CD44 Variant Research Articles

Clinicopathological significance and prognostic implication of CD44 and its splice variants (v3 and v6) in colorectal cancer.

BackgroundCD44 is a marker for colorectal cancer (CRC) stem cells (CCSCs), but its prognostic value remains controversial. Furthermore, few studies have investigated the expression profile of CD44 variants in CRC. The proto-oncogene mast/stem cell growth factor receptor Kit (c-Kit) was previously found to play an important role in supporting CRC cells; however, the associations between c-Kit and CD44 (and its splice variants) remain largely unknown.MethodsA total of 148 patients with CRC were enrolled in the present study, and the levels of CD44, CD44 splice variant (v)3, CD44v6 and c-Kit were examined by immunohistochemical staining. Associations between these markers and clinicopathological parameters, as well as the extent to which these markers predict progression free-survival (PFS), were analyzed.ResultsA total of 29 (19.6%), 60 (40.5%) and 66 (44.6%) patients were CD44-, CD44v3- and CD44v6-positive, respectively. No clear c-Kit-positivity was detected in any of the patients. Analyses of clinicopathological features indicated that positive expression of CD44v3 was significantly associated with cell differentiation (P=0.03), and N (P=0.04), M (P<0.01) and tumor-node-metastasis (TNM) stages (P<0.01). Univariate analysis demonstrated that T, N, M and TNM stages (all P<0.01), and CD44 (P<0.01), CD44v3 (P=0.03) and CD44v6 (P=0.02) levels were significantly associated with PFS. Furthermore, multivariate analysis indicated that patients without CD44 expression (P<0.01) but with CD44v3 (P=0.04) and CD44v6 (P=0.02) expression exhibited significantly shortened PFS.ConclusionsCD44, CD44v3 and CD44v6 were determined to be heterogeneously expressed in CRC, and may aid in the prognostic prediction of patients with this disease.

18 A HUMAN-DERIVED 5-MER PEPTIDE (MTADV), WHICH RESTRICTIVELY ALLEVIATES THE PRO-INFLAMMATORY ACTIVITY OF SERUM AMYLOID A (SAA), SUBSTANTIALLY AMELIORATES IBD PATHOLOGY: NEW POTENTIAL DRUG (MTADV) AND THERAPEUTIC TARGET CANDIDATE (SAA) FOR IBD

Abstract A human anti-inflammatory 5-MER peptide MTADV (methionine-threonine-alanine-aspartic acid-valine) derived from a sequence of a pro-inflammatory CD44 variant was first described by us in Nedvetzki et al., J. Clin. Invest. 111,1211-1220, 2003. A NCBI BLAST RefSeq protein sequence database, that contains at present 81,347 human protein sequences, reveals that only one additional protein contains this unique MTADV sequence of alternating hydrophobic and hydrophilic amino acids. This human peptide displays an efficient anti-inflammatory effect in Inflammatory Bowel Disease (IBD), Rheumatoid Arthritis and Multiple sclerosis mouse models, all share amyloid proteins in the relevant target organs. We show here that the 5-MER peptide, administered after the onset of disease,either by SC injections or oral delivery, inhibited the pathological activity of two IBD models (TNBS and DSS), as indicated by histopathology analysis (Ameho’s score) or Bioluminescence Imaging, sensing the release of Reactive Oxdative Species (ROS), which reflect colon inflammation (Fig 1). The 5-MER MTADV peptide, while inhibiting chronic inflammation, neither interferes with normal immune responses nor induce neutralizing antibodies. A pull-down experiment with mass spectrometric analysis revealed that the 5-MER peptide specifically binds to serum amyloid A (SAA), a stress pro-inflammatory protein, which generates aggregated amyloid deposits in the IBD colon (de Villiers at al Cytokine 12:1337-1347,2000). Our studies further provide in vitro evidence, strengthened by in vivo experiments, that SAA is a significant target of this pentamer. To this end, the 5-MER peptide (but not the corresponding scrambled peptide) inhibits the release of the pro-inflammatory cytokines IL-6 and IL-1β from SAA-activated fibroblasts. Furthermore, the 5-MER peptide was found to retard the early stages of amyloid-type aggregation of SAA in solution (Fig 2). Adopting the β-sheet conformation, MTADV would display opposing hydrophobic and hydrophilic faces that could interact with the β-sheet-forming amyloidogenic sequences in SAA. This suggests that the mechanism of action for the 5-MER peptide in vivo may depend on its ability to slow the aggregation of SAA, thus reduce its contribution to chronic inflammation. Finally, using bioinformatics and qRT-PCR, we have found the pentamer up-regulates set of genes involved in resistance to chronic inflammations. Hence, our study provides both a new potential drug (MTADV) and a new therapeutic target candidate (SAA) for IBD.

