Correlation between rs13347 polymorphism of CD44 gene and the risk of occurring breast cancer: A protocol for systematic review and meta-analysis

BACKGROUND

With the attention paid to the heritability of breast cancer, the search for the genetic susceptibility gene of breast cancer has become a hot spot. At present, a number of studies have explored the relationship between rs13347 polymorphism of cluster of differentiation 44 (CD44) gene and breast cancer, but the research conclusions are inconsistent. Therefore, we will use this meta-analysis to explore the role of this gene polymorphism in breast cancer susceptibility.

METHODS

The search time is set from the establishment of the database in March 2021 in this study. The search database include China National Knowledge Infrastructure, Wanfang, VIP Information Chinese Journal Service Platform, and China Biology Medicine disc, PubMed, EMBASE, Web of Science and the Cochrane Library. The subjects are observational studies on the relationship between rs13347 polymorphism of CD44 gene and breast cancer (including case-control study, cross-sectional study and a cohort study). The language is limited to English and Chinese. The data of the included study are extracted and the literature quality is evaluated by two researchers independently. The data are statistically analyzed by Stata 16.0 software.

RESULTS

Based on the existing studies, this study will systematically evaluate the relationship between CD44 gene rs13347 polymorphism and breast cancer.

CONCLUSION

This study will provide evidence-based medical evidence to clarify the role of CD44 gene polymorphism in breast cancer, and provide help for the early detection and preventive intervention of breast cancer.

ETHICS AND DISSEMINATION

Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval will not be required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/WBC7F.

Androgen Receptor Regulates CD44 Expression in Bladder Cancer

The androgen receptor (AR) is important in the development of both experimental and human bladder cancer. However, the role of AR in bladder cancer growth and progression is less clear, with literature indicating that more advanced stage and grade disease are associated with reduced AR expression. To determine the mechanisms underlying these relationships, we profiled AR-expressing human bladder cancer cells by AR chromatin immunoprecipitation sequencing and complementary transcriptomic approaches in response to in vitro stimulation by the synthetic androgen R1881. In vivo functional genomics consisting of pooled shRNA or pooled open reading frame libraries was employed to evaluate 97 genes that recapitulate the direction of expression associated with androgen stimulation. Interestingly, we identified CD44, the receptor for hyaluronic acid, a potent biomarker and driver of progressive disease in multiple tumor types, as significantly associated with androgen stimulation. CRISPR-based mutagenesis of androgen response elements associated with CD44 identified a novel silencer element leading to the direct transcriptional repression of CD44 expression. In human patients with bladder cancer, tumor AR and CD44 mRNA and protein expression were inversely correlated, suggesting a clinically relevant AR-CD44 axis. Collectively, our work describes a novel mechanism partly explaining the inverse relationship between AR and bladder cancer tumor progression and suggests that AR and CD44 expression may be useful for prognostication and therapeutic selection in primary bladder cancer. SIGNIFICANCE: This study describes novel AREs that suppress CD44 and an expected inverse correlation of AR-CD44 expression observed in human bladder tumors.

Single-Cell Transcriptome Analysis Uncovers Intratumoral Heterogeneity and Underlying Mechanisms for Drug Resistance in Hepatobiliary Tumor Organoids

Molecular heterogeneity of hepatobiliary tumor including intertumoral and intratumoral disparity always leads to drug resistance. Here, seven hepatobiliary tumor organoids are generated to explore heterogeneity and evolution via single-cell RNA sequencing. HCC272 with high status of epithelia-mesenchymal transition proves broad-spectrum drug resistance. By examining the expression pattern of cancer stem cells markers (e.g., PROM1, CD44, and EPCAM), it is found that CD44 positive population may render drug resistance in HCC272. UMAP and pseudo-time analysis identify the intratumoral heterogeneity and distinct evolutionary trajectories, of which catenin beta-1 (CTNNB1), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and nuclear paraspeckle assembly transcript 1 (NEAT1) advantage expression clusters are commonly shared across hepatobiliary organoids. CellphoneDB analysis further implies that metabolism advantage organoids with enrichment of hypoxia signal upregulate NEAT1 expression in CD44 subgroup and mediate drug resistance that relies on Jak-STAT pathway. Moreover, metabolism advantage clusters shared in several organoids have similar characteristic genes (GAPDH, NDRG1 (N-Myc downstream regulated 1), ALDOA, and CA9). The combination of GAPDH and NDRG1 is an independent risk factor and predictor for patient survival. This study delineates heterogeneity of hepatobiliary tumor organoids and proposes that the collaboration of intratumoral heterogenic subpopulations renders malignant phenotypes and drug resistance.

Tachypacing-induced CREB/CD44 signaling contributes to the suppression of L-type calcium channel expression and the development of atrial remodeling

BACKGROUND

Atrial fibrillation (AF), a common arrhythmia in clinics, is characterized as downregulation of L-type calcium channel (LTCC) and shortening of atrial action potential duration (APD). Our prior studies have shown the association of CD44 with AF genesis.

