Promotive role of recombinant HE4 protein in proliferation and carboplatin resistance in ovarian cancer cells

Drug resistance biomarkers in ovarian cancer: a bibliometric study from 2017 to 2022

Background

Late diagnosis and patient relapse, mainly due to chemoresistance, are the key reasons for the high mortality rate of ovarian cancer patients. Hence, the search for biomarkers of high predictive value within the phenomenon of chemoresistance is vital. This study performs a bibliometric analysis of the scientific literature concerning biomarkers of drug resistance in ovarian cancer, considering the period from 2017 to 2022.

Methods

The terms "drug resistance biomarker" and "ovarian cancer" were linked by the Boolean operator "AND". The search was done in PubMed, selecting documents published over the last 5 years (2017-2022), which were analyzed with the open-source tool Bibliometrix developed in the R package. The language of the publications was restricted to English. Several types of papers such as case reports, clinical trials, comparative studies, and original articles were considered.

Results

A total of 335 scientific articles were analyzed. The United States and China were the leading contributors and established the largest number of scientific collaborations. The Huazhong University of Science and Technology and the University of Texas MD Anderson Cancer Center were the most influential institutions. The Journal of Ovarian Research, International Journal of Molecular Science, and Scientific Reports are among the most relevant journals. The study identified high-profile, relevant thematic niches and important descriptors that indicate topics of interest, including studies on women, cell lines, solid tumors, and gene expression regulation. As well as studies involving middle-aged and adult participants, and those focusing on prognosis evaluation. Descriptors such as "drug resistance," "neoplasm," "genetics," "biomarker," "gene expression profile," and "drug therapy" would indicate new research trends. In addition, we propose that BCL-2, CHRF, SNAIL, miR-363, iASPP, ALDH1, Fzd7, and EZH2 are potential biomarkers of drug resistance.

Conclusions

This paper contributes to the global analysis of the scientific investigation related to drug resistance biomarkers in ovarian cancer to facilitate further studies and collaborative networks, which may lead to future improvements in therapy for this lethal disease.

Versatile whey acidic protein four-disulfide core domain proteins: biology and role in diseases

The Whey acidic protein four-disulfide core (WFDC) protein family consists of proteins with one or more WFDC domains which are ubiquitously expressed throughout the body of human and perform a wide range of functions, including antiprotease, antibacterial, and immunomodulatory functions. Aberrant expression of WFDC proteins is associated with human diseases. However, review on the WFDC protein family is limited and insufficient. Furthermore, a systematic summary of the underlying mechanisms of WFDC protein activity is lacking. In this review, we give a summary of the structural basis and molecular function of these proteins and review the immune regulatory mechanisms and signaling pathways of WFDC proteins in the development of certain diseases. Furthermore, we discuss the diagnostic and prognostic potential of multiple WFDC proteins in the aforementioned conditions, as well as their prospective use. At last, we also discuss the progress of WFDC protein in clinical trials and put forward some research difficulties and the directions of follow-up research. Our review highlights the functional diversity and clinical significance of WFDC proteins family, while providing potential targets for drug development and innovative therapeutic strategies, this review lays the foundation and direction for future research on WFDC proteins.

The Role of Interleukin 6 (IL6), Cancer Antigen-125 (CA-125), and Human Epididymis Protein 4 (HE4) to predict tumor resectability in the advanced epithelial ovarian cancer patients

INTRODUCTION

A study of tumor resectability in pre-operative patients with advanced epithelial ovarian cancer is required to predict primary surgical benefits accurately. This study aims to investigate IL6, CA-125 and HE4 to predict tumor resectability in the pre-operative patients with advanced epithelial ovarian cancer.

METHODS

This cross-sectional study was conducted in the polyclinic, oncology and gynecology inpatient room of Dr. M. Jamil Padang Hospital from June until December 2022. Advanced epithelial ovarian cancer stage based on histology result from FIGO stages IIIB-IVA. IL6, CA-125, and HE4 were measured using ECLIA (electrochemiluminescence immunoassay). Categorical data were assessed using Chi-square and Mann-Whitney tests. Numerical variable correlations were analyzed using Pearson Correlation tests. While the correlation between numerical and nominal variables was analyzed using the Eta correlation test. A p-value of <0,05 was considered a significant correlation. The cut-off value of serum IL6, CA-125, and HE4 was determined with a ROC curve. The sensitivity and specificity of each clinical parameter were calculated.

