Inhibiting CD164 expression in colon cancer cell line HCT116 leads to reduced cancer cell proliferation, mobility, and metastasis in vitro and in vivo

Zinc oxide nanoparticle regulates the ferroptosis, proliferation, invasion and steaminess of cervical cancer by miR-506-3p/CD164 signaling

Background

Cancer stem cell (CSC) and ferroptosis play critical roles in cancer development, but the underlying mechanisms remain unclear. Cervical cancer induces a great mortality and an increased incidence globally. Zinc oxide nanoparticle is the nanomaterial that has been applied in industrial products and targets multiple cancer cell types and cancer stem cells. Here, we aimed to explore the effect of ZON on CSC and ferroptosis of cervical cancer.

Methods

In the present study, we identified that the treatment of ZON in vitro inhibited the proliferation of cervical cancer cells.

Results

The ZON stimulated the apoptosis of cervical cancer cells. The tumor growth of cervical cancer cells was attenuated by ZON in the xenograft mouse model in vivo. Meanwhile, ZON represses cell invasion and migration of cervical cancer. Crucially, the sphere formation numbers were repressed by ZON. Meanwhile, the SP ratio of cervical cancer cells was inhibited by ZON. The expression of CSC markers, including Sox-2, Oct3/4, and Nanog, was suppressed by circFoxo3 inhibition. Moreover, the ferroptosis was enhanced by ZON in cervical cancer cells. About the mechanism, we observed that ZON enhanced miR-506-3p expression and CD164 was a target of miR-506-3p, in which ZON inhibited CD164 expression by promoting miR-506-3p in cervical cancer cells. We validated that CD164 reversed miR-506-3p-mediated stemness and ferroptosis in cervical cancer cells. ZON repressed stemness and reduced ferroptosis of cervical cancer cells by targeting CD164. ZON inhibits cell growth of cervical cancer in vivo by targeting CD164.

Conclusions

In brief, we concluded that ZON regulated the ferroptosis, proliferation, invasion, and steaminess of cervical cancer by miR-506-3p/CD164 signaling. Our finding provides new insights into the mechanism by which ZON regulates ferroptosis and steaminess of cervical cancer by a miR-506-3p/CD164 axis.

Nuclear Membrane Protein SUN5 Is Highly Expressed and Promotes Proliferation and Migration in Colorectal Cancer by Regulating the ERK Pathway

SUN5 was first identified as a nuclear envelope protein involved in spermatocyte division. We found that SUN5 was highly expressed in some cancers, but its function and mechanism in cancer development remain unclear. In the present study, we demonstrated that SUN5 was highly expressed in colorectal cancer (CRC) tissues and cells, as indicated by bioinformatics analysis, and SUN5 promoted cell proliferation and migration in vitro. Moreover, the overexpression of SUN5 upregulated phosphorylated ERK1/2 (pERK1/2), whereas the knockdown of SUN5 yielded the opposite results. PD0325901 decreased the level of pERK1/2 to inhibit cell proliferation and migration, which was partially reversed by SUN5 overexpression, indicating that drug resistance existed in patients with high SUN5 expression. The xenograft transplantation experiment showed that SUN5 accelerated tumor formation in vivo. Furthermore, we found that SUN5 regulated the ERK pathway via Nesprin2 mediation and promoted the nuclear translocation of pERK1/2 by interacting with Nup93. Thus, these findings indicated that highly expressed SUN5 promoted CRC proliferation and migration by regulating the ERK pathway, which may contribute to the clinical diagnosis and new treatment strategies for CRC.

miR-219a-5p enhances the radiosensitivity of non-small cell lung cancer cells through targeting CD164

Lung cancer is one of the leading causes of cancer-associated mortality. Non-small cell lung carcinoma (NSCLC) accounts for 70–85% of the total cases of lung cancer. Radioresistance frequently develops in NSCLC in the middle and later stages of radiotherapy. We investigated the role of miR-219a-5p in radioresistance of NSCLC. miR-219a-5p expression in serum and lung tissue of lung cancer patients was lower than that in control. Compared with radiosensitive (RS) NSCLC patients, miR-219a-5p expression was decreased in serum and lung tissue in radioresistant patients. miR-219a-5p expression level was negatively associated with radioresistance in NSCLC cell lines. Up-regulation of miR-219a-5p increased radiosensitivity in radioresistant NSCLC cells in vitro and in vivo. Down-regulation of miR-219a-5p decreased radiosensitivity in radiosensitive A549 and H358 cells. miR-219a-5p could directly bind in the 3′UTR of CD164 and negatively regulated CD164 expression. CD164 expression was higher in radioresistant NSCLC tissues than RS tissues. Up-regulation of CD164 significantly inhibited miR-219a-5p-induced regulation of RS in radioresistant A549 and H358 cells. Down-regulation of CD164 significantly inhibited the effect of anti-miR-219a-5p on radiosensitive A549 and H358 cells. miR-219a-5p or down-regulation of CD164 could increase apoptosis and γ-H2A histone family member X (γ-H2AX) expression in radioresistant cells in vitro and in vivo. Up-regulation of CD164 could inhibit the effect of miR-219a-5p on apoptosis and γ-H2AX expression. Our results indicated that miR-219a-5p could inhibit CD164, promote DNA damage and apoptosis and enhance irradiation-induced cytotoxicity. The data highlight miR-219a-5p/CD164 pathway in the regulation of radiosensitivity in NSCLC and provide novel targets for potential intervention.