OBJECTIVE

The purpose of this study was to explore the potential role of CD44 and its related signaling in tachypacing-induced downregulation of LTCC.

METHODS AND RESULTS

In vitro, tachypacing in atrium-derived myocytes (HL-1 cell line) induced activation (phosphorylation) of cyclic adenosine monophosphate response element-binding protein (CREB). Furthermore, tachypacing promoted an association between CREB and CD44 in HL-1 myocytes, which was documented in atrial tissues from patients with AF. Deletion and mutational analysis of the LTCC promoter along with chromatin immunoprecipitation revealed that cyclic adenosine monophosphate response element is essential for tachypacing-inhibited LTCC transcription. Tachypacing also hindered the binding of p-CREB to the promoter of LTCC. Blockade of CREB/CD44 signaling in HL-1 cells attenuated tachypacing-triggered downregulation of LTCC and shortening of APD. Atrial myocytes isolated from CD44^-/- mice exhibited higher LTCC current and longer APD than did those from wild-type mice. Ex vivo, tachypacing caused less activation of CREB in CD44^-/- mice than in wild-type mice. In vivo, burst atrial pacing stimulated less inducibility of AF in CREB inhibitor-treated mice than in controls.

CONCLUSION

Tachypacing-induced CREB/CD44 signaling contributes to the suppression of LTCC, which provides valuable information about the pathogenesis of atrial modeling and AF.

Graphene quantum dot formulation for cancer imaging and redox-based drug delivery

This work develops a new multifunctional biocompatible anticancer nanoformulation to provide targeted image-guided cancer-selective therapeutics. It consists of three active covalently bound components: (1) biocompatible nitrogen-doped graphene quantum dots (GQDs) as a multifunctional delivery and imaging platform, (2) hyaluronic acid (HA) unit targeted to the CD44 receptors on a variety of cancer cells, and (3) oxidative stress-based cancer-selective ferrocene (Fc) therapeutic. The biocompatible GQD platform synthesized from glucosamine exhibits high-yield intrinsic fluorescence. It is utilized for tracking Fc-GQD-HA formulation in vitro indicating internalization enhancement in HeLa cells targeted by the HA over non-cancer HEK-293 cells not overexpressing CD44 receptor. Fc-GQD-HA, non-toxic at 1 mg/mL to HEK-293 cells, induces cytotoxic response in HeLa enhanced over time, while therapeutic ROS generation by Fc-GQD-HA is ~3 times greater than that of Fc alone. This outlines the targeted delivery, imaging, and cancer-specific treatment capabilities of the new Fc-GQD-HA formulation enabling desired cancer-focused nanotherapeutic approach.

Increased CD44 Expression and MEK Activity Predict Worse Prognosis in Gastric Adenocarcinoma Patients Undergoing Gastrectomy

PURPOSE

We have shown that activation of the receptor tyrosine kinase (RTK)-RAS pathway in gastric adenocarcinoma (GA) promotes acquisition of cancer stem-like cell (CSC) phenotypes including metastasis and chemotherapy resistance. Here, we evaluated the prognostic value of the CSC marker CD44 and the RTK-RAS activation marker phosphorylated MEK (p-MEK) in patients with resectable GA.

METHODS

CD44 and p-MEK were measured in tumors from GA patients who underwent curative-intent gastrectomy at Fujian Medical University Union Hospital (FMUUH, n = 134) and Memorial Sloan Kettering Cancer Center (MSKCC, n = 56). Overall survival (OS) was estimated by the Kaplan-Meier method, and multivariate analysis was performed by Cox proportional hazards regression modeling.

RESULTS

Despite multiple significant differences in clinicopathologic characteristics between the FMUUH and MSKCC cohorts, high CD44 and high p-MEK expression were both independent negative prognostic factors for OS on univariate analysis in both cohorts (p < 0.05). Both factors were also significant on multivariate analysis when the cohorts were combined (p ≤ 0.003). On subgroup analysis, the 5-year OS of patients with both high CD44 and high p-MEK was 39.5-41.6% compared with 55.4-66.4% for patients with low CD44. High CD44 expression was associated with more advanced TNM stage in the FMUUH cohort and larger tumor size and undifferentiated histology in the MSKCC cohort. High p-MEK was associated with undifferentiated histology in the FMUUH cohort and larger tumor size in the MSKCC cohort.

CONCLUSIONS

Increased CD44 and p-MEK expression are predictive of worse OS in GA patients. Thus, targeting the RTK-RAS pathway may benefit patients with CD44-positive, RAS-activated GA by inhibiting metastasis and reversing chemotherapy resistance.