Impact of Truncated O-glycans in Gastric-Cancer-Associated CD44v9 Detection.

CD44 variant isoforms are often upregulated in cancer and associated with increased aggressive tumor phenotypes. The CD44v9 is one of the major protein splice variant isoforms expressed in human gastrointestinal cancer cells. Immunodetection of CD44 isoforms like CD44v9 in tumor tissue is almost exclusively performed by using specific monoclonal antibodies. However, the structural variability conferred by both the alternative splicing and CD44 protein glycosylation is disregarded. In the present work, we have evaluated the role of O-glycosylation using glycoengineered gastric cancer models in the detection of CD44v9 by monoclonal antibodies. We demonstrated, using different technical approaches, that the presence of immature O-glycan structures, such as Tn and STn, enhance CD44v9 protein detection. These findings can have significant implications in clinical applications mainly at the detection and targeting of this cancer-related CD44v9 isoform and highlight the utmost importance of considering glycan structures in cancer biomarker detection and in therapy targeting.

CD44 variant 6 is associated with prostate cancer growth and chemo-/radiotherapy response in vivo

We have previously demonstrated that CD44 variant 6 (CD44v6) is associated with prostate cancer (CaP) growth and therapeutic resistance in vitro, however, the role of CD44v6 in CaP in vivo is not fully understood. The purpose of this study is to investigate the effect of CD44v6 on CaP growth and chemo−/radiotherapy response in NOD/SCID mouse models in vivo and to validate its role as a therapeutic target for CaP therapy. CD44v6 was knocked down in PC-3M CaP cell line using short hairpin RNA. Subcutaneous (s.c.) and orthotopic CaP mouse xenografts were established. The effect of CD44v6 knockdown (KD) on tumour growth was evaluated in both s.c. and orthotopic models. Chemo−/radiotherapy response was evaluated in the s.c. model. Association of CD44v6 with PI3K/Akt pathway was validated using immunohistochemistry staining. We found that KD of CD44v6 significantly reduced tumour growth in both models, and enhanced the sensitivity of tumours to chemotherapy and radiotherapy in the s.c. model. In addition, we demonstrated that KD of CD44v6 is associated with downregulation of the PI3K/Akt/mTOR pathway. Our data confirm that CaP growth and chemo−/radiosensitivity in vivo is associated with CD44v6, which holds great promises as a therapeutic target in the treatment of CaP.

CD44 Genotypes Are Associated with Susceptibility and Tumor Characteristics in Colorectal Cancer Patients.

Colorectal cancer is the third cause of cancer and the second leading cause of death worldwide. The CD44 gene plays a key role in malignant processes, including growth, survival, epithelial to mesenchymal transition and metastasis. It is also known that some variants as rs187116 (c.67+4883G>A) and rs7116432 (c.2024+779A>G) can modulate the function of the CD44 gene and malignant transformation in several neoplasms. This study aims to explore, for the first time, the association of the CD44 rs187116 and rs7116432 variants in patients with colorectal cancer. Genomic DNA from 250 patients and 250 healthy blood donors were analyzed. The identification of variants was made by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. Association was calculated by the odds ratio (OR) test and multivariate analysis. Individuals carrying the G/A and A/A genotypes for the rs187116 polymorphism showed an increased risk for colorectal cancer (OR = 3.11, 95% CI: 1.87-5.16, P = 0.001 and OR = 3.59, 95% CI: 2.06-6.25, P = 0.001, respectively). After adjusting for age and gender, these same genotypes and the G/G genotype of the rs7116432 polymorphism were associated with TNM stage and tumor location in the colon. Moreover, the A-G (rs187116 and rs7116432) haplotype was associated with increased risk; while, the haplotype G-A (rs187116 and rs7116432) was related with decreased risk. In conclusion, our results suggest that the here analyzed CD44 variants are involved with risk, TNM stage and tumor location in colorectal cancer.

Glutaminolysis-related genes determine sensitivity to xCT-targeted therapy in head and neck squamous cell carcinoma.

