FRAX486, a PAK inhibitor, overcomes ABCB1-mediated multidrug resistance in breast cancer cells.

The overexpression of P-glycoprotein (P-gp/ABCB1) is a leading cause of multidrug resistance (MDR). Hence, it is crucial to discover effective pharmaceuticals that counteract ABCB1-mediated multidrug resistance. FRAX486 is a p21-activated kinase (PAK) inhibitor. The objective of this study was to investigate whether FRAX486 can reverse ABCB1-mediated multidrug resistance, while also exploring its mechanism of action. The CCK8 assay demonstrated that FRAX486 significantly reversed ABCB1-mediated multidrug resistance. Furthermore, western blotting and immunofluorescence experiments revealed that FRAX486 had no impact on expression level and intracellular localization of ABCB1. Notably, FRAX486 was found to enhance intracellular drug accumulation and reduce efflux, resulting in the reversal of multidrug resistance. Docking analysis also indicated a strong affinity between FRAX486 and ABCB1. This study highlights the ability of FRAX486 to reverse ABCB1-mediated multidrug resistance and provides valuable insights for its clinical application.

Development and Testing of Species-Specific Primers for Detecting the Presence of the Northern Pacific Sea Star (Asterias amurensis) from Environmental DNA.

The starfish Asterias amurensis, a well-known predator of molluscan species in intertidal ecosystems, has caused substantial ecological and economic losses in North China such as offshore Qingdao. Effective monitoring and prevention measures are urged to minimize its negative impacts. Compared with traditional biomonitoring methods, environmental DNA technology has emerged as a powerful and cost-efficient tool for inferring species' presence and abundance. In this study, we developed a pair of species-specific primers (i.e., Ast-F and Ast-R) for the A. amurensis mitochondrial COI gene and tested its utility in amplifying and quantifying the DNA fragments from environmental samples under both laboratory and field conditions. The results of controlled water tank experiments demonstrated that the amount of eDNA released by A. amurensis was positively related to its biomass; after the removal of the starfish, the eDNA degraded significantly in 24 h and remained detectable for 8 days. The number of eDNA copies enriched tended to increase with smaller pore size of filter membrane and larger volume of filtered water. For field tests, we confirmed the validation of our approach in six locations in Qingdao by filtering 1000 ml water per sample with a 0.45-µm pore size filtration. All the amplification products generated a single and bright band via gel electrophoresis, and the quantitative PCR results unveiled significant differences in eDNA copies. This study provided an eDNA-based approach for investigating the distribution and biomass of A. amurensis, which may help to formulate early warning and management strategies in coastal Qingdao and other regions.

FRAX486, a PAK inhibitor, overcomes ABCB1-mediated multidrug resistance in breast cancer cells

The overexpression of P-glycoprotein (P-gp/ABCB1) is a leading cause of multidrug resistance (MDR). Hence, it is crucial to discover effective pharmaceuticals that counteract ABCB1-mediated multidrug resistance. FRAX486 is a p21-activated kinase (PAK) inhibitor. The objective of this study was to investigate whether FRAX486 can reverse ABCB1-mediated multidrug resistance, while also exploring its mechanism of action. The CCK8 assay demonstrated that FRAX486 significantly reversed ABCB1-mediated multidrug resistance. Furthermore, western blotting and immunofluorescence experiments revealed that FRAX486 had no impact on expression level and intracellular localization of ABCB1. Notably, FRAX486 was found to enhance intracellular drug accumulation and reduce efflux, resulting in the reversal of multidrug resistance. Docking analysis also indicated a strong affinity between FRAX486 and ABCB1. This study highlights the ability of FRAX486 to reverse ABCB1-mediated multidrug resistance and provides valuable insights for its clinical application.

5D-QSAR studies of 1H-pyrazole derivatives as EGFR inhibitors.

Epidermal growth factor receptor (EGFR) is highlighted as a target for anticancer treatment. Several EGFR inhibitors were approved in cancer treatment. Comparatively, 5D-QSAR is a new methodology which considers an ensemble of different induced-fit models. Based on 1H-pyrazole derivatives as EGFR inhibitors, a 5D-QSAR was studied in which the method of quasi-atomistic receptor surface modeling was used. The presented QSAR model showed contributions of the hydrogen bond acceptor, and hydrophobic and salt bridge fields to the activity. The QSAR model was statistically validated and also externally validated applying 19 compounds (test set) which were not included in the model generation process. The scramble tests were performed to further verify the robustness. Apart from exploration of the binding of 1H-pyrazole derivatives to the EGFR, the 5D-QSAR model can be helpful to design of new EGFR inhibitors. The five-dimensional quantitative structure-activity relationship (5D-QSAR) of 1H-pyrazole derivatives as EGFR inhibitors with quasi-atomistic receptor surface modeling approach is described.