MicroRNA-138 suppresses glioblastoma proliferation through downregulation of CD44

Tumor suppressive microRNAs (miRNAs) are increasingly implicated in the development of anti-tumor therapy by reprogramming gene network that are aberrantly regulated in cancer cells. This study aimed to determine the therapeutic potential of putative tumor suppressive miRNA, miR-138, against glioblastoma (GBM). Whole transcriptome and miRNA expression profiling analyses on human GBM patient tissues identified miR-138 as one of the significantly downregulated miRNAs with an inverse correlation with CD44 expression. Transient overexpression of miR-138 in GBM cells inhibited cell proliferation, cell cycle, migration, and wound healing capability. We unveiled that miR-138 negatively regulates the expression of CD44 by directly binding to the 3' UTR of CD44. CD44 inhibition by miR-138 resulted in an inhibition of glioblastoma cell proliferation in vitro through cell cycle arrest as evidenced by a significant induction of p27 and its translocation into nucleus. Ectopic expression of miR-138 also increased survival rates in mice that had an intracranial xenograft tumor derived from human patient-derived primary GBM cells. In conclusion, we demonstrated a therapeutic potential of tumor suppressive miR-138 through direct downregulation of CD44 for the treatment of primary GBM.

Wnt/β-catenin Signaling Inhibitors suppress the Tumor-initiating properties of a CD44+CD133+ subpopulation of Caco-2 cells

Tumor-initiating cells or cancer stem cells are a subset of cancer cells that have tumorigenic potential in human cancer. Although several markers have been proposed to distinguish tumor-initiating cells from colorectal cancer cells, little is known about how this subpopulation contributes to tumorigenesis. Here, we characterized a tumor-initiating cell subpopulation from Caco-2 colorectal cancer cells. Based on the findings that Caco-2 cell subpopulations express different cell surface markers, we were able to discriminate three main fractions, CD44-CD133-, CD44-CD133+, and CD44+CD133+ subsets, and characterized their biochemical and tumorigenic properties. Our results show that CD44+CD133+ cells possessed an unusual capacity to proliferate and could form tumors when transplanted into NSG mice. Additionally, primary tumors grown from CD44+CD133+ Caco-2 cells contained mixed populations of CD44+CD133+ and non-CD44+CD133+ Caco-2 cells, indicating that the full phenotypic heterogeneity of the parental Caco-2 cells was re-created. Notably, only the CD44+CD133+ subset of Caco-2-derived primary tumors had tumorigenic potential in NSG mice, and the tumor growth of CD44+CD133+ cells was faster in secondary xenografts than in primary transplants. Gene expression analysis revealed that the Wnt/β-catenin pathway was over-activated in CD44+CD133+ cells, and the growth and tumorigenic potential of this subpopulation were significantly suppressed by small-molecule Wnt/β-catenin signaling inhibitors. Our findings suggest that the CD44+CD133+ subpopulation from Caco-2 cells was highly enriched in tumorigenic cells and will be useful for investigating the mechanisms leading to human colorectal cancer development.

Targeting the Stromal Pro-Tumoral Hyaluronan-CD44 Pathway in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies. Present-day treatments have not shown real improvements in reducing the high mortality rate and the short survival of the disease. The average survival is less than 5% after 5 years. New innovative treatments are necessary to curtail the situation. The very dense pancreatic cancer stroma is a barrier that impedes the access of chemotherapeutic drugs and at the same time establishes a pro-proliferative symbiosis with the tumor, thus targeting the stroma has been suggested by many authors. No ideal drug or drug combination for this targeting has been found as yet. With this goal in mind, here we have explored a different complementary treatment based on abundant previous publications on repurposed drugs. The cell surface protein CD44 is the main receptor for hyaluronan binding. Many malignant tumors show over-expression/over-activity of both. This is particularly significant in pancreatic cancer. The independent inhibition of hyaluronan-producing cells, hyaluronan synthesis, and/or CD44 expression, has been found to decrease the tumor cell's proliferation, motility, invasion, and metastatic abilities. Targeting the hyaluronan-CD44 pathway seems to have been bypassed by conventional mainstream oncological practice. There are existing drugs that decrease the activity/expression of hyaluronan and CD44: 4-methylumbelliferone and bromelain respectively. Some drugs inhibit hyaluronan-producing cells such as pirfenidone. The association of these three drugs has never been tested either in the laboratory or in the clinical setting. We present a hypothesis, sustained by hard experimental evidence, suggesting that the simultaneous use of these nontoxic drugs can achieve synergistic or added effects in reducing invasion and metastatic potential, in PDAC. A non-toxic, low-cost scheme for inhibiting this pathway may offer an additional weapon for treating pancreatic cancer.