Targeting the function of membrane transporters in cancer stemlike cells is a potential new therapeutic approach. Cystine‐glutamate antiporter xCT expressed in CD44 variant (CD44v)‐expressing cancer cells contributes to the resistance to oxidative stress as well as cancer therapy through promoting glutathione (GSH)‐mediated antioxidant defense. Amino acid transport by xCT might, thus, be a promising target for cancer treatment, whereas the determination factors for cancer cell sensitivity to xCT‐targeted therapy remain unclear. Here, we demonstrate that high expression of xCT and glutamine transporter ASCT2 is correlated with undifferentiated status and diminished along with cell differentiation in head and neck squamous cell carcinoma (HNSCC). The cytotoxicity of the xCT inhibitor sulfasalazine relies on ASCT2‐dependent glutamine uptake and glutamate dehydrogenase (GLUD)‐mediated α‐ketoglutarate (α‐KG) production. Metabolome analysis revealed that sulfasalazine treatment triggers the increase of glutamate‐derived tricarboxylic acid cycle intermediate α‐KG, in addition to the decrease of cysteine and GSH content. Furthermore, ablation of GLUD markedly reduced the sulfasalazine cytotoxicity in CD44v‐expressing stemlike HNSCC cells. Thus, xCT inhibition by sulfasalazine leads to the impairment of GSH synthesis and enhancement of mitochondrial metabolism, leading to reactive oxygen species (ROS) generation and, thereby, triggers oxidative damage. Our findings establish a rationale for the use of glutamine metabolism (glutaminolysis)‐related genes, including ASCT2 and GLUD, as biomarkers to predict the efficacy of xCT‐targeted therapy for heterogeneous HNSCC tumors.

Stress-triggered YAP1/SOX2 activation transcriptionally reprograms head and neck squamous cell carcinoma for the acquisition of stemness.

The clinical importance of cancer stem cells (CSCs) in head and neck squamous cell carcinoma (HNSCC) is well recognized. However, a reliable method for the detection of functioning CSC has not yet been established. We hypothesized that YAP1, a transcriptional coactivator, and SOX2, a master transcription factor of SCC, may cooperatively induce stemness through transcriptional reprogramming. We immunohistochemically examined the expression of SOX2 and YAP1 in the CD44 variant 9 (CD44v9)-positive invasion front. A CSC-inducible module was identified through a combination of siRNAs and sphere formation assays. YAP1 and SOX2 interactions were analyzed in vitro. The triple overexpression of SOX2, YAP1, and CD44v9 was significantly associated with poor prognosis. TCGA data revealed that the CSC-inducible module, which was related to EMT and angiogenesis, was significantly correlated with poor prognosis. The KLF7 expression, representatively chosen from the module, also correlated with poor prognosis and was essential for sphere formation and CSC propagation. Sphere stress-activated YAP1 enhanced SOX2 activity. The stress-triggered activation of YAP1/SOX2 transcriptionally reprograms HNSCC for the acquisition of stemness. Triple SOX2, YAP1, and CD44v9 immunostaining assays may be useful for the selection of high-risk patients with functioning CSCs, and YAP1 targeting may lead to the development of a CSC-targeting therapy.

Endothelial-Mesenchymal Transition Drives Expression of CD44 Variant and xCT in Pulmonary Hypertension.

Pulmonary arterial hypertension (PAH) pathogenesis shares similarities with carcinogenesis. One CD44 variant (CD44v) isoform, CD44v8-10, binds to and stabilizes the cystine transporter subunit (xCT), producing reduced glutathione and thereby enhancing the antioxidant defense of cancer stem cells. Pharmacological inhibition of xCT by sulfasalazine suppresses tumor growth, survival, and resistance to chemotherapy. We investigated whether the CD44v-xCT axis contributes to PAH pathogenesis. CD44v was predominantly expressed on endothelial-to-mesenchymal transition (EndMT)-like cells in the neointimal layer of PAH affected pulmonary arterioles. In vitro, CD44 standard form and CD44v were induced as a result of EndMT. Among human pulmonary artery endothelial cells that have undergone EndMT, CD44v+ cells showed high levels of xCT expression on their cell surfaces and high concentrations of glutathione for survival. This made CD44v+ cells the most vulnerable target for sulfasalazine. CD44v+xCThi cells showed the highest expression levels of proinflammatory cytokines, antioxidant enzymes, antiapoptotic molecules, and cyclin-dependent kinase inhibitors. In the Sugen5416/hypoxia mouse model, CD44v+ cells were present in the thickened pulmonary vascular wall. The administration of sulfasalazine started either at the same time as "Sugen5416" administration (a prevention model) or after the development of pulmonary hypertension (a reversal model) attenuated the muscularization of the pulmonary vessels, decreased the expression of markers of inflammation, and reduced the right ventricular systolic pressure, while reducing CD44v+ cells. In conclusion, CD44v+xCThi cells appear during EndMT and in pulmonary hypertension tissues. Sulfasalazine is expected to be a novel therapeutic agent for PAH, most likely targeting EndMT-derived CD44v+xCThi cells.

Decrease in MiR-148a Expression During Initiation of Chief Cell Transdifferentiation.