Prevalence of breast fibroadenoma in healthy physical examination population in Guangdong province of China: a cross-sectional study.

OBJECTIVE: To provide an accurate assessment of the prevalence of breast fibroadenoma in a large population and to confirm the diagnostic accuracy of ultrasound for fibroadenoma. DESIGN: This was a cross-sectional survey. SETTING: This research was conducted at Nanfang Hospital, Guangzhou, Guangdong, China. PARTICIPANTS: A total of 11 898 women aged 18-40 years who underwent breast screening between 1 January 2019 and 31 December 2019 were included in the fibroadenoma prevalence study. From 1 June 2019 to 31 December 2019, 342 breast lesions with pathology reports and preoperative ultrasound images were collected for diagnostic fibroadenoma testing (vs histological diagnostic testing). PRIMARY OUTCOME MEASURES: Pearson's χ2 test was performed to compare the prevalence of different lesions between age groups, and descriptive statistics were used to report the clinical characteristics of fibroadenoma. For ultrasound diagnosis, fibroadenoma was defined as a well-circumscribed lesion with round or oval shape, consisting of a homogeneously hypoechoic or isoechoic solid mass, located parallel to the chest wall with a smooth margin and no posterior shadowing. Diagnostic test results for breast fibroadenoma were stratified by diagnostic type (histological vs ultrasound). RESULTS: Of the women aged 18-40 years, 27.6% (3285/11 898) had an ultrasound diagnosis offibroadenoma. Of these, the prevalence of fibroadenoma was stable across age groups (p=0.14) and did not differ between the left and right sides of the breast. Almost two-thirds of women presented with a single fibroadenoma, and most fibroadenomas did not exceed 1 cm in size. The sensitivity and specificity for fibroadenoma were 97.0% (95% CI for sensitivity: 93.7% to 98.8%) and 91.4% (95% CI for specificity: 85.4% to 95.5%) for ultrasonography, respectively. CONCLUSIONS: The prevalence of fibroadenoma in South China is as high as 27.6%, and ultrasound could be used as a tool to diagnose fibroadenoma.

Cardiovascular risk factors and breast cancer incidence in a large middle-aged cohort study.

BACKGROUND: Several studies have demonstrated that cardiovascular risk factors play a role in the etiology of breast cancer. However, the combined effect of cardiovascular risk factors on the risk of breast cancer is still uncertain. METHODS: Data from the Atherosclerosis Risk in Communities (ARIC) study, a prospective cohort of middle-aged women, were used to investigate the association of individual and combined cardiovascular risk factors with breast cancer. Cox proportional hazards models were applied to calculate the hazard ratio (HR) and 95% confidence intervals (CI). RESULTS: A total of 7501 women were included. During a mean follow-up of 19.7 years, 576 women were diagnosed with breast cancer. White women and premenopausal status were independently associated with increased risk of breast cancer. Of the individual cardiovascular risk factors, only obesity was independently associated with an increased risk of breast cancer (HR 1.29, 95% CI 1.04-1.61). Compared with women without cardiovascular risk factors, women having three or greater, but not those with fewer than three cardiovascular risk factors, had a significantly higher risk of developing breast cancer (HR 1.27, 95% CI 1.06-1.53). Subgroup analyses indicated that women with three or greater cardiovascular risk factors had higher risk of breast cancer among postmenopausal Black women, but not among premenopausal Black and White women. CONCLUSIONS: Combinations of cardiovascular risk factors are associated with increased risk of breast cancer in middle-aged women, especially in postmenopausal Black women. Joint interventions to modify cardiovascular risk factors could be used to prevent breast cancer in these higher-risk individuals.

MAPK4 silencing together with a PARP1 inhibitor as a combination therapy in triple­negative breast cancer cells.