Lack of association of CD44-rs353630 and CHI3L2-rs684559 with pancreatic ductal adenocarcinoma survival

Although pancreatic ductal adenocarcinoma (PDAC) survival is poor, there are differences in patients' response to the treatments. Detection of predictive biomarkers explaining these differences is of the utmost importance. In a recent study two genetic markers (CD44-rs353630 and CHI3L2-rs684559) were reported to be associated with survival after PDAC resection. We attempted to replicate the associations in 1856 PDAC patients (685 resected with stage I/II) from the PANcreatic Disease ReseArch (PANDoRA) consortium. We also analysed the combined effect of the two genotypes in order to compare our results with what was previously reported. Additional stratified analyses considering TNM stage of the disease and whether the patients received surgery were also performed. We observed no statistically significant associations, except for the heterozygous carriers of CD44-rs353630, who were associated with worse OS (HR = 5.01; 95% CI 1.58-15.88; p = 0.006) among patients with stage I disease. This association is in the opposite direction of those reported previously, suggesting that data obtained in such small subgroups are hardly replicable and should be considered cautiously. The two polymorphisms combined did not show any statistically significant association. Our results suggest that the effect of CD44-rs353630 and CHI3L2-rs684559 cannot be generalized to all PDAC patients.

CD44 polymorphisms and its variants, as an inconsistent marker in cancer investigations

Among cell surface markers, CD44 is considered the main marker for identifying and isolating the cancer stem cells (CSCs) among other cells and has attracted significant attention in a variety of research areas. Many studies have shown the essential roles of CD44 in initiation, metastasis, and tumorigenesis in different types of cancer; however, the validity of CD44 as a therapeutic or diagnostic target has not been fully confirmed in some other studies. Whereas the association of specific single nucleotide polymorphisms (SNPs) in the CD44 gene and related variants with cancer risk have been observed in clinical investigations, the significance of these findings remains controversial. Here, we aimed to provide an up-to-date overview of recent studies on the association of CD44 polymorphisms and its variants with different kinds of cancer to determine whether or not it can be used as an appropriate candidate for cancer tracking.

Extracellular HMGB1 promotes CD44 expression in hepatocellular carcinoma via regulating miR-21

As a member of damage-associated molecular patterns (DAMPs), extracellular high-mobility group box 1 (HMGB1) plays a critical role in hepatocellular carcinoma (HCC) progression. Cluster differentiation 44 (CD44) has been demonstrated to participate in HCC progression. However, the relationship between extracellular HMGB1 and CD44 remains unclear. In this study, our results indicated that extracellular HMGB1 promoted the invasion, sphere formation and EMT process of HCC by increasing CD44 expression, which was dependent on miR-21. Moreover, miR-21 upregulated CD44 expression via activating OCT4/TGF-β1 signaling. Finally, we demonstrated the activation of Rage/JNK signaling caused by extracellular HMGB1 was responsible for miR-21 overexpression. Together, these findings reveal an important role of extracellular HMGB1 in HCC progression through upregulating miR-21/CD44.

Biological characteristics and metabolic profile of canine mesenchymal stem cells isolated from adipose tissue and umbilical cord matrix

Despite the increasing demand of cellular therapies for dogs, little is known on the differences between adult and fetal adnexa canine mesenchymal stem cells (MSCs), and data on their metabolic features are lacking. The present study aimed at comparing the characteristics of canine adipose tissue (AT) and umbilical cord matrix (UC) MSCs. Moreover, for the first time in the dog, the cellular bioenergetics were investigated by evaluating the two main metabolic pathways (oxidative phosphorylation and glycolysis) of ATP production. Frozen-thawed samples were used for this study. No differences in mean cell proliferation were found (P>0.05). However, while AT-MSCs showed a progressive increase in doubling time over passages, UC-MSCs showed an initial post freezing-thawing latency. No differences in migration, spheroid formation ability, and differentiation potential were found (P>0.05). RT-PCR analysis confirmed the expression of CD90 and CD44, the lack of CD14 and weak expression of CD34, mostly by AT-MSCs. DLA-DRA1 and DLA-DQA1 were weakly expressed only at passage 0 by UC-MSCs, while they were expressed at different passages for AT-MSCs. There was no difference (P>0.05) in total ATP production between cell cultures, but the ratio between the “mitochondrial ATP Production Rate” and the “glycolytic ATP Production Rate” was higher (P<0.05) in AT- than in UC-MSCs. However, in both MSCs types the mitochondrial respiration was the main pathway of ATP production. Mitochondrial respiration and ATP turnover in UC-MSCs were higher (P<0.05) than in AT-MSCs, but both had a 100% coupling efficiency. These features and the possibility of increasing the oxygen consumption by a spare respiratory capacity of four (AT-MSCSs) and two (UC-MSCs) order of magnitude greater than basal respiration, can be taken as indicative of the cell propensity to differentiate. The findings may efficiently contribute to select the most appropriate MSCs, culture and experimental conditions for transplantation experiments in mesenchymal stem cell therapy for companion animals.