Gastric chief cells differentiate from mucous neck cells and develop their mature state at the base of oxyntic glands with expression of secretory zymogen granules. After parietal cell loss, chief cells transdifferentiate into mucous cell metaplasia, designated spasmolytic polypeptide-expressing metaplasia (SPEM), which is considered a candidate precursor of gastric cancer. We examined the range of microRNA (miRNA) expression in chief cells and identified miRNAs involved in chief cell transdifferentiation into SPEM. Among them, miR-148a was strongly and specifically expressed in chief cells and significantly decreased during the process of chief cell transdifferentiation. Interestingly, suppression of miR-148a in a conditionally immortalized chief cell line induced up-regulation of CD44 variant 9 (CD44v9), one of the transcripts expressed at an early stage of SPEM development, and DNA methyltransferase 1 (Dnmt1), an established target of miR-148a. Immunostaining analyses showed that Dnmt1 was up-regulated in SPEM cells as well as in chief cells before the emergence of SPEM in mouse models of acute oxyntic atrophy using either DMP-777 or L635. In the cascade of events that leads to transdifferentiation, miR-148a was down-regulated after acute oxyntic atrophy either in xCT knockout mice or after sulfasalazine inhibition of xCT. These findings suggest that the alteration of miR-148a expression is an early event in the process of chief cell transdifferentiation into SPEM.

Immunohistochemical expression of CD44v9 and 8-OHdG in ovarian endometrioma and the benign endometriotic lesions adjacent to clear cell carcinoma.

Expression of CD44 variant isoforms (CD44v) promotes the synthesis of reduced glutathione and contributes to reactive oxygen species defense through up-regulation of the intracellular antioxidant. The aim of the study was to investigate the expression of CD44v9 and oxidative DNA damage marker, 8-OHdG, in benign ovarian endometrioma (OE) and OE harboring clear cell carcinomas (CCC). A retrospective study was performed at the Department of Gynecology, Nara Medical University hospital from January 2006 to December 2012. Patients with histologically confirmed benign OE (n = 27) and OE harboring areas of CCC (n = 8) were selected. Tissue samples were immunohistochemically analyzed for the presence of CD44v9 and 8-OHdG using avidin-biotin complex method. CD44v9 was located on the cell membrane of endometriotic epithelial cells and expressed in 88.9% (24/27) of benign OE tissues. Only 25.0% (2/8) of benign endometriotic lesions adjacent to CCC was found to stain weakly for CD44v9. Percentage of CD44v9 positive cells was 68.5 ± 20.2% (mean ± standard deviation) of benign OE, 16.7 ± 16.5% of CCC endometriotic tissue (P < 0.001). Compared to benign OE, CCC endometriotic tissue showed a significant increase in the proportion of 8-OHdG expression (77.3 ± 22.5% vs 94.9 ± 3.0%, P = 0.049). A significant negative correlation was observed between CD44v9 status and 8-OHdG nuclear expression (r = -0.458, P = 0.006). Alterations in CD44v9 and 8-OHdG may be associated with malignant transformation of benign OE.

Abstract 1165: Differential expression of CD44 variants drive the progression, invasion, drug-resistance and stemness characteristics in human oral squamous cell carcinoma

Abstract Purpose: Cluster of differentiation 44 (CD44) is a cell-surface glycoprotein and plays role in the progression and severity of oral squamous cell carcinoma (OSCC). Here we report differential function of CD44 variants in OSCC progression. Materials and methods: The expression of CD44 standard (CD44s) and variants (CD44v4, CD44v6); the activation of signaling pathways (MAPK, PI3K); the cell viability; and the MMP-9/-2 activity were assessed using RT-PCR, immunohistochemistry, Western blotting, MTT assay and gelatin zymography. These experiments were carried out using fresh human OSCC tissue specimens, including adjacent normal, noninvasive (N0), invasive tumor samples (N1-3) and chemo-radiation resistant tumor samples (RCRT). We also used OSCC cell lines, including parental (SCC9/SCC4) and Cisplatin-resistant (CisR-SCC9/-SCC4) to confirm our observation with human tissues. Knock down of CD44 variants or inactivation of MAPK/PI3K pathways was achieved for in vitro analysis in OSCC cells. Summary: Differential expressions of CD44 variants (v4and v6) were associated with overall oral cancer aggressiveness. CD44v4 expression was positively correlated with the activation of MAPK pathway causing chemoresistance. Conversely, CD44v6 expression and activation of PI3K-Akt caused invasiveness of OSCC. Finally, an overlapping role of two major signal transduction pathways such as MAPK and PI3K, that impinge on the variants/ isoforms expressions of a single gene i.e. CD44 that leads to the OSCC aggressiveness. Conclusion: Collectively, these results established that CD44 variants (v4and v6) expression driven by MAPK/PI3K are associated with the overall progression, drug-resistance, invasion, and stemness characteristics leading to the aggressiveness of OSCC. Hence targeting these pathways may be exploited for treating OSCC. Keywords: OSCC, CD44s, CD44v4/6, MAPK, PI3K, Notch, Chemoresistance, Invasion/migration, stemness, aggressiveness of OSCC. Note: This abstract was not presented at the meeting. Citation Format: Tanushree Kashyap, Siddavaram Nagini, Ajay Rana, Rajakishore Mishra. Differential expression of CD44 variants drive the progression, invasion, drug-resistance and stemness characteristics in human oral squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1165.

