Olfactomedin 4 suppresses tumor growth and metastasis of mouse melanoma cells through downregulation of integrin and MMP genes

HIFU-CCL19/21 Axis Enhances Dendritic Cell Vaccine Efficacy in the Tumor Microenvironment

BACKGROUND/OBJECTIVES

Effectively targeting treatment-resistant tumor cells, particularly cancer stem cells (CSCs) involved in tumor recurrence, remains a major challenge in immunotherapy. This study examines the potential of combining mechanical high-intensity focused ultrasound (M-HIFU) with dendritic cell (DC) vaccines to enhance immune responses against OLFM4-expressing tumors, a CSC marker linked to immune evasion and tumor growth.

METHODS

M-HIFU was applied to induce immunogenic cell death by mechanically disrupting tumor cells, releasing tumor-associated antigens and creating an immunostimulatory environment. DC vaccines loaded with OLFM4 were then administered to boost the immune response within this primed environment.

RESULTS

The combination of M-HIFU and DC vaccine significantly inhibited tumor growth and metastasis, with enhanced T-cell activation and increased recruitment of immune cells due to elevated chemokines CCL19 and CCL21. This synergy promoted immune memory, reducing the likelihood of recurrence.

CONCLUSIONS

M-HIFU effectively promotes the migration of DC vaccines through CCL19/21, presenting a promising approach for cancer treatment. Further studies are recommended to optimize this combination for clinical applications, with potential to improve patient outcomes in challenging cancer types.

An Integrative Transcriptomic Analysis of Systemic Juvenile Idiopathic Arthritis for Identifying Potential Genetic Markers and Drug Candidates

Systemic juvenile idiopathic arthritis (sJIA) is a rare subtype of juvenile idiopathic arthritis, whose clinical features are systemic fever and rash accompanied by painful joints and inflammation. Even though sJIA has been reported to be an autoinflammatory disorder, its exact pathogenesis remains unclear. In this study, we integrated a meta-analysis with a weighted gene co-expression network analysis (WGCNA) using 5 microarray datasets and an RNA sequencing dataset to understand the interconnection of susceptibility genes for sJIA. Using the integrative analysis, we identified a robust sJIA signature that consisted of 2 co-expressed gene sets comprising 103 up-regulated genes and 25 down-regulated genes in sJIA patients compared with healthy controls. Among the 128 sJIA signature genes, we identified an up-regulated cluster of 11 genes and a down-regulated cluster of 4 genes, which may play key roles in the pathogenesis of sJIA. We then detected 10 bioactive molecules targeting the significant gene clusters as potential novel drug candidates for sJIA using an in silico drug repositioning analysis. These findings suggest that the gene clusters may be potential genetic markers of sJIA and 10 drug candidates can contribute to the development of new therapeutic options for sJIA.

Identification of metastasis-related genes by genomic and transcriptomic studies in murine melanoma

AIMS

We systematically characterized metastatic murine B16-F10 melanoma, a sub-line derived from murine melanoma B16-F1 cells.

MATERIALS AND METHODS

RNA-sequencing and network analyses (Ingenuity Pathway Analysis) were performed to identify novel potential metastasis mechanisms. Chromosomal aberrations were identified by multicolor fluorescence in situ hybridization (mFISH) using all 21 murine whole chromosome painting probes.

KEY FINDINGS

Numerous genes were overexpressed in B16-F10 cells, some of which have been already described as being metastasis-linked. Nr5a1/sf1, a known prognostic marker for adrenal tumors, was 177-fold upregulated in B16-F10 cells compared to B16-F1 cells. Hoxb8 was 75-fold upregulated, which was previously associated with gastric cancer progression and metastasis. Ptk7, which is linked with tumorigenesis and metastasis of esophageal squamous carcinoma, was 67-fold upregulated. B16-F10 cells acquired additional chromosomal aberrations compared to B16-F1 cells, including dic(4)(pter->qter:qter->pter), +dic(6;15), +der(10)t(10;?1;16).