LncRNA HOTAIR recruits SNAIL to inhibit the transcription of HNF4α and promote the viability, migration, invasion and EMT of colorectal cancer

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HOTAIR recruited SNAIL and reduced the expression of HNF4α to promote EMT of colorectal cancer.

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Provided potential novel long non-coding RNA-directed early diagnosis and therapy for colorectal cancer.

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Provided further insight into the regulatory mechanism of HOTAIR in colorectal cancer.

Colorectal cancer causes severe burdensome on the health by its high fatality and poor prognosis. Hox transcript antisense intergenic RNA (HOTAIR) was believed closely related with the genesis and development of colorectal cancer, but the regulatory mechanism is still to be investigated. The expression of HOTAIR was analyzed in colorectal cancer using both qRT-PCR and ISH assay. The cell viability, migration, invasion and apoptosis rate were evaluated using MTT, BrdU,Transwell and flow cytometryexperiments. The interaction between HOTAIR and SNAIL was detected using RIP and RNA pull-down. The binding of SNAIL to HNF4α promoter was assessed by ChIP. The cell lines that knock down HOTAIR, SNAIL or overexpress HNF4α were constructed using retroviral vector system. The tumorigenic and metastatic capacity of colorectal cancer cells after knocking down HOTAIR were evaluated based on xenograft assay and liver metastases model. HOTAIR was highly expressed in both tissue and cell lines of colorectal cancer, indicated a regulatory function in colorectal cancer. Knock-down of HOTAIR suppressed cell viability, migration, invasion and epithelial-mesenchymal transition (EMT) of colorectal cancer cells in vitro, and inhibited the growth and metastasis of colorectal tumor in nude mice. We further found that HOTAIR suppressed HNF4α via recruiting SNAIL, and the overexpression of HNF4α inhibited cell viability, migration, invasion and EMT of colorectal cancer cells. We demonstrated that HOTAIR regulates the level of HNF4α via recruiting SNAIL, knocking down HOTAIR repressed the cell viability and metestasis of colorectal cancer cell line in vitro, and suppressed the tomorgenesis and migration/invasion of colorectal cancer in vivo.

RP11‑619L19.2 promotes colon cancer development by regulating the miR‑1271‑5p/CD164 axis

Colon cancer (CC) is one of the leading causes of cancer-related mortality in China and western countries. Several studies have demonstrated that long non-coding RNAs (lncRNAs) play critical roles in cancer development. However, the function of lncRNA RP11-619L19.2 in colon cancer remains unclear. The aim of the present study was to investigate the expression pattern, function and underlying mechanism of action of RP11-619L19.2 in CC development and metastasis. RP11-619L19.2 was found to be highly expressed in CC tissues and cell lines, and it was associated with advanced TNM stage and lymph node metastasis. Furthermore, knockdown of RP11-619L19.2 inhibited CC cell proliferation, migration, invasion and epithelial-to-mesenchymal transition (EMT). It was also observed that RP11-619L19.2 was reciprocally repressed by miR-1271-5p. Of note, miR-1271-5p negatively regulated CD164 expression by directly targeting the 3′-untranslated region of CD164. Overexpression of CD164 reversed the antimetastatic activity of RP11-619L19.2 knockdown in CC cells. Mechanistically, it was demonstrated that lncRNA RP11-619L19.2 played an oncogenic role and promoted CC development and metastasis by regulating the miR-1271-5p/CD164 axis and EMT. In conclusion, the findings of the present study indicated that RP11-619L19.2 regulates CD164 expression and EMT by sponging miR-1271-5p, which may provide novel targets for lncRNA-directed diagnosis and therapy for patients with CC.

Insulin-Like Growth Factor 2 mRNA-Binding Protein 3 Modulates Aggressiveness of Ewing Sarcoma by Regulating the CD164-CXCR4 Axis

