance. This review article will discuss the pathogenesis of melanoma and the pharmacology of nivolumab and relatlimab. In addition, we will provide i) a summary of the anticancer drugs that inhibit LAG-3 and PD-1 in cancer patients and ii) our perspective about the use of nivolumab in combination with relatlimab to treat melanoma.

Association between malnutrition risk and hemorrhagic transformation in patients with acute ischemic stroke.

Background and aims: Malnutrition is a prevalent problem occurring in different diseases. Hemorrhagic transformation (HT) is a severe complication of acute ischemic stroke (AIS). Few studies have evaluated the association between malnutrition risk and hemorrhagic transformation in patients with acute stroke. We aim to investigate the influence of malnutrition risk on the risk of hemorrhagic transformation in patients with AIS. Methods: A total of 182 consecutive adults with HT and 182 age- and sex-matched patients with stroke were enrolled in this study. The controlling nutritional status (CONUT) score was calculated to evaluate the malnutrition risk. HT was detected by follow-up imaging assessment and was radiologically classified as hemorrhagic infarction type 1 or 2 or parenchymal hematoma type 1 or 2. Logistic regression models were conducted when participants were divided into different malnutrition risk groups according to the objective nutritional score to assess the risk for HT. Results: The prevalence of moderate to severe malnutrition risk in patients with AIS was 12.5%, according to the CONUT score. Univariate analysis showed that the CONUT score is significantly higher in patients with HT than those without HT. After adjusting for potential covariables, the patients with mild risk and moderate to severe malnutrition risk were associated with a higher risk of HT compared to the patients in the normal nutritional status group [odds ratio, 3.180 (95% CI, 1.139-8.874), P = 0.027; odds ratio, 3.960 (95% CI, 1.015-15.453), P = 0.048, respectively]. Conclusion: Malnutrition risk, measured by CONUT score, was significantly associated with an increased risk of hemorrhagic transformation in patients with AIS.

[Distribution of surface components in spray-dried powder of binary system of berberine hydrochloride and dextran based on hydrodynamic size].

The present study explored the correlation between the hydrodynamic size(i.e., hydrated particle size) and the surface component distribution of spray-dried powder based on the binary system model of berberine hydrochloride and dextran. A variety of mixture solutions containing substances of different proportions were prepared, and the hydrated particle sizes of the solutions were measured by laser light scattering technique. Then the effects of molecular weight and mixing proportion on the particle size were analyzed. After the solutions were spray-dried, the surface components of spray-dried powder were determined by X-ray photoelectron spectroscopy. The changes of hydrated particle size of the two substances in different solutions were measured with the altered solution environments, and the distribution of surface components after spray-drying was observed. The results of particle size measurement showed that different solution environments would change the hydrodynamic size of substances. Specifically, the particle size of berberine hydrochloride increased with the increase in ionic strength and solution pH, while the particle size of dextran decreased with the increase in ionic strength and increased with the increase in solution pH. The results of surface components of the spray-dried powder indicated that berberine hydrochloride was prone to accumulate on the surface of particles during spray-drying because of its large hydrodynamic size. Therefore, hydrodynamic size is considered an important factor affecting the surface component distribution of spray-dried powder. As revealed by scanning electron microscopy of the particle morphology of spray-dried powder, the particles of berberine hydrochloride spray-dried powder were irregularly elliptic, and the particles of dextran and mixture spray-dried powders were irregularly spherical with the shrunken surface. Finally, the FT4 powder rheometer and DVS instrument were used to determine the stability, adhesion, and hygroscopicity of the powder. The results showed that when berberine hydrochloride was enriched on the surface, the adhesion of the mixture increased and the fluidity became worse, but the hygroscopicity was improved to a certain extent. In addition, as found by hygroscopic kinetic curve fitting of spray-dried powder, the hygroscopic behaviors of all spray-dried powder conformed to the double exponential function.

Objectification and ambiguity of body image in women with Polycystic Ovary Syndrome: A mixed-method study.

BACKGROUND: The manifestations of Polycystic Ovary Syndrome (PCOS), including acne, hirsutism, obesity, uncertain fertility, etc., can make women anxious, worried, or even depressed with their appearance and body. However, little relevant research has been conducted in the Chinese context. This mixed-method study aimed to understand how women with PCOS in China perceive their bodies and to examine the association between body image and depression. METHODS: First, 101 PCOS patients participated in a survey using the Body Surveillance subscale of the Objectified Body Consciousness Scale, the Short-form Mishel Uncertainty in Illness Scale, the Appearance Anxiety Scale, and the Beck Depression Inventory-II, which measured participants' self-objectification, illness ambiguity, appearance anxiety, and depression, respectively. Second, fifteen women joined face-to-face semi-structured in-depth interviews, investigating their illness ambiguity, objectified experience, and behaviors to pursue beauty. RESULTS: Results indicated a high level of self-objectification, illness ambiguity, appearance anxiety, and depression among women with PCOS in China and supported the significant associations among the outcomes. Qualitative findings presented a body image of the precarious body, indiscernible identity, and distraught mind. LIMITATIONS: A convenient sampling method was used. The generalization of the study results needs further validation. Future longitudinal studies are necessary to clarify the causal relationships among outcomes. CONCLUSIONS: This study presented women's body image with PCOS and found the negative impact of body image on their depression levels. This study was of both theoretical and practical significance. Appropriate mind-body therapies were suggested for them.