Evaluation of Apoptosis, Proliferation, and Adhesion Molecule Expression in Trophoblastic Tissue of Women With Recurrent Spontaneous Abortion and Infected With Toxoplasma gondii

Recurrent spontaneous abortion is an obstetric complication with undefined causes. Apoptosis, proliferation, and adhesion are considered important factors in the pathogenesis of abortion. This work aimed to determine Bax and Bcl-2 as a proapoptotic and antiapoptotic protein, Ki67 and P27kip as proliferative and antiproliferative proteins, and E-cadherin and CD44 as adhesion molecules in the trophoblastic tissues in cases with recurrent miscarriage. Immunohistochemistry and quantitative polymerase chain reaction analysis of Bax, Bcl-2, Ki67, P27kip, E-cadherin, and CD44 in paraffin-embedded sections of placental tissues obtained from 108 women were divided into 3 categories: 66 Toxoplasma gondii-positive women with recurrent abortion, 22 T. gondii-negative women with recurrent abortion, and 20 women with no history of abortion as a control group. The mean ratio of the expression of Bax and P27kip proteins was 35.3% and 36.1%, which is significantly higher than that of the second group (19.88 and 20.02%), and the third group (12.3% and 10.98%), while the mean ratio of the expression of Bcl-2, Ki67, E-cadherin, and CD44 proteins was 12.35%, 11.23%, 10.32%, and 9.97%, which is significantly lower than that of the second group (33.75%, 13.18%, 21.88%, and 23.29%) and that of the third group (38.58%, 39.27%, 37.98%, and 35.79%). The presence of proapoptotic protein (Bax) and antiproliferative protein (P27kip) at high levels and the presence of antiapoptotic protein (Bcl-2), proliferative protein (Ki67), and adhesion molecules (E-cadherin and CD44) in lower levels in the T. gondii-positive group clarify the mechanism involved in the induction of abortion and loss of pregnancy.

Lactobacillus acidipiscis Induced Regulatory Gamma Delta T Cells and Attenuated Experimental Autoimmune Encephalomyelitis

Multiple sclerosis is a chronic autoimmune disease involving the central nervous system, and shows a high disability rate. Its pathogenesis is complicated, and there is no good treatment. In recent years, with in-depth studies on the regulation of gastrointestinal flora, the relationship between the mammalian immune system and the intestinal flora has been extensively explored. Changes in the composition and structure of the gastrointestinal flora can affect the characteristics and development of the host immune system and even induce a series of central nervous system inflammation events. The occurrence and development of multiple sclerosis are closely related to the continuous destruction of the intestinal barrier caused by intestinal dysbacteriosis. In this study, we analyzed Lactobacillus acidipiscis in a mouse model of experimental autoimmune encephalomyelitis (EAE). We found that the amount of L. acidipiscis in the intestinal tract was inversely proportional to the progress of EAE development. In addition, the number of CD4+ FOXP3+ regulatory T cells in the mesenteric lymph nodes of mice increased significantly after the mice were fed with L. acidipiscis, and the differentiation of CD4+ T cells to Th1 and Th17 cells was inhibited. However, the protective effect of L. acidipiscis was lost in γδ T cell-deficient mice and hence was concluded to depend on the presence of regulatory γδ T cells in the intestinal epithelium. Moreover, including L. acidipiscis enhanced the development of Vγ1+γδ T cells but suppressed that of Vγ4+γδ T cells. In summary, our results demonstrated the ability of L. acidipiscis to induce generation of regulatory γδ T cells that suppress the development of the encephalomyelitic Th1 and Th17 cells and the progress of EAE.

Time-Course Changes of Extracellular Matrix Encoding Genes Expression Level in the Spinal Cord Following Contusion Injury-A Data-Driven Approach

The involvement of the extracellular matrix (ECM) in lesion evolution and functional outcome is well recognized in spinal cord injury. Most attention has been dedicated to the “core” area of the lesion and scar formation, while only scattered reports consider ECM modification based on the temporal evolution and the segments adjacent to the lesion. In this study, we investigated the expression profile of 100 genes encoding for ECM proteins at 1, 8 and 45 days post-injury, in the spinal cord segments rostral and caudal to the lesion and in the scar segment, in a rat model. During both the active lesion phases and the lesion stabilization, we observed an asymmetric gene expression induced by the injury, with a higher regulation in the rostral segment of genes involved in ECM remodeling, adhesion and cell migration. Using bioinformatic approaches, the metalloproteases inhibitor Timp1 and the hyaluronan receptor Cd44 emerged as the hub genes at all post-lesion times. Results from the bioinformatic gene expression analysis were then confirmed at protein level by tissue analysis and by cell culture using primary astrocytes. These results indicated that ECM regulation also takes place outside of the lesion area in spinal cord injury.