Ewing sarcoma (EWS) is the second most common bone and soft tissue-associated malignancy in children and young adults. It is driven by the fusion oncogene EWS/FLI1 and characterized by rapid growth and early metastasis. We have previously discovered that the mRNA binding protein IGF2BP3 constitutes an important biomarker for EWS as high expression of IGF2BP3 in primary tumors predicts poor prognosis of EWS patients. We additionally demonstrated that IGF2BP3 enhances anchorage-independent growth and migration of EWS cells suggesting that IGF2BP3 might work as molecular driver and predictor of EWS progression. The aim of this study was to further define the role of IGF2BP3 in EWS progression. We demonstrated that high IGF2BP3 mRNA expression levels correlated with EWS metastasis and disease progression in well-characterized EWS tumor specimens. EWS tumors with high IGF2BP3 levels were characterized by a specific gene signature enriched in chemokine-mediated signaling pathways. We also discovered that IGF2BP3 regulated the expression of CXCR4 through CD164. Significantly, CD164 and CXCR4 colocalized at the plasma membrane of EWS cells upon CXCL12 stimulation. We further demonstrated that IGF2BP3, CD164, and CXCR4 expression levels correlated in clinical samples and the IGF2BP3/CD164/CXCR4 signaling pathway promoted motility of EWS cells in response to CXCL12 and under hypoxia conditions. The data presented identified CD164 and CXCR4 as novel IGF2BP3 downstream functional effectors indicating that the IGF2BP3/CD164/CXCR4 oncogenic axis may work as critical modulator of EWS aggressiveness. In addition, IGF2BP3, CD164, and CXCR4 expression levels may constitute a novel biomarker panel predictive of EWS progression.

Analysis of TGCA data reveals genetic and epigenetic changes and biological function of MUC family genes in colorectal cancer

Aim: Few studies focused on functions and regulatory networks of MUC family members in colorectal cancer based on comprehensive analysis of online database. Materials & methods: Copy number variation, methylation, pathway analysis and drug influence on MUC expression were analyzed based on The Cancer Genome Atlas and GTEx database. Results: Copy number variation analysis showed MUC heterozygous amplification and heterozygous deletion predominate. Methylation of MUC17, MUC12 and MUC4 were found related to gene expression. Function of MUC family genes mainly affects pathways such as apoptosis, cell cycle, DNA damage and EMT pathways. PLX4720, dabrafenib, gefitinib, afatinib and austocystin D can alter the expression of MUC gene. Conclusion: The genetic and epigenetic changes of MUC are related to the level of MUC expression in colorectal cancer.

Identification of new cancer stem cell markers and signaling pathways in HER‑2‑positive breast cancer by transcriptome sequencing

Human epidermal growth factor receptor (HER)‑2‑positive breast cancer accounts for ~25% of all breast cancer cases, has a high propensity for relapse, metastasis and drug resistance, and is associated with a poor prognosis. Therefore, it is necessary to develop more effective therapeutic targets for the treatment of HER‑2‑positive breast cancer. CD44+/CD24‑/low is currently the most commonly used marker for breast cancer stem cells (CSCs), which are considered the main cause of drug resistance, relapse and metastasis. In the present study, the ratio of CD44+/CD24‑/low cells was almost zero in SK‑BR‑3 cells; however, it was >90% in MDA‑MB‑231 cells, as determined by flow cytometry. Since SK‑BR‑3 and MDA‑MB‑231 cells both exhibit a strong propensity for invasion and migration, it was hypothesized that there may be other markers of CSCs in SK‑BR‑3 cells. Therefore, transcriptome sequencing was performed for SK‑BR‑3 and MDA‑MB‑231 cells. It was observed that several leukocyte differentiation antigens and other CSC markers were significantly more highly expressed in SK‑BR‑3 cells. Furthermore, the expression of aldehyde dehydrogenase (ALDH)1A3, CD164 and epithelial cell adhesion molecule (EpCAM) was higher in SK‑BR‑3 cells compared with in other subtypes of breast cell lines, as determined by reverse transcription‑polymerase chain reaction and western blot analysis. In addition, the expression levels of ALDH1A3, ALDH3B2 and EpCAM were higher in HER‑2‑positive breast cancer compared with in paracancerous tissues and other subtypes of breast cancer, as determined by immunohistochemistry. The expression of β‑catenin in the Wnt signaling pathway was lower in SK‑BR‑3 cells compared with in MDA‑MB‑231 cells, which may be used as a prognostic indicator for breast cancer. These findings may help identify novel CSC markers and therapeutic targets for HER‑2‑positive breast cancer.

CD164 regulates proliferation, progression, and invasion of human glioblastoma cells

Grade IV astrocytoma, also known as glioblastoma multiforme (GBM), is the most common and aggressive intracranial glial tumor. GBM is associated with very poor survival and effective treatments have remained elusive so far. Mounting evidence indicates that CD164 contributes to stemness and tumorigenesis in normal cells and is overexpressed in various tumor types, including glioblastoma. Using tissue microarray immunohistochemistry, we show that there is a significant correlation between CD164 expression and glioma type and grade. Depletion of CD164 expression in human glioblastoma cells with siRNA reduced proliferation, migration, and invasiveness. In parallel, immunoblotting showed that downregulation of CD164 expression decreased Akt activation and modified the expression of autophagy markers by upregulating Beclin-1 and LC3B and downregulating p62. These effects were mimicked by inhibition of Akt with MK2206, which suggests that CD164 induces autophagy via Akt/Beclin-1 signaling. We propose that CD164 may serve as a GBM molecular marker and a potential target in therapeutic strategies aimed to improve outcomes for this devastating brain tumor.