SIGNIFICANCE

In addition to well-known metastatic genes, numerous novel genes and genomic aberrations were identified, which may serve as targets for treatment in the future. Transcriptomic and genetic analyses in B16-F10 cells unraveled a range of novel metastasis mechanisms, which may also have important implications for future treatment strategies.

The Combination of Sulforaphane and Fernblock® XP Improves Individual Beneficial Effects in Normal and Neoplastic Human Skin Cell Lines

Plenty of evidence supports the health effects exerted by dietary supplements containing phytochemicals, but the actual efficacy and safety of their combinations have been seldom experimentally evaluated. On this basis, we investigated in vitro the antioxidant/antineoplastic efficacy and anti-aging activity of a dietary supplement containing sulforaphane (SFN), a sulfur-isothiocyanate present in broccoli, combined with the patented extract Fernblock^® XP (FB), obtained from the tropical fern Polypodium leucotomos. We evaluated the effect of SFN and FB, alone or in combination, on migration ability, matrix metalloproteinases (MMP) production, neoangiogenic potential and inflammasome activation in human WM115 and WM266-4 melanoma cells. Moreover, the effects on MMPs and reactive oxygen species production, and IL-1β secretion were studied in human normal keratinocytes. The SFN/FB combination inhibited melanoma cell migration in vitro, MMP-1, -2, -3, and -9 production, inflammasome activation and IL-1β secretion more efficiently than each individual compound did. In normal keratinocytes, SFN/FB was more efficient than SFN or FB alone in inhibiting MMP-1 and -3 production and IL-1β secretion in the presence of a pro-inflammatory stimulus such as TNF-α. The potential use of SFN/FB based supplements for the prevention of skin aging and as adjuvants in the treatment of advanced melanoma is suggested.

Blocking OLFM4/HIF-1α axis alleviates hypoxia-induced invasion, epithelial-mesenchymal transition, and chemotherapy resistance in non-small-cell lung cancer

Hypoxia is a common biological hallmark of solid cancers, which has been proposed to be associated with oncogenesis and chemotherapy resistance. The purpose of the present study was to investigate the role and underlying mechanisms of olfactomedin 4 (OLFM4) in the hypoxia-induced invasion, epithelial-mesenchymal transition (EMT), and chemotherapy resistance of non-small-cell lung cancer (NSCLC). We observed dramatically upregulated expression of OLFM4 in several NSCLC cell lines, and this effect was more pronounced in A549 and H1299 cells. In addition, our data revealed that OLFM4 expression was remarkably increased in both A549 and H1299 cells under hypoxic microenvironment, accompanied by enhanced levels of hypoxia-inducible factor (HIF)-1α protein. The HIF-1α level was elevated in response to hypoxia, resulting in the regulation of OLFM4. Interestingly, OLFM4 was a positive regulator of hypoxia-driven HIF-1α production. Moreover, depletion of OLFM4 modulated multiple EMT-associated proteins, as evidenced by the enhanced E-cadherin levels along with the diminished expression of N-cadherin and vimentin in response to hypoxia, and thus blocked invasion ability of A549 and H1299 cells following exposure to hypoxia. Furthermore, ablation of OLFM4 accelerated the sensitivity of A549 cells to cisplatin under hypoxic conditions, implying that OLFM4 serves as a key regulator in chemotherapeutic resistance under hypoxia. In conclusion, OLFM4/HIF-1α axis might be a potential therapeutic strategy for NSCLC.