Microbiota in health and diseases.

The role of microbiota in health and diseases is being highlighted by numerous studies since its discovery. Depending on the localized regions, microbiota can be classified into gut, oral, respiratory, and skin microbiota. The microbial communities are in symbiosis with the host, contributing to homeostasis and regulating immune function. However, microbiota dysbiosis can lead to dysregulation of bodily functions and diseases including cardiovascular diseases (CVDs), cancers, respiratory diseases, etc. In this review, we discuss the current knowledge of how microbiota links to host health or pathogenesis. We first summarize the research of microbiota in healthy conditions, including the gut-brain axis, colonization resistance and immune modulation. Then, we highlight the pathogenesis of microbiota dysbiosis in disease development and progression, primarily associated with dysregulation of community composition, modulation of host immune response, and induction of chronic inflammation. Finally, we introduce the clinical approaches that utilize microbiota for disease treatment, such as microbiota modulation and fecal microbial transplantation.

Chinese Medicine Formula Siwu-Yin Inhibits Esophageal Precancerous Lesions by Improving Intestinal Flora and Macrophage Polarization.

Siwu-Yin (SWY), a traditional Chinese medicinal formula, can replenish blood and nourish Yin. It was recorded in ancient Chinese medicine books in treating esophageal dysphagia, which has similar symptoms and prognosis with esophageal precancerous lesions and esophageal cancer. However, its effect has not been established in vivo. This study explores the antiesophageal cancer effect of SWY on rats with esophageal precancerous lesions. By performing 16S rRNA gene sequencing and metabolomics, it was suggested that SWY may improve the composition of intestinal flora of rats by regulating the synthesis and secretion of bile acids. In addition, flow cytometry results showed that SWY treatment modified tumor microenvironment by improving macrophage polarization and therefore inhibiting the occurrence of esophageal precancerous lesions.

[Statolith microstructure and growth characteristics of Sthenoeuthis oualaniensis in the northwest Indian Ocean]. / 西北印度洋海域鸢乌贼耳石微结构及生长特性.

Statolith is one of the most important hard tissues to study the age, growth, population structure and life history of cephalopods. In order to stuty statolith microstructure and growth characteristics of Sthenoeuthis oualaniensis in the northwest Indian Ocean, 1009 samples were collected by Chinese light falling-net fishery fleets during investigation and production in the northwest Indian Ocean from February to May of 2019. Total statolith length (TSL), lateral dome length (LDL), wing length (WL) and maximum width (MW) were taken as the indicators of morphological feature of the statolith, combined with the age data, the statolith microstructure and growth characteristics of S. oualaniensis were studied. The results showed that the statolith microstructure could be divided into postnuclear zone, dark zone and peripheral zone according to the width of growth increment. The analysis of covariance showed that there was no growth difference of TSL, LDL, WL and MW between different sexes. The relationships between TSL, WL, MW and age were best described by the power functions, while the relationship between LDL and age was best described by the linear function. In general, with the increase of age, the instantaneous relative growth rate and absolute growth rate of TSL, WL, LDL and MW decreased, and 140-180 d may be the age of sexual maturity for this squid.

[Factors influencing beak morphology of Sthenoteuthis oualaniensis in the northwest Indian Ocean.] / è¥¿åŒ—å°åº¦æ´‹é¸¢ä¹Œè´¼è§’è´¨é¢šå¤–å½¢å˜åŒ–çš„å½±å“å› ç´ .

With 1009 Sthenoteuthis oualaniensis samples collected by Chinese light falling-net fishery during February to May in the northwest Indian Ocean, we analyzed the influencing factors of the morphology change of the beak. There were significant differences in the morphologic growth between genders, different gonad maturity stages, and different mantle length. The increment of characteristic parameters growth peaked in the mantle length between 201 and 250 mm, and in the Ⅱ and Ⅲ stages of gonad maturity for females and males, respectively. There was no significant difference in the ratio of morphometric parameters to crest length (CL) between the genders, diffe-rent gonad maturity stages, and different mantle length, except for the ratio of upper hood length to upper crest length (UWL/UCL) and lower hood length to lower crest length (LHL/LCL). The ratio of each characteristic parameter to CL was nearly stable with the change of sex, gonad maturity and mantle length, suggesting consistent growth of each dome of beak. Our results suggested the mantle length of 201 mm to 250 mm seemed to be the threshold for the morphologic growth of beak on the body size, while the gonad maturity of Ⅱ and Ⅲ stages seemed to be the threshold for the morphologic growth of beak on the gonad maturity.

Overexpression of ABCC1 Confers Drug Resistance to Betulin.