LGR5 expression predicts peritoneal recurrence after curative resection of primary colon cancer

BackgroundThe aim of this study was to clarify whether a cancer stem cell marker could be an indicator of post-operative peritoneal recurrence of colon cancer.MethodsExpression of four putative markers (CD133, CD44 variant 6, aldehyde dehydrogenase-1 and leucine-rich repeating G-protein-coupled receptor-5 (LGR5)) was evaluated immunohistochemically in primary tumour samples from 292 patients who underwent curative resection for non-metastasised pT4 colon cancer at the University of Tokyo Hospital between 1997 and 2015.ResultsPeritoneal recurrence was significantly higher in LGR5-negative cases (5-year cumulative incidence: 27.5% vs. 14.4%, p = 0.037). Multivariable analysis confirmed that negative LGR5 expression was an independent risk factor for peritoneal recurrence (hazard ratio (HR) 2.79, p = 0.005) in addition to poor differentiation, positive lymph node metastasis, preoperative carcinoembryonic antigen > 5 ng/mL and anastomotic leakage. The addition of LGR5 significantly improved the predictive value of the multivariable model (net reclassification improvement: 0.186, p = 0.028: integrated discrimination improvement: 0.047, p = 0.008).ConclusionsNegative LGR5 expression was a significant predictor of peritoneal recurrence in patients with pT4 colon cancer. Therefore, LGR5 might be a promising biomarker to identify patients at high risk of post-operative peritoneal metastasis.

Induction of CD44 Variant Isoforms is an Early Epithelial Response to Helicobacter pylori Infection

BackgroundHelicobacter pylori (H. pylori) is the major risk factor for the development of gastric cancer. The progression of H. pylori induced chronic inflammation to gastric cancer may result from the aberrant expression of the cancer stem cell marker, CD44 variant isoform 9 (CD44v9). H. pylori induces reactive oxygen species (ROS) that subsequently leads to cell apoptosis via caspase activation. It is reported that in cancer stem cells, CD44v9 stabilizes the cystine‐glutamate transporter xCT, thus promotes resistance to ROS and subsequently leads to tumor growth. However, it is unknown whether CD44v9 protects the gastric epithelium against H. pylori‐induced apoptosis during early infection. In addition, CD44 variant isoform 6 (CD44v6), is not only a biomarker for diffuse‐type gastric cancer, but also promotes H. pylori‐induced epithelial cell proliferation.HypothesesH. pylori‐induced CD44v9 is an early epithelial response to infection that subsequently promotes resistance to ROS‐induced epithelial cell apoptosis.MethodsAntral and fundic gastric organoids were generated from induced pluripotent stem cell (IPSC) lines derived from the whole blood of normal patients (HGOs). HGOs were microinjected with the H. pylori G27 or a cagA mutant strain. After 72 hr of infection organoids were immunostained for CD44v9, CD44v6 and H. pylori. The expression of IL‐8 and caspase 3 were measured by qRT‐PCR. In a separate series of experiments, infected organoids were treated with either vehicle or 300 mM sulfasalazine (SSZ) for 72 hrs and changes in phosphorylation (activation) of p38MAPK, a downstream target of ROS was measured by western blot. RNA was isolated from uninfected and infected antral and fundic HGOs and RNA‐sequencing was performed to analyze differential expression of genes among those samples.ResultsH. pylori induced the expression of CD44v9 and CD44v6 in HGOs and this correlated with the suppression of caspase 3 and increased IL‐8 gene expression. Despite the Increased expression of ROS observed in H. pylori Infected HGOs, there was increased epithelial cell proliferation within the infected organoids. Proliferation significantly decreased in H. pylori infected HGOs treated with xCT inhibitor SSZ. H. pylori infected fundic HGOs showed 94% dissimilarity in the differentially expressed genes compared to infected antral HGOs, which fall mostly in cancer and apoptotic pathways.ConclusionInduction of CD44v9 and v6 are early epithelial changes in response to H. pylori infection, and may play a role in the protection against H. pylori‐induced apoptosisSupport or Funding InformationThis work was supported by NIH 1U19AI116491‐01 (Weis and Wells, YZ Project Leader),This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Defense against Reactive Oxygen Species during Gastric Wound Repair is Mediated by the Cystine‐Glutamate xCT Transporter in Response to Injury