Olfactomedin 4 downregulation is associated with tumor initiation, growth and progression in human prostate cancer

The olfactomedin 4 (OLFM4) gene has been analyzed as a tumor‐suppressor gene and a putative biomarker in many cancers. In our study, we analyzed the relationship of OLFM4 expression with clinicopathological features and with CpG site methylation in the OLFM4 gene promoter region in human primary prostate adenocarcinoma. OLFM4 protein expression was significantly reduced in prostate cancer tissue compared to adjacent normal tissue and was further significantly reduced in more advanced cancers. Bioinformatic studies with clinical datasets revealed that primary prostate adenocarcinoma patients with reduced OLFM4 mRNA expression exhibited higher Gleason scores and higher preoperative serum prostate‐specific antigen levels, as well as lower recurrence‐free survival. Three of the eight CpG sites in the OLFM4 gene promoter region were hypermethylated in cancerous prostate cells compared to adjacent normal cells, and reduced methylation of eight CpG sites was associated with increased OLFM4 mRNA expression in RWPE1 and PC‐3 cells. Furthermore, knockdown of OLFM4 gene expression was associated with enhanced epithelial–mesenchymal transition (EMT)‐marker expression in RWPE immortalized normal prostate cells. In contrast, restoration of OLFM4 expression in PC‐3 and DU145 prostate cancer cells lacking OLFM4 significantly inhibited both EMT‐marker expression and tumor cell growth in in vitro and in vivo models, indicating that OLFM4 may play a tumor‐suppressor role in inhibiting the EMT program, as well as tumor initiation and growth, in prostate cells. Taken together, these findings suggest that OLFM4 plays an important tumor‐suppressor role in prostate cancer progression and might be useful as a novel candidate biomarker for prostate cancer.

What's new?

Altered expression of the OLFM4 gene appears to be involved in many cancers. In this study of prostate cancers, the authors found that OLFM4 can suppress tumor initiation, growth and progression. Downregulation of OLFM4 was associated with higher serum PSA levels, higher Gleason scores, and lower recurrence‐free survival in prostate cancer patients. These results indicate that OLFM4 may play an important tumor‐suppressor role in the progression of prostate cancer, and may provide a novel prognostic biomarker for prostate cancer treatment.

Plasma olfactomedin 4 level in peripheral blood and its association with clinical features of breast cancer

The present study aimed to investigate the expression of olfactomedin 4 (OLFM4) in plasma of patients with breast cancer and its association with diagnosis, metastasis and prognosis of breast cancer. OLFM4 gene expression level of peripheral blood plasma in 60 patients with breast cancer and 26 healthy donors was examined by ELISA. The expression of OLFM4 in tumor tissues of patients with breast cancer was evaluated by immunohistochemistry (protein expression) and reverse transcription-quantitative polymerase chain reaction (mRNA expression), respectively. Circulating tumor cells (CTCs) were detected in a certain set of patients. The expression of OLFM4 in plasma of the overall healthy people was higher compared with patients with breast cancer. The plasma OLFM4 level in patients with breast cancer was consistent with the expression of OLFM4 protein in tumor tissues (R²=1), indicating that the level of plasma OLFM4 expression may represent the expression of OLFM4 in breast cancer tissues. The plasma OLFM4 level in patients with histological grade I was significantly lower compared with grade III (P<0.05). Breast cancer patients with positive CTC were associated with low level of plasma OLFM4. These results suggest that low OLFM4 expression in plasma or tissue specimens of breast cancer patients is more likely to represent low histological differentiation and decreased invasive/metastatic capabilities. Taken together, plasma OLFM4 level may be considered as a biomarker for diagnosis and prognosis of breast cancer for cases where there are difficulties in obtaining tumor tissue samples.