CD164 promotes tumor progression and predicts the poor prognosis of bladder cancer

CD164 was found to play a role in many malignant diseases. But the roles of CD164 in human bladder cancer have not yet been studied. The object of our study was to investigate the functions of CD164 in urothelial bladder carcinoma. The immunohistochemistry (IHC) was performed to evaluate the associations between the expression level of CD164 and clinical‐pathological features of patients, and IHC was used to analyze the relationship between CD164 and CXCR4 in tumor tissues. Real‐time qPCR and Western blot were used to measure the expression of relevant genes. The roles of CD164 in tumor cells and tissues were investigated by in vitro and in vivo experiments. The results of immunohistochemistry found that CD164 was associated with clinical and pathological features of patients. High level of CD164 was related to the distant metastasis and vascular invasion of bladder cancer patients. In vitro, by silencing of CD164, the proliferation, migration, and invasion of tumor cells were inhibited significantly by regulating related proteins such as Ki67, proliferating cell nuclear antigen, matrix metalloproteinases‐2, and matrix metalloproteinases‐9. In vivo, knocking‐down of CD164 could reduce the growth and metastasis of tumors in mice. In addition, a co‐expression was found between CD164 and CXCR4 in tumor tissues. In conclusion, our study demonstrated that CD164 was associated with the poor clinical outcomes of BC patients. Silencing of CD164 could inhibit the progression of tumors in vivo and in vitro, which may become an effective target in the treatment of bladder cancer.

Loss and gain of N-linked glycosylation sequons due to single-nucleotide variation in cancer

Despite availability of sequence site-specific information resulting from years of sequencing and sequence feature curation, there have been few efforts to integrate and annotate this information. In this study, we update the number of human N-linked glycosylation sequons (NLGs), and we investigate cancer-relatedness of glycosylation-impacting somatic nonsynonymous single-nucleotide variation (nsSNV) by mapping human NLGs to cancer variation data and reporting the expected loss or gain of glycosylation sequon. We find 75.8% of all human proteins have at least one NLG for a total of 59,341 unique NLGs (includes predicted and experimentally validated). Only 27.4% of all NLGs are experimentally validated sites on 4,412 glycoproteins. With respect to cancer, 8,895 somatic-only nsSNVs abolish NLGs in 5,204 proteins and 12,939 somatic-only nsSNVs create NLGs in 7,356 proteins in cancer samples. nsSNVs causing loss of 24 NLGs on 23 glycoproteins and nsSNVs creating 41 NLGs on 40 glycoproteins are identified in three or more cancers. Of all identified cancer somatic variants causing potential loss or gain of glycosylation, only 36 have previously known disease associations. Although this work is computational, it builds on existing genomics and glycobiology research to promote identification and rank potential cancer nsSNV biomarkers for experimental validation.

Overexpression of CD164 in oral cavity squamous cell carcinoma predicts a favourable prognosis

The aim of the present study was to investigate the association between cluster of differentiation (CD) 164 expression with clinicopathological parameters and prognosis among patients with oral cavity squamous cell carcinoma (OSCC). The present study retrospectively reviewed 70 patients with OSCC who underwent curative primary surgery. A number of patients subsequently received postoperative chemoradiotherapy although the specimens were not exposed to radiation or chemotherapy prior to anti-CD164 antibody immunohistochemical staining. CD164 overexpression was arbitrarily defined as exhibiting an H-score of ≥120. Univariate and multivariate analyses were performed for sex, age, American Joint Committee on Cancer stage, tumour location, histological grade, surgical margin and H-score. The 5-year overall survival rate was 54.4% and the median follow-up time was 46 months for surviving patients. Univariate analyses revealed that a low overall survival rate was associated with advanced-stage disease (P<0.001), buccogingival tumour location (P=0.038) and a CD164 H-score of <120 (P=0.016). Multivariate Cox's regression analyses revealed that poor overall survival rate was associated with advanced-stage disease (P=0.001) and a CD164 H-score of <120 (P=0.04). CD164 overexpression in OSCC was associated with favourable survival rate. Thus, CD164 expression may be a clinically useful predictor of prognosis in patients with OSCC.

CD164 regulates proliferation and apoptosis by targeting PTEN in human glioma

Cluster of differentiation 164 (CD164), a sialomucin, has been demonstrated to be involved in the regulation of proliferation, apoptosis, adhesion and differentiation in multiple cancers. CD164 is regarded to be a potential promotor of tumor growth. However, the involvement of CD164 in human glioma proliferation and apoptosis remains unknown. The aim of the present study was to investigate the expression and oncogenic function of CD164 in normal human astrocytes (NHA) and glioma cells in vitro and in vivo. The results of the present study demonstrated that CD164 mRNA and protein levels were significantly increased in human glioma cell lines and tissue samples. CD164 overexpression promoted the proliferation of NHA in vitro, and its tumorigenic effect was confirmed in a murine xenograft model. Knockdown of CD164 inhibited cell proliferation and promoted apoptosis of the U87 human glioma cell line in vitro and in vivo. In addition, knockdown of CD164 was demonstrated to upregulate the Bax/Bcl2 ratio and phosphatase and tensin homolog (PTEN) expression, reduce protein kinase B (AKT) phosphorylation and promote the expression of p53 in U87 cells. The results suggest that CD164 expression may have affected the proliferation and apoptosis of human glioma cells via the PTEN/phosphoinositide 3-kinase/AKT pathway, and may therefore present a potential target for the diagnosis and treatment of glioma.