Triple­negative breast cancer (TNBC) is the most common type of cancer among females worldwide and is associated with poor prognosis. Poly ADP­ribose polymerase­1 (PARP1) inhibitors are effective against TNBC with mutations in the breast cancer type 1 susceptibility protein (BRCA1) and/or BRCA2 genes; however, the development of resistance to PARP1 inhibitors limits their use. Thus, identifying strategies to overcome this resistance is urgently required. The aim of the present study was to investigate the potential function and mechanism of small interfering (si)RNA­MAPK4 (siMAPK4) in enhancing the efficacy of a PARP1 inhibitor and reducing the resistance. In the present study, data on the mRNA expression level of MAPK4 in normal breast tissues and TNBC tissues were obtained from The Cancer Genome Atlas database. The mRNA and protein expression levels of MAPK4 in normal breast cells and TNBC cells were analyzed using reverse transcription­quantitative PCR and western blotting, respectively. The phosphorylated (p) histone H2AX (γH2AX) protein expression was assessed via immunofluorescence. Cell Counting Kit­8, wound healing and TUNEL assays were used to determine the proliferative, migratory and apoptotic abilities of HCC1937 cells. MAPK4 was highly expressed in TNBC patient tissues and cell lines. Moreover, overexpression of MAPK4 could promote HCC1937 cell proliferation. Treatment of HCC1937 cells with the combination of siMAPK4 and a PARP1 inhibitor olaparib decreased their proliferation and migration and increased their apoptosis. The protein expression levels of the DNA repair­related proteins p­DNA­dependent protein kinase catalytic subunit (DNA­PK) and RAD51 recombinase (RAD51) were inhibited in the siMAPK4 and siMAPK4 + olaparib groups. However, the marker of a double­stranded break γH2AX showed increased protein expression in the siMAPK4 + olaparib group. As MAPK4 could phosphorylate AKT at threonine 308 (AKTT308), the current study restored p­AKTT308 using a constitutively active AKT plasmid (AKT­CA). p­DNA­PK and RAD51 showed high expression and γH2AX exhibited lower protein expression in the AKT­CA group. The present findings suggested that siMAPK4 can enhance the sensitivity of TNBC cells to PARP1 inhibitors.

Methylated biomarkers for breast cancer identified through public database analysis and plasma target capture sequencing.

BACKGROUND: Aberrant methylation is common during the early stage of cancer development. This study was designed to investigate DNA methylation as biomarker for breast cancer. METHODS: Public database analysis and methylation-specific whole-gene sequencing were conducted to identify methylated biomarkers that would enable early non-invasive diagnosis of breast cancer. Firstly, the data was obtained from the TCGA Database and the Blueprint Epigenome Database. Secondly, methylation-specific whole-gene sequencing was conducted in 10 female patients with early-stage breast cancer and 10 healthy female volunteers from Nanfang Hospital of Southern Medical University between March 2018 and July 2018. Thirdly, the R language was used for data analysis, and KEGG and DAVID online tool was used for annotations. RESULTS: We found that methylation levels at 13 cytosine-phosphate-guanine (CpG) sites (cg04066177, cg04281344, cg05995576, cg06221609, cg08642731, cg11388802, cg12665414, cg14557216, cg19404723, cg19457909, cg24570211, cg25818763, and cg26215982) in the malignant tissue DNA were highly comparable to those of circulating cell-free DNA (cfDNA) of breast cancer patients, but were significantly different from those of normal tissue DNA, cfDNA of healthy women, and leukocyte DNA. In addition, three CpG sites (cg04281344, cg24570211, and cg26215982) were confirmed in clinical research, which showed that the sensitivity and specificity of these CpGs as biomarkers for breast cancer were 69.4-83.7% and 85.7-88.6%, respectively. CONCLUSIONS: New biomarkers were identified and confirmed for breast cancer by comparing the methylation of tumour tissues, leukocytes, and non-plasma DNA.

The miR-1185-2-3p-GOLPH3L pathway promotes glucose metabolism in breast cancer by stabilizing p53-induced SERPINE1.