The clinical significance and biological function of olfactomedin 4 in triple negative breast cancer

Olfactomedin 4 abnormal expression has been observed in several types of human cancer, but the status of olfactomedin 4 in triple negative breast cancer is still unknown. The aim of our study is to explore the clinical significance and biological function of olfactomedin 4 in triple negative breast cancer. The mRNA and protein expression of olfactomedin 4 in triple negative breast cancer tissues and cell lines was detected, and the correlation between olfactomedin 4 expression and clinicopathological factors was analyzed by immunohistochemistry. The biological function of olfactomedin 4 on tumor-metastasis was explored by Transwell migration assay and invasion assay in vitro. In our results, olfactomedin 4 mRNA and protein expression is decreased in triple-negative breast cancer tissues and cell lines. Olfactomedin 4 protein low-expression associated with lymph node metastasis, distant metastasis, clinical stage and poor prognosis of triple-negative breast cancer patients. Up-regulation of olfactomedin 4 suppresseed triple-negative breast cancer cells migration and invasion, and reduced cell metastasis-associated protein MMP 9 expression. In conclusion, olfactomedin 4 is a novel biomarker of triple-negative breast cancer for predicting prognosis and developing targeted molecular therapies.

GRIM-19: A master regulator of cytokine induced tumor suppression, metastasis and energy metabolism

Cytokines induce cell proliferation or growth suppression depending on the context. It is increasingly becoming clear that success of standard radiotherapy and/or chemotherapeutics to eradicate solid tumors is dependent on IFN signaling. In this review we discuss the molecular mechanisms of tumor growth suppression by a gene product isolated in our laboratory using a genome-wide expression knock-down strategy. Gene associated with retinoid-IFN-induced mortality -19 (GRIM-19) functions as non-canonical tumor suppressor by antagonizing oncoproteins. As a component of mitochondrial respiratory chain, GRIM-19 influences the degree of "Warburg effect" in cancer cells as many advanced and/or aggressive tumors show severely down-regulated GRIM-19 levels. In addition, GRIM-19 appears to regulate innate and acquired immune responses in mouse models. Thus, GRIM-19 is positioned at nodes that favor cell protection and/or prevent aberrant cell growth.

Epigenetic silencing of olfactomedin-4 enhances gastric cancer cell invasion via activation of focal adhesion kinase signaling

Downregulation of olfactomedin-4 (OLFM4) is associated with tumor progression, lymph node invasion and metastases. However, whether or not downregulation of OLFM4 is associated with epigenetic silencing remains unknown. In this study, we investigate the role of OLFM4 in gastric cancer cell invasion. We confirm the previous result that OLFM4 expression is increased in gastric cancer tissues and decreases with an increasing number of metastatic lymph nodes, which are associated with OLFM4 promoter hypermethylation. Overexpression of OLFM4 in gastric cancer cells had an inhibitory effect on cell invasion. Furthermore, we found that focal adhesion kinase (FAK) was negatively correlated with OLFM4 in regards to lymph node metastasis in gastric cancer tissues. Also, inhibition of FAK induced by OLFM4 knockdown resulted in a decrease in cell invasion. Thus, our study demonstrates that epigenetic silencing of OLFM4 enhances gastric cancer cell invasion via activation of FAK signaling. [BMB Reports 2015; 48(11): 630-635]

The Response of microRNAs to Solar UVR in Skin-Resident Melanocytes Differs between Melanoma Patients and Healthy Persons

The conversion of melanocytes into cutaneous melanoma is largely dictated by the effects of solar ultraviolet radiation (UVR). Yet to be described, however, is exactly how these cells are affected by intense solar UVR while residing in their natural microenvironment, and whether their response differs in persons with a history of melanoma when compared to that of healthy individuals. By using laser capture microdissection (LCM) to isolate a pure population of melanocytes from a small area of skin that had been intermittingly exposed or un-exposed to physiological doses of solar UVR, we can now report for the first time that the majority of UV-responsive microRNAs (miRNAs) in the melanocytes of a group of women with a history of melanoma are down-regulated when compared to those in the melanocytes of healthy controls. Among the miRNAs that were commonly and significantly down-regulated in each of these women were miR-193b (P<0.003), miR-342-3p (P<0.003), miR186 (P<0.007), miR-130a (P<0.007), and miR-146a (P<0.007). To identify genes potentially released from inhibition by these repressed UV-miRNAs, we analyzed databases (e.g., DIANA-TarBase) containing experimentally validated microRNA-gene interactions. In the end, this enabled us to construct UV-miRNA-gene regulatory networks consisting of individual genes with a probable gain-of-function being intersected not by one, but by several down-regulated UV-miRNAs. Most striking, however, was that these networks typified well-known regulatory modules involved in controlling the epithelial-to-mesenchymal transition and processes associated with the regulation of immune-evasion. We speculate that these pathways become activated by UVR resulting in miRNA down regulation only in melanocytes susceptible to melanoma, and that these changes could be partially responsible for empowering these cells toward tumor progression.