Background/HypothesisCluster‐of‐differentiation gene 44 (CD44) is an alternatively spliced cell surface protein. CD44 variant isoform 9 (CD44v9) has been shown to mediate gastric repair, but the precise mechanism is unknown. Reactive Oxygen Species (ROS) driven p38/MAPK signaling leads to increased caveolin‐1, and re‐direction of β‐catenin from the nucleus to the membrane where it decreases fundamental events contributing to repair such as cellular proliferation and migration. CD44v9 stabilizes the cystine‐glutamate transporter, xCT, which provides defense against ROS. Thus, we hypothesized that CD44v9 stabilizes the xCT transporter to potentiate defense against ROS to establish an environment conducive to efficient wound repair.MethodsAcetic acid injury was induced in C57BL/6 (BL6) mice followed by vehicle, sulfasalazine (SSZ, an xCT inhibitor) or glutathione inhibitor (GSHinh). Acetic acid gastric injuries were induced in aged mice (&gt;8 months) and animals were treated with p38 inhibitor. Mice were analyzed between days 1 to 30 post‐injury. A novel scratch‐wound assay generated from organoids derived from human stomachs and transferred to a gastric epithelial cell monolayer (huGEM) was treated with vehicle, SSZ or GSHinh.Results1) CD44v9 and xCT co‐expressing cells emerge at the ulcer margin: CD44v9/xCT co‐expressing cells emerged at the ulcer margin within 3‐days post‐injury. Compared to control mice, animals treated with SSZ or GSHinh showed impaired wound healing and loss of normal epithelial regeneration in response to injury. Western blots showed loss of activated β‐catenin, increased expression of caveolin‐1 that coincided with loss in repair in SSZ‐treated mice. FACS sorted CD44v9+ve cells from the ulcer margin expressed markers of EMT. 2) SSZ and GSHinh inhibited wound healing in huGEM scratch wound assays: HuGEM cultures exhibited a cellular composition reflective of primary gastric tissue that included the expression of parietal, chief, and mucous neck and pit cells. CD44v9/xCT co‐expressing cells emerged at the wound edge in huGEM cultures in response to a scratch wound. HuGEM cultures treated with SSZ or GSHinh exhibited significantly delayed wound closure. 3) p38 inhibitor rescues wound healing in vivo in the stomachs of aged mice: In human gastric biopsies, CD44v9, xCT, and activated β‐catenin was significantly decreased in elderly patients. Aged mice treated with p38 inhibitor displayed increased cellular proliferation, CD44v9 expression, and rescued repair when compared to aged vehicle controls.ConclusionCD44v9 and xCT emerge during gastric regeneration which may potentiate defense against ROS to allow for effective healing.Support or Funding InformationR01 DK083402‐06A1This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Cancer stem cell-associated miRNAs serve as prognostic biomarkers in colorectal cancer.

Chemoresistance in cancer is linked to a subset of cancer cells termed "cancer stem cells" (CSCs), and in particular, those expressing the CD44 variant appear to represent a more aggressive disease phenotype. Herein, we demonstrate that CD44v6 represents a CSC population with increased resistance to chemotherapeutic agents, and its high expression is frequently associated with poor overall survival (OS) and disease-free survival (DFS) in patients with colorectal cancer (CRC). CD44v6+ cells showed elevated resistance to chemotherapeutic drugs and significantly high tumor initiation capacity. Inhibition of CD44v6 resulted in the attenuation of self-renewal capacity and resensitization to chemotherapeutic agents. Of note, miRNA profiling of CD44v6+ spheroid-derived CSCs identified a unique panel of miRNAs indicative of high self-renewal capacity. In particular, miR-1246 was overexpressed in CD44v6+ cells, and associated with poor OS and DFS in CRC patients. We demonstrate that CD44v6+ CSCs induced chemoresistance and enhance tumorigenicity in CRC cells, and this was in part orchestrated by a distinct panel of miRNAs with dysregulated profiles. These findings suggest that specific miRNAs could serve as therapeutic targets as well as promising prognostic biomarkers in patients with colorectal neoplasia.