CD164 identifies CD4+ T cells highly expressing genes associated with malignancy in Sézary syndrome: the Sézary signature genes, FCRL3, Tox, and miR-214

Sézary syndrome (SS), a leukemic variant of cutaneous T-cell lymphoma (CTCL), is associated with a significantly shorter life expectancy compared to skin-restricted mycosis fungoides. Early diagnosis of SS is, therefore, key to achieving enhanced therapeutic responses. However, the lack of a biomarker(s) highly specific for malignant CD4+ T cells in SS patients has been a serious obstacle in making an early diagnosis. We recently demonstrated the high expression of CD164 on CD4+ T cells from Sézary syndrome patients with a wide range of circulating tumor burdens. To further characterize CD164 as a potential biomarker for malignant CD4+ T cells, CD164+ and CD164-CD4+ T cells isolated from patients with high-circulating tumor burden, B2 stage, and medium/low tumor burden, B1-B0 stage, were assessed for the expression of genes reported to differentiate SS from normal controls, and associated with malignancy and poor prognosis. The expression of Sézary signature genes: T plastin, GATA-3, along with FCRL3, Tox, and miR-214, was significantly higher, whereas STAT-4 was lower, in CD164+ compared with CD164-CD4+ T cells. While Tox was highly expressed in both B2 and B1-B0 patients, the expression of Sézary signature genes, FCRL3, and miR-214 was associated predominantly with advanced B2 disease. High expression of CD164 mRNA and protein was also detected in skin from CTCL patients. CD164 was co-expressed with KIR3DL2 on circulating CD4+ T cells from high tumor burden SS patients, further providing strong support for CD164 as a disease relevant surface biomarker.

Anti-cancer activities of Brassica juncea leaves in vitro

Mustard (Brassica juncea) leaves are commonly consumed in different Asian and African countries. Cancer is a major burden of disease worldwide, and the colorectal and lung cancers are the leading cause of morbidity and mortality among cancers. In the current study, we aimed to investigate the effects of ethanol extract of mustard leaf (MLE) on the growth, angiogenic, and metastatic potentials of HCT116 colorectal carcinoma and H1299 non-small cell lung carcinoma cells in vitro. Treatment of HCT116 and H1299 cells with MLE inhibited cell growth in a dose-dependent manner (in the range of 175-700 µg/ml, by 39-86 %) and anchorage-independent colonization (at 700 µg/ml, by 56-86 %). Induction of apoptosis by MLE was evidenced by heterogeneous and condensed nucleus morphology, increased 4′,6-diamidino-2-phenylindole dihydrochloride staining intensity, and elevated sub-G1 cell population. In both HCT116 and H1299 cells, treatment with MLE markedly suppressed the secretion of key pro-angiogenic factors, such as vascular endothelial cell growth factor (by >92 %) and basic fibroblast growth factor (by 73-94 %). MLE was also effective in inhibiting critical events during metastasis, such as invasion (by 18-33 % in HCT116 and H1299), migration (45-82 % in H1299), and adhesion (by 17-45 % in HCT116 and H1299). These results indicate that MLE possesses in vitro anti-cancer activities against colon and lung cancers. It needs to be verified whether similar effects are reproduced in vivo.

Identification and Characterization of CD107a as a Marker of Low Reactive Oxygen Species in Chemoresistant Cells in Colorectal Cancer

BACKGROUND

Reactive oxygen species (ROS) generated by chemoradiotherapy lead to cancer cell death. Although ROS regulation mechanisms play important roles in chemoradioresistance, few markers exist that indicated intracellular ROS status. This study aimed to identify novel cell surface markers that represented intracellular ROS status to characterize cells with low ROS (ROS^low) in colorectal cancer (CRC).

METHODS

We used ROS indicators and an antibody array with 242 cell surface antibodies to identify markers of ROS^low cells. After validation, we performed immunohistochemical analyses and chemosensitivity assays. We used small interfering RNA to assess the effect of silencing the identified markers. We tested cell differentiation assays with spheroid cell assays.