Discovery of survival factor for primitive chronic myeloid leukemia cells using induced pluripotent stem cells

A definitive cure for chronic myeloid leukemia (CML) requires identifying novel therapeutic targets to eradicate leukemia stem cells (LSCs). However, the rarity of LSCs within the primitive hematopoietic cell compartment remains a major limiting factor for their study in humans. Here we show that primitive hematopoietic cells with typical LSC features, including adhesion defect, increased long-term survival and proliferation, and innate resistance to tyrosine kinase inhibitor (TKI) imatinib, can be generated de novo from reprogrammed primary CML cells. Using CML iPSC-derived primitive leukemia cells, we discovered olfactomedin 4 (OLFM4) as a novel factor that contributes to survival and growth of somatic lin(-)CD34(+) cells from bone marrow of patients with CML in chronic phase, but not primitive hematopoietic cells from normal bone marrow. Overall, this study shows the feasibility and advantages of using reprogramming technology to develop strategies for targeting primitive leukemia cells.

Plasma levels of OLFM4 in normals and patients with gastrointestinal cancer

Olfactomedin 4 (OLFM4) is a secreted glycoprotein predominantly expressed in bone marrow and gastrointestinal tissues. Aberrant expression of OLFM4 has been shown in several cancers. However, the clinical significance hereof is currently controversial. OLFM4 has been proposed as a candidate biomarker of gastrointestinal cancers. To address this, we developed monoclonal antibodies against synthetic peptides representing various segments of OLFM4. We examined expression of OLFM4 in epithelial cells by immunohistochemistry and found that OLFM4 is highly expressed in proliferating benign epithelial cells and in some carcinoma cells. We developed an Enzyme Linked Immunosorbent Assay for OLFM4 and investigated whether plasma levels of OLFM4 reflect colorectal malignancies, but were unable to see any such association. Instead, we observed two populations of individuals with respect to OLFM4 levels in plasma, the majority with OLFM4 in plasma between 0 and 0.1 μg/ml, mean 0.028 μg/ml while 10% of both normals and patients with cancers had OLFM4 between 4 and 60 μg/ml, mean 15 μg/ml. The levels were constant over time. The background for this high plasma level is not known, but must be taken into account if OLFM4 is used as biomarker for GI cancers.

Intestinal epithelial HuR modulates distinct pathways of proliferation and apoptosis and attenuates small intestinal and colonic tumor development

HuR is a ubiquitous nucleocytoplasmic RNA-binding protein that exerts pleiotropic effects on cell growth and tumorigenesis. In this study, we explored the impact of conditional, tissue-specific genetic deletion of HuR on intestinal growth and tumorigenesis in mice. Mice lacking intestinal expression of HuR (Hur (IKO) mice) displayed reduced levels of cell proliferation in the small intestine and increased sensitivity to doxorubicin-induced acute intestinal injury, as evidenced by decreased villus height and a compensatory shift in proliferating cells. In the context of Apc(min/+) mice, a transgenic model of intestinal tumorigenesis, intestinal deletion of the HuR gene caused a three-fold decrease in tumor burden characterized by reduced proliferation, increased apoptosis, and decreased expression of transcripts encoding antiapoptotic HuR target RNAs. Similarly, Hur(IKO) mice subjected to an inflammatory colon carcinogenesis protocol [azoxymethane and dextran sodium sulfate (AOM-DSS) administration] exhibited a two-fold decrease in tumor burden. Hur(IKO) mice showed no change in ileal Asbt expression, fecal bile acid excretion, or enterohepatic pool size that might explain the phenotype. Moreover, none of the HuR targets identified in Apc(min/+)Hur(IKO) were altered in AOM-DSS-treated Hur(IKO) mice, the latter of which exhibited increased apoptosis of colonic epithelial cells, where elevation of a unique set of HuR-targeted proapoptotic factors was documented. Taken together, our results promote the concept of epithelial HuR as a contextual modifier of proapoptotic gene expression in intestinal cancers, acting independently of bile acid metabolism to promote cancer. In the small intestine, epithelial HuR promotes expression of prosurvival transcripts that support Wnt-dependent tumorigenesis, whereas in the large intestine epithelial HuR indirectly downregulates certain proapoptotic RNAs to attenuate colitis-associated cancer. Cancer Res; 74(18); 5322-35. ©2014 AACR.