RESULTS

There was a significant difference in IL-6 (1328 vs 752 pg/ml; p<0,001), CA-125 (1260,5 vs 819,5 U/ml; p<0,001), and HE4 levels (1320 vs 760 pmol/L; p<0,001) between patients with tumor resectability of > 1 cm (suboptimal) vs < 1 cm (optimal). There was a correlation between IL6 (r = 0,832), CA-125 (r = 0,716), and HE4 (r = 0,716) with tumor resectability.

CONCLUSION

Measuring IL6, CA-125, and HE4 levels is useful for clinicians to predict tumor resectability in pre-operative patients with advanced epithelial ovarian cancer.

Recent Insight about HE4 Role in Ovarian Cancer Oncogenesis

Currently, ovarian cancer (OC) is a target of intense biomarkers research because of its frequent late diagnosis and poor prognosis. Serum determination of Human epididymis protein 4 (HE4) is a very important early detection test. Most interestingly, HE4 plays a unique role in OC as it has been implicated not only in OC diagnosis but also in the prognosis and recurrence of this lethal neoplasm, actually acting as a clinical biomarker. There are several evidence about the predictive power of HE4 clinically, conversely less has been described concerning its role in OC oncogenesis. Based on these considerations, the main goal of this review is to clarify the role of HE4 in OC proliferation, angiogenesis, metastatization, immune response and also in the development of targeted therapy. Through a deeper understanding of its functions as a key molecule in the oncogenetic processes underlying OC, HE4 could be possibly considered as an essential resource not only for diagnosis but also for prognosis and therapy choice.

The Proteolytic Landscape of Ovarian Cancer: Applications in Nanomedicine

Ovarian cancer (OvCa) is one of the leading causes of mortality globally with an overall 5-year survival of 47%. The predominant subtype of OvCa is epithelial carcinoma, which can be highly aggressive. This review launches with a summary of the clinical features of OvCa, including staging and current techniques for diagnosis and therapy. Further, the important role of proteases in OvCa progression and dissemination is described. Proteases contribute to tumor angiogenesis, remodeling of extracellular matrix, migration and invasion, major processes in OvCa pathology. Multiple proteases, such as metalloproteinases, trypsin, cathepsin and others, are overexpressed in the tumor tissue. Presence of these catabolic enzymes in OvCa tissue can be exploited for improving early diagnosis and therapeutic options in advanced cases. Nanomedicine, being on the interface of molecular and cellular scales, can be designed to be activated by proteases in the OvCa microenvironment. Various types of protease-enabled nanomedicines are described and the studies that focus on their diagnostic, therapeutic and theranostic potential are reviewed.

Interaction between TMEFF1 and AHNAK proteins in ovarian cancer cells: Implications for clinical prognosis

TMEFF1 is a newly discovered protein involved in the physiological functions of the central nervous system, embryonic development, and other biological processes. Our previous study revealed that TMEFF1 acts as a tumor-promoting gene in ovarian cancer. AHNAK, as a giant scaffolding protein, plays a role in the formation of the blood-brain barrier, cell architecture and the regulation of cardiac calcium channels. However, its role in ovarian cancer remains poorly researched. In this study, we detected the expression of AHNAK and TMEFF1 in 148 different ovarian cancer tissues, determined their relationship with pathological parameters and prognosis, clarified the interaction between the two proteins, and explored the related cancer-promoting mechanisms through immunohistochemistry, immunoprecipitation, immunofluorescence double staining, western blotting, and bioinformatics. The high expression of ANHAK and TMEFF1 in ovarian cancer indicated a higher degree of tumor malignancy and a worse prognosis. Furthermore, the expression of TMEFF1 and AHNAK was significantly positively correlated. The results also showed that AHNAK and TMEFF1 co-localized and interacted with each other in ovarian cancer tissues and cells. And knockdown of AHNAK promoted proliferation, migration and invasion of ovarian cancer cells in vitro. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that AHNAK and related genes were enriched during mitosis regulation, cytoskeleton formation, gene epigenetics, etc., whereas TMEFF1 and related genes are enriched during immune regulation and other processes. We also clarified the network of kinases, microRNA, and transcription factor targets, and the impact of genetic mutations on prognosis. Notably, AHNAK was regulated by the expression of TMEFF1 and can activate the MAPK pathways. Overall, high expression of AHNAK and TMEFF1 in ovarian cancer cells indicated a higher degree of tumor malignancy and a worse prognosis. Therefore, the interaction between AHNAK and TMEFF1 may become a potential anti-tumor target for ovarian cancer treatment.