Lymphatic metastasis-related TBL1XR1 enhances stemness and metastasis in gastric cancer stem-like cells by activating ERK1/2-SOX2 signaling

The poor prognosis of gastric cancer (GC) results largely from metastasis and chemotherapy resistance. Toward novel therapeutic strategies that target or evade these phenomena, we evaluated the function of the transcriptional regulator transducin (β)-like 1 X-linked receptor 1 (TBL1XR1) in GC cells, including stem-like cells. In this study, the correlation of expression of TBL1XR1 and clinical features and GC patients' outcomes was evaluated. Knockdown or exogenous expression of TBL1XR1 was combined with in vitro (2D and 3D cultures) and in vivo (mouse lung and lymphatic metastasis models) assays to evaluate the function of TBL1XR1. TBL1XR1's downstream signaling was delineated by phospho-kinase array and knockdown of candidate mediators. Analysis of clinical data showed that TBL1XR1 overexpression was correlated with worse prognosis. Functional assays showed that TBL1XR1 promoted stemness, epithelial-mesenchymal transition (EMT), and lung and lymphatic metastasis in GC cells. TBL1XR1 activated ERK1/2-Sox2 signaling and was dependent on signaling via PI3K/AKT, in GC stem-like cells distinguished by CD44 expression. Moreover, inhibition of these signaling proteins reversed chemoresistance in in vitro and in vivo models. Taken together, our results indicate that TBL1XR1 promotes stemness and metastasis in GC, making it a potential prognostic indicator. The PI3K/AKT-TBL1XR1-ERK1/2-Sox2 axis may represent a target for the treatment of GC.

TGF-β1 promotes epithelial-to-mesenchymal transition and stemness of prostate cancer cells by inducing PCBP1 degradation and alternative splicing of CD44

CD44 is a marker of cancer stem cell (CSC) in many types of tumors. Alternative splicing of its 20 exons generates various CD44 isoforms that have different tissue specific expression and functions, including the CD44 standard isoform (CD44s) encoded by the constant exons and the CD44 variant isoforms (CD44v) with variant exon insertions. Switching between the CD44v and CD44s isoforms plays pivotal roles in tumor progression. Here we reported a novel mechanism of CD44 alternative splicing induced by TGF-β1 and its connection to enhanced epithelial-to-mesenchymal transition (EMT) and stemness in human prostate cancer cells. TGF-β1 treatment increased the expression of CD44s and N-cadherin while decreased the expression of CD44v and E-cadherin in DU-145 prostate cancer cells. Other EMT markers and cancer stem cell markers were also upregulated after TGF-β1 treatment. RNAi knockdown of CD44 reversed the phenotype, which could be rescued by overexpressing CD44s but not CD44v, indicating the alternatively spliced isoform CD44s mediated the activity of TGF-β1 treatment. Mechanistically, TGF-β1 treatment induced the phosphorylation, poly-ubiquitination, and degradation of PCBP1, a well-characterized RNA binding protein known to regulate CD44 splicing. RNAi knockdown of PCBP1 was able to mimic TGF-β1 treatment to increase the expression of CD44s, as well as the EMT and cancer stem cell markers. In vitro and in vivo experiments were performed to show that CD44s promoted prostate cancer cell migration, invasion, and tumor initiation. Taken together, we defined a mechanism by which TGF-β1 induces CD44 alternative splicing and promotes prostate cancer progression.

HER2 overexpression triggers the IL-8 to promote arsenic-induced EMT and stem cell-like phenotypes in human bladder epithelial cells

Arsenic is a natural chemical element that is strongly associated with bladder cancer. Understanding the underlying mechanisms behind the association between arsenic and bladder cancer as well as identifying effective preventive interventions will help reduce the incidence and mortality of this disease. The epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties play key roles in cancer development and progression. Here, we reported that chronic exposure to arsenic resulted in EMT and increased levels of the CSC marker CD44 in human uroepithelial cells. Furthermore, IL-8 promoted a mesenchymal phenotype and upregulated CD44 by activating the ERK, AKT and STAT3 signaling. Phosphorylation of the human epidermal growth factor receptor 2 (HER2) was key for arsenic-induced IL-8 overexpression and depended on the simultaneous activation of the MAPK, JNK, PI3K/AKT and GSK3β signaling pathways. We also found that genistein inhibited arsenic-induced HER2 phosphorylation and downregulated its downstream signaling pathways, thereby inhibiting progression of EMT, and reducing CD44 expression levels. These results demonstrate that the HER2/IL-8 axis is related to the acquisition of an EMT phenotype and CSCs in arsenic-treated cells. The inhibitory effects of genistein on EMT and CSCs provide a new perspective for the intervention and potential chemotherapy against arsenic-induced bladder cancer.

Hyaluronic acid engrafted metformin loaded graphene oxide nanoparticle as CD44 targeted anti-cancer therapy for triple negative breast cancer

BACKGROUND

Triple negative breast cancer (TNBC) is the most aggressive form of breast cancer with limited treatment modalities. It is associated with high propensity of cancer recurrence.