3332 Overexpression of CD44 is involved in the development of the early endometriotic lesion in a xenograft model

OBJECTIVES/SPECIFIC AIMS: Previously, we showed decreased development of endometriotic lesions in CD44 knockout mice compared to control.(1) CD44 has 10 different variants and a standard form. Menstrual endometrial cells (MECs) from women with endometriosis have increased adhesion and also express higher levels of CD44 variant 6 (v6) than v3, compared to MECs from women without endometriosis. (2) Here, we assessed the effects of CD44 standard (CD44s), CD44v3 and CD44v6 overexpression (OE) on immortalized human endometrial epithelial (iEECs) and stroma cells (hESCs) in vivo attachment in a nude mouse xenograft model. 1. Knudtson JF, Tekmal RR, Santos MT, et al. Impaired Development of Early Endometriotic Lesions in CD44 Knockout Mice. Reproductive sciences (Thousand Oaks, Calif.). 2016;23(1):87-91. 2. Griffith JS, Liu YG, Tekmal RR, Binkley PA, Holden AE, Schenken RS. Menstrual endometrial cells from women with endometriosis demonstrate increased adherence to peritoneal cells and increased expression of CD44 splice variants. Fertility and sterility. 2010;93(6):1745-1749. METHODS/STUDY POPULATION: Overexpression of CD44s, CD44v3 and CD44v6 was carried out using lipofectamine and their expression verified with qRT-PCR in iEEC and hESCs. Nude mice, 8-10 week old, were injected with estrogen 1 week prior to injection of iEECs and hESCs (n=7 per group). The cells were counted after transfection and at least 300,000 iEECs and 300,000 hESCs were injected per mouse. The transfected cells were tagged with cell tracker red (iEECs) and green (hESCs). Forty-eight hours after injection into the xenograft, the mice were sacrificed. The cells were counted using fluorescent stereo microscopy (FSM). Percent attachment was calculated based on the number of cells visualized by FSM divided by the number of transfected cells injected. Unpaired student t-test was performed to analyze differences in the percent attachment of the cells. RESULTS/ANTICIPATED RESULTS: The majority of cells were attached to the peritoneum. There was increased attachment of hESCs with OE of CD44v6 compared to control (p=0.03). CD44v6 OE did not change attachment of iEECs. There was no difference in attachment in iEECs or hESCs with OE of CD44s or CD44v3. DISCUSSION/SIGNIFICANCE OF IMPACT: Overexpression of CD44v6 increases attachment of ESCs to PMCs in an in vivo xenograft model. Menstrual endometrial cell type and CD44 variants play a complex role in the development of the early endometriotic lesion.

The Use of CD44 Variant 9 and Ki-67 Combination Can Predicts Prognosis Better Than Their Single Use in Early Gastric Cancer.

PurposeWe previously demonstrated that CD44v9 and Ki-67 played an important role in predicting poor prognosis of early gastric cancer (EGC). However, little is known about combined use of both biomarkers as prognostic biomarker. The present study was performed to investigate the significance of CD44v9 and Ki-67 expression as a combination biomarker for EGC.Materials and MethodsWith tissue microarray for 158 EGC tissues, we performed immunohistochemical staining for CD44v9 and Ki-67. The whole patients were divided into three groups (group A, CD44v9-negative/Ki-67–low; group B, neither group A or C; and group C, CD44v9-positive/Ki-67–high). Its clinical significance was re-analyzed with adjustment via propensity score matching (PSM). For validation, we performed bootstrap resampling.ResultsThe median follow-up duration was 90.4 months (range, 3.7 to 120.4 months). In the comparison according to CD44v9/Ki-67 expression, the combined use of the two biomarker clearly separated the three groups by 5-year survival rates (5-YSR, 96.3%, 89.8%, and 76.8% in group A, B, and C, respectively; p=0.009). After PSM, 5-YSR were 97.7% and 76.8% in group A+B and group C, respectively (p=0.002). Multivariable analysis demonstrated that group C had independently poor prognosis (hazard ratio, 9.137; 95% confidence interval, 1.187 to 70.366; p=0.034) compared with group A. Bootstrap resampling internally validated this result (p=0.016).ConclusionThis study suggests that both positive CD44v9 and high Ki-67 expression are associated with poor prognosis in EGC, and the combined use of these markers provides better prognostic stratification than the single use of them.