Betulin is a lupane-type pentacyclic triterpene, which is isolated from birch bark. It has a broad spectrum of biological and pharmacological properties, such as anti-inflammatory, anti-tumor, anti-viral, and anti-bacterial activity. Herein, we explored the factors that may result in betulin resistance, especially with respect to its interaction with ATP-binding cassette subfamily C member 1 (ABCC1). ABCC1 is an important member of the ATP-binding cassette (ABC) transporter family, which is central to mediating multidrug resistance (MDR) in naturally derived anticancer agents. An MTT-based cell viability assay showed that ABCC1 overexpression has the ability to desensitize both cancer cell line and gene-transfected cell line to betulin and that this betulin-induced resistance can be antagonized by a known ABCC1 inhibitor MK571 at 25 µM. Additionally, betulin upregulates the ABCC1 protein expression level in both concentration-dependent and time-dependent manners, also blocks the transport function mediated by ABCC1. Subsequently, a high affinity score of betulin was achieved in a computational docking analysis, demonstrating a strong interaction of betulin with ABCC1.

Natural Product as Substrates of ABC Transporters: A Review.

BACKGROUND: To date, many compounds extracted from natural products have anti-tumor activity, such as citronellol, ellagitannin-containing pomegranate extract, etc. Evidence from clinical context shows that multidrug resistance is an obstacle that impedes the effectiveness of natural products, such as chemotherapeutic agents, paclitaxel and vincristine. Overexpression of ATP- Binding Cassette (ABC) transporters is the leading cause of MDR. Therefore, it is crucial to investigate whether these natural products are substrates of MDR-associated ABC transporters, which may benefit the development of their clinical usage. OBJECTIVE: This review summarizes the latest insight on natural products possessing substrate profile and analyzes some possible directions for future drug discovery. CONCLUSION: The anti-tumor effects of natural products are constantly being explored, but the drug resistance issues cannot be ignored, which limits their prospects as anti-tumor drugs to a certain extent. At the same time, some natural products are taken as a daily diet, and their possible role in increasing the drug resistance of the substrate should arouse the attention of clinical cancer patients.

NVP-CGM097, an HDM2 Inhibitor, Antagonizes ATP-Binding Cassette Subfamily B Member 1-Mediated Drug Resistance.

Multidrug resistance (MDR) is a major challenge in the treatment of tumors. It refers to cancer cells become resistant to not only the therapeutic drug, but also cross-resistant to multiple drugs with distinct structures and mechanisms of action when they are exposed to a drug for a period of time. An essential mechanism of MDR is the aberrant expression and function of ATP-binding cassette (ABC) transporters. Therefore, blocking the function of ABC transporters has the therapeutic potential in reversing MDR. The hdm2 oncogene product, HDM2 (also known as MDM2), is an important negative regulator of the p53 tumor suppressor. NVP-CGM097 is an HDM2 inhibitor that can inhibit the proliferation of tumor cells and is currently under clinical trials. In this study, we evaluate whether NVP-CGM097 could reverse ABCB1-mediated MDR. The results of reversal experiment showed that NVP-CGM097 remarkably reversed ABCB1-mediated MDR but not ABCG2-mediated MDR. The results of Western blot and immunofluorescence suggested that the level of expression and subcellular localization of ABCB1 protein were not significantly altered by NVP-CGM097. Mechanism studies indicated that NVP-CGM097 could reverse ABCB1-mediated MDR by directly blocking the ABCB1-mediated drug efflux and raising the accumulation of chemotherapeutic drugs in cancer cells. ATPase analysis showed that low concentration NVP-CGM097 activates ABCB1 ATPase activity while high concentration NVP-CGM097 inhibited ABCB1-associated ATPase. Docking study indicated that NVP-CGM097 tended to bind to the inhibitory site, which led to slight but critical conformational changes in the transporter and reduced the ATPase activity. Overall, our study demonstrates that NVP-CGM097 can be used in conjunction with chemotherapeutic drugs to counteract MDR and improve the antitumor responses.

Erdafitinib Antagonizes ABCB1-Mediated Multidrug Resistance in Cancer Cells.

ABCB1 overexpression is known to contribute to multidrug resistance (MDR) in cancers. Therefore, it is critical to find effective drugs to target ABCB1 and overcome MDR. Erdafitinib is a tyrosine kinase inhibitor (TKI) of fibroblast growth factor receptor (FGFR) that is approved by the FDA to treat urothelial carcinoma. Previous studies have demonstrated that some TKIs exhibit MDR reversal effect. In this work, we examined whether erdafitinib could reverse MDR mediated by ABCB1. The results of reversal experiments showed that erdafitinib remarkably reversed ABCB1-mediated MDR without affecting ABCG2-mediated MDR. The results of immunofluorescence and Western blot analysis demonstrated that erdafitinib did not affect the expression of ABCB1 or its cellular localization. Further study revealed that erdafitinib inhibited ABCB1 efflux function leading to increasing intracellular drug accumulation, thereby reversing MDR. Furthermore, ATPase assay indicated that erdafitinib activated the ABCB1 ATPase activity. Docking study suggested that erdafitinib interacted with ABCB1 on the drug-binding sites. In summary, this study demonstrated that erdafitinib can reverse MDR mediated by ABCB1, suggesting that combination of erdafitinib and ABCB1-substrate conventional chemotherapeutic drugs could potentially be used to overcome MDR mediated by ABCB1.