METHODS

UV Spectroscopy, FTIR, DLS, Zeta potential, TEM and SEM were employed to characterize nanoparticles. MTT assay, Wound healing assay, SEM, Immunocytochemistry analysis, Western blot, RT-PCR, mammosphere formation assay were employed to study apoptosis, cell migration and stemness. Tumor regression was studied in chick embryo xenograft and BALB/c mice model.

RESULTS

Hylaluronic acid engrafted metformin loaded graphene oxide (HA-GO-Met) nanoparticles exhibited an anti-cancer efficacy at much lower dosage as compared to metformin alone. HA-GO-Met nanoparticles induced apoptosis and inhibited cell migration of TNBC cells by targeting miR-10b/PTEN axis via NFkB-p65. Upregulation of PTEN affected pAKT(473) expression that induced apoptosis. Cell migration was inhibited by reduction of pFAK/integrinβ1 expressions. Treatment inhibited epithelial mesenchymal transition (EMT) and reduced stemness as evident from the increase in E-cadherin expression, inhibition of mammosphere formation and low expression levels of stemness markers including nanog, oct4 and sox2 as compared to control. Moreover, tumor regression was studied in chick embryo xenograft and BALB/c mice model. HA-GO-Met nanoparticle treatment reduced tumor load and nullified toxicity in peripheral organs imparted by tumor.

CONCLUSIONS

HA-GO-Met nanoparticles exhibited an enormous anti-cancer efficacy in TNBC in vitro and in vivo.

GENERAL SIGNIFICANCE

HA-GO-Met nanoparticles induced apoptosis and attenuated cell migration in TNBC. It nullified overall toxicity imparted by tumor load. It inhibited EMT and reduced stemness and thereby addressed the issue of cancer recurrence.

Role of A Novel Angiogenesis FKBPL-CD44 Pathway in Preeclampsia Risk Stratification and Mesenchymal Stem Cell Treatment

CONTEXT

Preeclampsia is a leading cardiovascular complication in pregnancy lacking effective diagnostic and treatment strategies.

OBJECTIVE

To investigate the diagnostic and therapeutic target potential of the angiogenesis proteins, FK506-binding protein like (FKBPL) and CD44.

DESIGN AND INTERVENTION

FKBPL and CD44 plasma concentration or placental expression were determined in women pre- or postdiagnosis of preeclampsia. Trophoblast and endothelial cell function was assessed following mesenchymal stem cell (MSC) treatment and in the context of FKBPL signaling.

SETTINGS AND PARTICIPANTS

Human samples prediagnosis (15 and 20 weeks of gestation; n ≥ 57), or postdiagnosis (n = 18 for plasma; n = 4 for placenta) of preeclampsia were used to determine FKBPL and CD44 levels, compared to healthy controls. Trophoblast or endothelial cells were exposed to low/high oxygen, and treated with MSC-conditioned media (MSC-CM) or a FKBPL overexpression plasmid.

MAIN OUTCOME MEASURES

Preeclampsia risk stratification and diagnostic potential of FKBPL and CD44 were investigated. MSC treatment effects and FKBPL-CD44 signaling in trophoblast and endothelial cells were assessed.

RESULTS

The CD44/FKBPL ratio was reduced in placenta and plasma following clinical diagnosis of preeclampsia. At 20 weeks of gestation, a high plasma CD44/FKBPL ratio was independently associated with the 2.3-fold increased risk of preeclampsia (odds ratio = 2.3, 95% confidence interval [CI] 1.03-5.23, P = 0.04). In combination with high mean arterial blood pressure (>82.5 mmHg), the risk further increased to 3.9-fold (95% CI 1.30-11.84, P = 0.016). Both hypoxia and MSC-based therapy inhibited FKBPL-CD44 signaling, enhancing cell angiogenesis.

CONCLUSIONS

The FKBPL-CD44 pathway appears to have a central role in the pathogenesis of preeclampsia, showing promising utilities for early diagnostic and therapeutic purposes.

The p53-induced RNA-binding protein ZMAT3 is a splicing regulator that inhibits the splicing of oncogenic CD44 variants in colorectal carcinoma

p53 is an intensely studied tumor-suppressive transcription factor. Recent studies suggest that the RNA-binding protein (RBP) ZMAT3 is important in mediating the tumor-suppressive effects of p53. Here, we globally identify ZMAT3-regulated RNAs and their binding sites at nucleotide resolution in intact colorectal cancer (CRC) cells. ZMAT3 binds to thousands of mRNA precursors, mainly at intronic uridine-rich sequences and affects their splicing. The strongest alternatively spliced ZMAT3 target was CD44, a cell adhesion gene and stem cell marker that controls tumorigenesis. Silencing ZMAT3 increased inclusion of CD44 variant exons, resulting in significant up-regulation of oncogenic CD44 isoforms (CD44v) and increased CRC cell growth that was rescued by concurrent knockdown of CD44v Silencing p53 phenocopied the loss of ZMAT3 with respect to CD44 alternative splicing, suggesting that ZMAT3-mediated regulation of CD44 splicing is vital for p53 function. Collectively, our findings uncover a p53-ZMAT3-CD44 axis in growth suppression in CRC cells.