BACKGROUND: Phosphatidylinositol-4-phosphate-binding protein GOLPH3L is overexpressed in human ductal carcinoma of the breast, and its expression levels correlate with the prognosis of breast cancer patients. However, the roles of GOLPH3L in breast tumorigenesis remain unclear. METHODS: We assessed the expression and biological function of GOLPH3L in breast cancer by combining bioinformatic prediction, metabolomics analysis and RNA-seq to determine the GOLPH3L-related pathways involved in tumorigenesis. Dual-luciferase reporter assay and coimmunoprecipitation (Co-IP) were used to explore the expression regulation mechanism of GOLPH3L. RESULTS: We demonstrated that knockdown of GOLPH3L in human breast cancer cells significantly suppressed their proliferation, survival, and migration and suppressed tumor growth in vivo, while overexpression of GOLPH3L promoted aggressive tumorigenic activities. We found that miRNA-1185-2-3p, the expression of which is decreased in human breast cancers and is inversely correlated with the prognosis of breast cancer patients, is directly involved in suppressing the expression of GOLPH3L. Metabolomics microarray analysis and transcriptome sequencing analysis revealed that GOLPH3L promotes central carbon metabolism in breast cancer by stabilizing the p53 suppressor SERPINE1. CONCLUSIONS: In summary, we discovered a miRNA-GOLPH3L-SERPINE1 pathway that plays important roles in the metabolism of breast cancer and provides new therapeutic targets for human breast cancer.

miR-409-3p sensitizes colon cancer cells to oxaliplatin by inhibiting Beclin-1-mediated autophagy.

The chemoresistance of colon cancer cells limits the efficacy of chemotherapy. miR-409-3p has been shown to be downregulated in various types of cancer. In the present study, we examined the role of miR-409-3p in colon cancer as well as the effects of miR­409-3p on the sensitivity of colon cancer cells to oxaliplatin. The expression of miR-409 was significantly downregulated in the human colon cancer cell lines compared with the normal colon epithelial cells. Importantly, the miR-409-3p expression levels were lower in human colon cancer patient samples than in normal colon tissues. Moreover, we observed a negative correlation between the miR­409-3p levels and resistance to oxaliplatin: the oxaliplatin-resistant colon cancer cells exhibited significantly downregulated miR­409-3p levels, but higher autophagic activity than the oxaliplatin-sensitive cells. Using bioinformatics analysis, we predicted that miR­409-3p miRNA binds to the key autophagy gene encoding Beclin-1. Our findings indicated that the overexpression of miR­409-3p inhibited Beclin-1 expression and autophagic activity by binding to the 3'-untranslated region of Beclin-1 mRNA. In addition, the overexpression of miR­409-3p enhanced the chemosensitivity of the oxaliplatin-sensitive and oxaliplatin-resistant colon cancer cells. The restoration of Beclin-1 abrogated these effects of miR­409-3p. In a xenograft model using nude mice, we examined the effects of miR­409-3p on tumor growth during chemotherapy. miR­409-3p overexpression sensitized the tumor to chemotherapy, while inhibiting chemotherapy-induced autophagy in a manner dependent on Beclin-1. The findings of our study suggest that miR-409-3p is capable of enhancing the chemosensitivity of colon cancer cells by inhibiting Beclin-1-mediated autophagy.

Long noncoding RNA aberrant expression profiles after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy of AGC ascertained by microarray analysis.

Long noncoding RNAs (lncRNAs) have been shown to be involved in the development and progression of advanced gastric cancer (AGC). However, the roles of lncRNAs in advanced gastric cancer during the process of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are not well understood. A high-throughput microarray analysis was performed to compare the expression profiles of lncRNAs and messenger RNAs (mRNAs) in AGC serum samples during the process of CRS + HIPEC. Several potentially AGC-associated lncRNAs were verified by real-time quantitative reverse transcription polymerase chain reaction (PCR) analysis. Using abundant and varied probes, we were able to assess 33,045 lncRNAs and 30,215 mRNAs in our microarray. We found that 566 lncRNAs were differentially expressed (2-fold change) in AGC serum samples, indicating the significantly up- or downregulated lncRNAs play important roles in AGC during the process of CRS + HIPEC. Quantitative PCR results further verified that eight lncRNAs were aberrantly expressed in AGC serum samples after CRS + HIEC compared with matched serum sample before CRS + HIPEC. Among them, BC031243 and RP11-356I2.2 were the most aberrantly expressed lncRNAs, as estimated by quantitative PCR in six pairs of AGC serum samples. Our study demonstrated the expression patterns of lncRNAs in AGC serums before and after CRS + HIPEC by microarray. These results revealed that lncRNAs were differentially expressed during the process of CRS + HIPEC, suggesting that they might play key roles in tumor development.