The Significance of CD44 Variant 9 in Resected Lung Adenocarcinoma: Correlation with Pathological Early-Stage and EGFR Mutation

CD44 isoforms serve as a marker for cancer stem cells. CD44 variant 9 (CD44v9) contributes to the defense against reactive oxygen species, resulting in resistance to chemoradiotherapy. However, the significance of CD44v9 in patients with lung adenocarcinoma is unknown. We used immunohistochemical analysis to retrospectively analyze CD44v9 expression in 268 surgically resected lung adenocarcinomas and investigated the association between CD44v9 expression and patients' clinicopathological features. The expression of CD44v9 in 193 of 268 (72.0%) patients was significantly associated with early-stage cancer, low-grade tumors, absence of vessel and pleural invasion, and a mutated epidermal growth factor receptor (EGFR) gene. Multivariate logistic analysis revealed that CD44v9 expression was significantly associated with early-stage disease [odds ratio (OR) 0.29, 95% confidence interval (CI) 0.14-0.59; p < 0.001] and mutant EGFR (OR 2.53, 95% CI 1.06-6.04; p = 0.036). The percentage of CD44v9-positive tumors was higher in the earlier stages of disease; however, there was no significant difference in the survival of patients in each stage of disease who had positive or negative CD44v9 expression. CD44v9 was highly expressed in EGFR-mutant tumors, particularly in early-stage lung adenocarcinoma, suggesting that CD44v9 expression may play an important role in EGFR-mutant tumors.

Cancer Stem-Cell Marker CD44v9-Positive Cells Arise From Helicobacter pylori-Infected CAPZA1-Overexpressing Cells.

Background & AimsCD44 variant 9 (CD44v9)-positive cancer stem-like cells strongly contribute to the development and recurrence of gastric cancer. However, the origin of CD44v9-positive cells is uncertain.MethodsCD44v9, β-catenin, and epithelial splicing regulatory protein 1 signals were assessed by real-time reverse-transcription polymerase chain reaction, immunoblot analysis, or immunofluorescence microscopy. Capping actin protein of muscle Z-line α subunit 1 (CAPZA1) expression was assessed by immunoblot analysis or immunohistochemical analysis of Mongolian gerbils' gastric mucosa or human biopsy specimens. Levels of oxidative stress were assessed by measuring malondialdehyde and protein carbonylation. Histone H3 acetylation levels in the CAPZA1 proximal promoter region were measured by using chromatin immunoprecipitation analysis with an antibody against the acetylated histone H3 in human gastric carcinoma cell line (AGS) cells.ResultsCD44v9 is expressed in CAPZA1-overexpressing cells in human gastric cancer tissues. CAPZA1 overexpression enhanced expression of β-catenin, which is a transcription factor for CD44, and epithelial splicing regulatory protein 1, which increases alternative splicing of CD44 to generate CD44v9. CAPZA1-overexpressing cells after cytotoxin-associated gene A accumulation showed CD44v9 expression by inducing nuclear accumulation of β-catenin, concomitant with the enhancement of expression of Sal-like protein 4 and Krüppel-like factor 5, which encode reprogramming factors. Oxidative stress increased the CAPZA1 expression in AGS cells through the enhancement of histone H3 acetylation of CAPZA1 promoter. CAPZA1 expression was increased depending on oxidative stress in H pylori–infected gastric mucosa.ConclusionsCD44v9 expression is evoked from CAPZA1-overexpressing cells after accumulation of cytotoxin-associated gene A. Our findings provide important insights into the mechanisms underlying the development of CD44v9-positive cells.

CD44 Variant 6 Expression and Tumor Budding in the Medullary Invasion Front of Mandibular Gingival Squamous Cell Carcinoma Are Predictive Factors for Cervical Lymph Node Metastasis.

Oral squamous cell carcinoma (OSCC) with invasion into the mandibular medullary space has been reported to be a predictive factor for cervical lymph node metastasis (CLNM). As CLNM has been associated with the stemness of cancer cells, we aimed to evaluate the relationship between clinical characteristics and immunohistochemical findings on the invasion front of the medullary invasive OSCC and CLNM. The medical records of 25 patients with the mandibular medullary invasive OSCC who were performed mandibulectomy and neck dissection in our department from 2010 to 2016 were examined. Serial sections were stained with antibodies against CD44 variant 6 (CD44v6) to examine cancer stemness and to evaluate the number of tumor buds in the medullary invasion front of the mandibular invasive OSCC. Categorical data were analyzed by Fisher's exact test. The expression of CD44v6 and the number of tumor buds between the groups with and without pathological CLNM (CLNM+ and CLNM-, respectively) were analyzed using the Mann-Whitney U test. Of the 25 patients, 11 patients were CLNM+. Of the several measured variables, histologic differentiation of the mandibular invasive OSCC was a significant factor for CLNM+. CD44v6 expression and tumor bud formation in the medullary invasion front of the mandibular invasive OSCC were significantly higher in the CLNM+ group, suggests that both CD44v6 and tumor budding in the medullary invasion front are predictive factors for CLNM.