RESULTS

CD107a was identified as a common marker of ROS^low cells in several CRC cell lines and clinical specimens. CD107a⁺/ROS^low cells were enriched in HT29 and DLD1 cultures after treatments with oxaliplatin, 5-fluorouracil, and the irinotecan metabolite SN38. CD107a silencing improved chemosensitivity by increasing ROS production. Immunohistochemistry showed enhanced CD107a surface expression on cells that formed immature cell clusters and on cells located in the invasive fronts of cancer foci. CD107a expression was also enhanced on specimens from patients with poorly differentiated adenocarcinoma who had received neoadjuvant chemotherapy. Cell surface CD107a expression was enhanced on cells that formed colonospheres, but expression diminished during cell differentiation.

CONCLUSIONS

CD107a was identified as a novel marker of ROS^low cells in CRC. CD107a expression was closely related to chemoresistance and the immature cell phenotype. Anti-CD107a treatments represent a novel approach for targeting chemoresistant cells in CRC.

CD164 promotes lung tumor-initiating cells with stem cell activity and determines tumor growth and drug resistance via Akt/mTOR signaling

CD164 is a cell adhesion molecule that increases hematopoietic stem cell proliferation, adhesion, and migration via C-X-C chemokine receptor type 4 (CXCR4) signaling. Emerging evidence indicates that elevated CD164 expression is associated with aggressive metastasis, advanced stages, and shorter overall survival in lung cancer. However, no data are available regarding the clinical significance of CD164 expression in lung cancer. This study explores whether CD164 promotes tumor-initiation and drug resistance through the stem cell property. Using tissue microarrays, we determine that CD164 expression is correlated with clinicopathological characteristics in human lung cancer. The CD164 overexpression in normal lung epithelial cells (BEAS2B cells) leads to malignant transformation in vitro, tumorigenicity in xenografted mice, stem cell-like property, and drug resistance through ATP-binding cassette transporters. The CD164 overexpression increases CXCR4 expression and activates Akt/mTOR signaling. Rapamycin, an mTOR inhibitor, hinders cell proliferation along with sphere formation in vitro and impedes tumor growth in vivo. In conclusion, we have provided evidence that CD164 promotes the growth of lung tumor-initiating cells with stem cell properties and induces tumor growth and drug resistance through Akt/mTOR signaling. Therefore, identification of CD164 as a cancer stem cell therapeutic marker may develop an effective therapy in patients with chemoresistant lung cancer.

Hyaluronan-conjugated liposomes encapsulating gemcitabine for breast cancer stem cells

Investigation of potential therapeutics for targeting breast cancer stem cells (BCSCs) is important because these cells are regarded as culprit of breast cancer relapse. Accomplishing this kind of strategy requires a specific drug-delivery system using the distinct features of liposomes. Studies on targeted liposomal delivery systems have indicated the conjugation of hyaluronan (HA), a primary ligand for CD44 surface markers, as an appropriate method for targeting BCSCs. For this study, enriched BCSCs were obtained by culturing MCF-7 breast cancer cells in nonadherent conditions. The enriched BCSCs were challenged with HA-conjugated liposomes encapsulating gemcitabine (2, 2-difluoro-2-deoxycytidine, GEM). In vitro study showed that the HA-conjugated liposomes significantly enhanced the cytotoxicity, anti-migration, and anti-colony formation abilities of GEM through targeting of CD44 expressed on BCSCs. In pharmacokinetic study, area under the drug concentration vs time curve (AUC) of the immunoliposomal GEM was 3.5 times higher than that of free GEM, indicating that the HA-conjugated liposomes enhanced the stability of GEM in the bloodstream and therefore prolonged its half-life time. The antitumor effect of the immunoliposomal GEM was 3.3 times higher than that of free GEM in a xenograft mouse model, probably reflecting the unique targeting of the CD44 receptor by HA and the increased cytotoxicity and stability through the liposomal formulation. Furthermore, marginal change in body weight demonstrated that the use of liposomes considerably reduced the systemic toxicity of GEM on normal healthy cells. Taken together, this study demonstrates that HA-conjugated liposomes encapsulating GEM show promise for the therapy of breast cancer in vitro and in a xenograft model by targeting the BCSCs.

The role of novel and known extracellular matrix and adhesion molecules in the homeostatic and regenerative bone marrow microenvironment

Maintenance of haematopoietic stem cells and differentiation of committed progenitors occurs in highly specialized niches. The interactions of haematopoietic stem and progenitor cells (HSPCs) with cells, growth factors and extracellular matrix (ECM) components of the bone marrow (BM) microenvironment control homeostasis of HSPCs. We only start to understand the complexity of the haematopoietic niche(s) that comprises endosteal, arterial, sinusoidal, mesenchymal and neuronal components. These distinct niches produce a broad range of soluble factors and adhesion molecules that modulate HSPC fate during normal hematopoiesis and BM regeneration. Adhesive interactions between HSPCs and the microenvironment will influence their localization and differentiation potential. In this review we highlight the current understanding of the functional role of ECM- and adhesion (regulating) molecules in the haematopoietic niche during homeostatic and regenerative hematopoiesis. This knowledge may lead to the improvement of current cellular therapies and more efficient development of future cellular products.