Expressions of CD44, PCNA and MRP1 in lung cancer tissues and their effects on proliferation and invasion abilities of lung cancer cell line 95D

PURPOSE

To investigate the expressions of CD44 non-small cell lung cancer cells, proliferating cell nuclear antigen (PCNA) and multidrug resistance-associated protein 1 (MRP1) in the lung cancer tissues and their effects on the proliferation and invasion abilities in vitro of lung cancer cell line 95D.

METHODS

138 lung cancer tissues and 127 adjacent normal tissues were collected from lung cancer patients after operation in Shandong Provincial Third Hospital from January 2015 to December 2017. CD44 siRNA (experimental CD44 group), PCNA siRNA (experimental PCNA group) and MRP1 siRNA (experimental MRP1 group) were transfected into human lung cancer 95D cells, and a negative control group (cells transfected with miR-Native Control) and a blank group (untransfected cells) were established. MTT assay was used for detecting the proliferation of cells, and Transwell chamber was used for detecting their invasion ability.

RESULTS

The relative expressions of CD44, PCNA and MRP1 in the lung cancer tissues were higher than those in the adjacent tissues (p<0.050). At 24th h, the cell survival rate in the experimental MRP1 group was lower than that in the experimental PCNA group (p<0.050); At 48th the cell survival rate in the experimental MRP1 group was higher than that in the experimental CD44 group (p<0.050). At 72th h, the cell survival rate in the experimental PCNA group was significantly higher than that in the experimental CD44 group and the experimental MRP1 group (p<0.05). The cell invasion number in the experimental CD44 group, the experimental PCNA group and the experimental MRP1 group were significantly lower than cells in the negative control group and blank group (p<0.05).

CONCLUSION

CD44, PCNA and MRP1, which may be involved in the regulation of the proliferation and invasion abilities of lung cancer cells, may serve as new molecular targeting markers for the diagnosis and treatment of lung cancer.

Cell-free DNA promotes malignant transformation in non-tumor cells

Cell-free DNA is present in different biological fluids and when released by tumor cells may contribute to pro-tumor events such as malignant transformation of cells adjacent to the tumor and metastasis. Thus, this study analyzed the effect of tumor cell-free DNA, isolated from the blood of prostate cancer patients, on non-tumor prostate cell lines (RWPE-1 and PNT-2). To achieve this, we performed cell-free DNA quantification and characterization assays, evaluation of gene and miRNA expression profiling focused on cancer progression and EMT, and metabolomics by mass spectrometry and cellular migration. The results showed that tumor-free cell DNA was able to alter the gene expression of MMP9 and CD44, alter the expression profile of nine miRNAs, and increased the tryptophan consumption and cell migration rates in non-tumor cells. Therefore, tumor cell-free DNA was capable of altering the receptor cell phenotype, triggering events related to malignant transformation in these cells, and can thus be considered a potential target for cancer diagnosis and therapy.

Patient-derived and artificial ascites have minor effects on MeT-5A mesothelial cells and do not facilitate ovarian cancer cell adhesion

The presence of ascites in the peritoneal cavity leads to morphological and functional changes of the peritoneal mesothelial cell layer. Cells loose cell-cell interactions, rearrange their cytoskeleton, activate the production of fibronectin, and change their cell surface morphology in a proinflammatory environment. Moreover, ovarian cancer cell adhesion has been shown to be facilitated by these changes due to increased integrin- and CD44-mediated binding sites. In this study, the biological responsiveness of the human pleural mesothelial cell line MeT-5A to patient-derived and artificial ascites was studied in vitro and adhesion of ovarian cancer cells, i.e. SKOV-3 cells, investigated. Changes were mainly observed in cells exposed to artificial ascites containing higher cytokine concentrations than patient-derived ascites. Interestingly, reduced cell-cell interactions were already observed in untreated MeT-5A cells and effects on tight junction protein expression and permeability upon exposure to ascites were minor. Ascites induced upregulation of CDC42 effector protein 2 expression, which affects stress fiber formation, however significant F-actin reorganization was not observed. Moreover, fibronectin production remained unchanged. Analysis of mesothelial cell surface characteristics showed upregulated expression of intercellular adhesion molecule 1, slightly increased hyaluronic acid secretion and decreased microvillus expression upon exposure to ascites. Nevertheless, the observed changes were not sufficient to facilitate adhesion of SKOV-3 cells on MeT-5A cell layer. This study revealed that MeT-5A cells show a reduced biological responsiveness to the presence of ascites, in contrast to published studies on primary human peritoneal mesothelial cells.