Deletion of the olfactomedin 4 gene is associated with progression of human prostate cancer

The olfactomedin 4 (OLFM4) gene is located on chromosome 13q14.3, which frequently is deleted in human prostate cancer. However, direct genetic evidence of OLFM4 gene alteration in human prostate cancer has not yet been obtained. In this study, we investigated the genetics, protein expression, and functions of the OLFM4 gene in human prostate cancer. We found overall 25% deletions within the OLFM4 gene in cancerous epithelial cells compared with adjacent normal epithelial cells that were microdissected from 31 prostate cancer specimens using laser-capture microdissection and genomic DNA sequencing. We found 28% to 45% hemizygous and 15% to 57% homozygous deletions of the OLFM4 gene via fluorescence in situ hybridization analysis from 44 different prostate cancer patient samples. Moreover, homozygous deletion of the OLFM4 gene significantly correlated with advanced prostate cancer. By using immunohistochemical analysis of 162 prostate cancer tissue array samples representing a range of Gleason scores, we found that OLFM4 protein expression correlated inversely with advanced prostate cancer, consistent with the genetic results. We also showed that a truncated mutant of OLFM4 that lacks the olfactomedin domain eliminated suppression of PC-3 prostate cancer cell growth. Together, our findings indicate that OLFM4 is a novel candidate tumor-suppressor gene for chromosome 13q and may shed new light on strategies that could be used for the diagnosis, prognosis, and treatment of prostate cancer patients.

Oestrogen receptor-mediated expression of Olfactomedin 4 regulates the progression of endometrial adenocarcinoma

Endometrial adenocarcinoma is the most common tumour of the female genital tract in developed countries, and oestrogen receptor (ER) signalling plays a pivotal role in its pathogenesis. When we used bioinformatics tools to search for the genes contributing to gynecological cancers, the expression of Olfactomedin 4 (OLFM4) was found by digital differential display to be associated with differentiation of endometrial adenocarcinoma. Aberrant expression of OLFM4 has been primarily reported in tumours of the digestive system. The mechanism of OLFM4 in tumuorigenesis is elusive. We investigated OLFM4 expression in endometrium, analysed the association of OLFM4 with ER signalling in endometrial adenocarcinoma, and examined the roles of OLFM4 in endometrial adenocarcinoma. Expression of OLFM4 was increased during endometrial carcinogenesis, linked to the differentiation of endometrioid adenocarcinoma, and positively related to the expression of oestrogen receptor-α (ERα) and progesterone receptor. Moreover, ERα-mediated signalling regulated expression of OLFM4, and knockdown of OLFM4 enhanced proliferation, migration and invasion of endometrial carcinoma cells. Down-regulation of OLFM4 was associated with decreased cumulative survival rate of patients with endometrioid adenocarcinoma. Our data suggested that impairment of ERα signal-mediated OLFM4 expression promoted the malignant progression of endometrioid adenocarcinoma, which may have significance for the therapy of this carcinoma.