Inhibitory activities of Perilla frutescens britton leaf extract against the growth, migration, and adhesion of human cancer cells

BACKGROUND/OBJECTIVES

Perilla frutescens Britton leaves are a commonly consumed vegetable in different Asian countries including Korea. Cancer is a major cause of human death worldwide. The aim of the current study was to investigate the inhibitory effects of ethanol extract of perilla leaf (PLE) against important characteristics of cancer cells, including unrestricted growth, resisted apoptosis, and activated metastasis, using human cancer cells.

MATERIALS/METHODS

Two human cancer cell lines were used in this study, HCT116 colorectal carcinoma cells and H1299 non-small cell lung carcinoma cells. Assays using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide were performed for measurement of cell growth. Soft agar and wound healing assays were performed to determine colony formation and cell migration, respectively. Nuclear staining and cell cycle analysis were performed for assessment of apoptosis. Fibronectin-coated plates were used to determine cell adhesion.

RESULTS

Treatment of HCT116 and H1299 cells with PLE resulted in dose-dependent inhibition of growth by 52-92% (at the concentrations of 87.5, 175, and 350 µg/ml) and completely abolished the colony formation in soft agar (at the concentration of 350 µg/ml). Treatment with PLE at the 350 µg/ml concentration resulted in change of the nucleus morphology and significantly increased sub-G1 cell population in both cells, indicating its apoptosis-inducing activity. PLE at the concentration range of 87.5 to 350 µg/ml was also effective in inhibiting the migration of H1299 cells (by 52-58%) and adhesion of both HCT116 and H1299 cells (by 25-46%).

CONCLUSIONS

These results indicate that PLE exerts anti-cancer activities against colon and lung cancers in vitro. Further studies are needed in order to determine whether similar effects are reproduced in vivo.

Interfering with CXCR4 expression inhibits proliferation, adhesion and migration of breast cancer MDA-MB-231 cells

To investigate the effect and mechanism of the CXC chemokine receptor 4 (CXCR4) in the proliferation and migration of breast cancer, a short-hairpin RNA (shRNA) eukaryotic expression vector targeting CXCR4 was constructed, and the impact of such on the proliferation, adhesion and migration of human breast cancer MDA-MB-231 cells was observed. The fragments of CXCR4-shRNA were synthesized and cloned into a pGCsi-U6-Neo-green fluorescent protein vector. The recombinant plasmids were transfected into 293T cells and the most efficacious interfering vector was selected. MDA-MB-231 cells were transfected by liposome assay. The effects of silencing CXCR4 expression by shRNA on the growth, adhesion and migration of MDA-MB-231 cells were determined by Cell Counting Kit-8, cell-matrix adhesion and wound-healing assays. The shRNA eukaryotic expression vectors targeting CXCR4 (CXCR4-shRNA) were successfully constructed and transfected into 293T cells. Quantitative polymerase chain reaction and western blot analysis revealed that the maximum inhibitory rate of CXCR4 expression was 81.3%. CXCR4-shRNA transfection significantly inhibited the proliferation of MDA-MB-231 cells (P<0.05), as well as the adhesion between MDA-MB-231 cells and the extracellular matrix (P<0.05). Furthermore, wound-healing assays demonstrated that the migration distance of MDA-MB-231 cells in the CXCR4-shRNA transfection group was significantly smaller than that in the control plasmid and blank control groups (P<0.01). The CXCR4-shRNA interfering vector specifically inhibited CXCR4 expression, as well as the proliferation, adhesion and migration of MDA-MB-231 cells.

miR-219 inhibits the proliferation, migration and invasion of medulloblastoma cells by targeting CD164

It is known that microRNA-219 (miR-219) expression is downregulated in medulloblastoma. In the present study, we investigated the expression, targets and functional effects of miR-219 in D283-MED medulloblastoma cells. We first demonstrated that miR-219 not only inhibits proliferation, but also suppresses the invasion and migration of D283-MED cells. Moreover, the knockdown of miR-219 promoted the proliferation, migration and invasion of the D283-MED cells. Secondly, we predicted that miR-219 targets the 3' untranslated region (3'UTR) of CD164 and orthodenticle homeobox 2 (OTX2) and then confirmed that it significantly downregulated the protein expression of CD164 and OTX2 in D283-MED cells. Finally, we demonstrated that the proliferation, invasion and migration of D283-MED cells were promoted by theectopic expression of CD164. These results indicate that miR-219 suppresses the proliferation, migration and invasion of medulloblastoma cells by targeting CD164. The results also suggest that miR-219 may serve as a potential therapeutic agent for medulloblastoma.

Should EMT of Cancer Cells Be Understood as Epithelial-Myeloid Transition?

Cancer cells express epithelial markers, and when progressing in malignancy they may express markers of the mesenchymal cell type. Therefore an epithelial-mesenchymal transition of the cancer cells is assumed. However the mesenchymal markers can equally well be interpreted as myeloid markers since they are common in both types of cell lineages. Moreover, cancer cells express multiple specific markers of the myeloid lineages thus giving rise to the hypothesis that the transition of cancer cells may be from epithelial to myeloid cells and not to mesenchymal cells. This interpretation would better explain why cancer cells, often already in their primary cancer site, frequently show properties common to those of macrophages, platelets and pre-/osteoclasts.

CD164 regulates the tumorigenesis of ovarian surface epithelial cells through the SDF-1α/CXCR4 axis

Background

CD164 (endolyn), a sialomucin, has been reported to play a role in the proliferation, adhesion, and differentiation of hematopoietic stem cells. The potential association of CD164 with tumorigenicity remains unclear.

Methods

The clinicopathological correlation of ovarian cancer with CD164 was assessed in a 97-patient tumor tissue microarray. Overexpression or silence CD164 was to analyze the effect of CD164 on the proliferation, colony formation and apoptosis via a mouse xenograft and western blotting analysis. The subcellular localization of CD164 was collected in the immunohistochemical and confocal analysis.

Results

Our data demonstrated that higher expression levels of CD164 were identified in malignant ovarian cancer cell lines, such as SKOV3 and HeyA8. The clinicopathological correlation analysis showed that the upregulation of CD164 protein was significantly associated with tumor grade and metastasis. The overexpression of CD164 in human ovarian epithelial surface cells promoted cellular proliferation and colony formation and suppressed apoptosis. These tumorigenicity effects of CD164 were reconfirmed in a mouse xenograft model. We also found that the overexpression of CD164 proteins increased the amounts of CXCR4 and SDF-1α and activated the SDF-1α/CXCR4 axis, inducing colony and sphere formation. Finally, we identified the subcellular localization of CD164 in the nucleus and cytosol and found that nuclear CD164 might be involved in the regulation of the activity of the CXCR4 promoter.

Conclusions

Our findings suggest that the increased expression of CD164 is involved in ovarian cancer progression via the SDF-1α/CXCR4 axis, which promotes tumorigenicity. Thus, targeting CD164 may serve as a potential ovarian cancer biomarker, and targeting CD164 may serve as a therapeutic modality in the management of high-grade ovarian tumors.

The key regulatory roles of the PI3K/Akt signaling pathway in the functionalities of mesenchymal stem cells and applications in tissue regeneration

Mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into various cell types and have been widely used in tissue engineering application. In tissue engineering, a scaffold, MSCs and growth factors are used as essential components and their interactions have been regarded to be important for regeneration of tissues. A critical problem for MSCs in tissue engineering is their low survival ability and functionality. Most MSCs are going to be apoptotic after transplantation. Therefore, increasing MSC survival ability and functionalities is the key for potential applications of MSCs. Several approaches have been studied to increase MSC tissue forming capacity including application of growth factors, overexpression of stem cell regulatory genes, and improvement of biomaterials for scaffolds. The effects of these approaches on MSCs have been associated with activation of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. The pathway plays central regulatory roles in MSC survival, proliferation, migration, angiogenesis, cytokine production, and differentiation. In this review, we summarize and discuss the literatures related to the roles of the PI3K/Akt pathway in the functionalities of MSCs and the involvement of the pathway in biomaterials-increased MSC functionalities. Biomaterials have been modified in their properties and surface structure and loaded with growth factors to increase MSC functionalities. Several studies demonstrated that the biomaterials-increased MSC functionalities are mediated by the activation of the PI3K/Akt pathway.

Apical targeting and endocytosis of the sialomucin endolyn are essential for establishment of zebrafish pronephric kidney function

Kidney function requires the appropriate distribution of membrane proteins between the apical and basolateral surfaces along the kidney tubule. Further, the absolute amount of a protein at the cell surface versus intracellular compartments must be attuned to specific physiological needs. Endolyn (CD164) is a transmembrane protein that is expressed at the brush border and in apical endosomes of the proximal convoluted tubule and in lysosomes of more distal segments of the kidney. Endolyn has been shown to regulate CXCR4 signaling in hematopoietic precursor cells and myoblasts; however, little is known about endolyn function in the adult or developing kidney. Here we identify endolyn as a gene important for zebrafish pronephric kidney function. Zebrafish endolyn lacks the N-terminal mucin-like domain of the mammalian protein, but is otherwise highly conserved. Using in situ hybridization we show that endolyn is expressed early during development in zebrafish brain, eye, gut and pronephric kidney. Embryos injected with a translation-inhibiting morpholino oligonucleotide targeted against endolyn developed pericardial edema, hydrocephaly and body curvature. The pronephric kidney appeared normal morphologically, but clearance of fluorescent dextran injected into the common cardinal vein was delayed, consistent with a defect in the regulation of water balance in morphant embryos. Heterologous expression of rat endolyn rescued the morphant phenotypes. Interestingly, rescue experiments using mutant rat endolyn constructs revealed that both apical sorting and endocytic/lysosomal targeting motifs are required for normal pronephric kidney function. This suggests that both polarized targeting and postendocytic trafficking of endolyn are essential for the protein's proper function in mammalian kidney.