Targeting and neutralizing human epididymis protein 4 by novel nanobodies to suppress ovarian cancer cells and attenuate cisplatin resistance

Human epididymis protein 4 (HE4) is a glycoprotein secreted by epithelial ovarian cancer (EOC) cells and is a novel and specific biomarker for diagnosing and prognosing EOC. Previous studies have shown that overexpression of HE4 is correlated with EOC tumorigenesis and chemoresistance. However, less has been reported regarding the direct effect of the secreted HE4 protein as an autocrine factor in EOC cells. Here, we investigated the molecular mechanism of the secretory form of HE4 on the growth of EOC cells by applying nanobodies with a targeted interaction of free HE4. Three anti-HE4 nanobodies were selected from an immune library by phage display. HE4 secreted by serum-free cultured OVCAR3 cells increased and was effectively neutralized by anti-HE4 nanobodies, which inhibited cell viability. Treatment with the anti-HE4 nanobody 1G8 decreased Bcl-2 expression and increased BAX, cleaved PARP, and p53 levels, resulting in apoptosis of OVCAR3 cells. Moreover, 1G8 significantly improved the cisplatin response of OVCAR3 cells. Our data suggest that secretory HE4 played a novel pro-survival autocrine role and was a target of the anti-HE4 nanobody to improve the therapeutic effects of cisplatin-based chemotherapy.

Human Epididymis Protein 4 and Lewis y Enhance Chemotherapeutic Resistance in Epithelial Ovarian Cancer Through the p38 MAPK Pathway

INTRODUCTION

Ovarian cancer has a high mortality rate due to difficulties in early detection and chemotherapy resistance. Human epididymal protein 4 (HE4) has been adopted as a novel serum biomarker for early ovarian cancer diagnosis, and the presence of Lewis y antigen modifications on HE4 in ovarian cancer cell lines has been detected in previous studies. The aim of this study was to analyze the expression of HE4 and Lewis y antigen in human ovarian cancer in order to find a correlation between them, as well as with the clinical pathological parameters of patients with ovarian cancer.

METHODS

Immunohistochemistry was used to detect the respective expression of these compounds in two patient groups (chemotherapy-resistant and chemotherapy-sensitive) containing a total of 95 patients. Then, a bioinformatic approach was adopted and online large sample databases (TCGA, CCLE, and GTEx; Metascape, Cytoscape) were used to explore the potential mechanisms of action of these compounds.

RESULTS

The results of this study demonstrate that high HE4 and Lewis y expression could be used as markers for chemotherapy resistance and poor prognosis in patients with ovarian cancer. These two expression events were widely correlated in various cancer tissues and are thought to act by activating the p38 mitogen-activated protein kinases (MAPK) pathway and inducing Vascular Endothelial Growth Factor A (VEGFA), Prostaglandin-Endoperoxide Synthase 2 (PTGS2), Early Growth Response 1 (EGR1), and Hypoxia-Inducible Factor 1-Alpha (HIFI1A), thereby promoting malignant biological behavior and resistance in ovarian cancer.

CONCLUSIONS

These findings not only reveal the possible mechanism by which HE4 and Lewis y antigen affect ovarian cancer but also identify a four-gene signature that could be very useful in ovarian cancer detection and/or the development of new targeted therapies.

Role of BRCA Mutation and HE4 in Predicting Chemotherapy Response in Ovarian Cancer: A Retrospective Pilot Study

Even though 80% of patients with High-Grade Serous Ovarian Cancer respond to standard first-line chemotherapy, a majority of them could relapse in the following five years due to a resistance to platinum. Human Epididymis protein 4 (HE4) is one of the most promising markers in predicting platinum therapy response. This pilot study aims to evaluate the potential role of HE4 value in predicting chemotherapy response in BRCA mutated patients and in BRCA wild-type (non-mutated) ones. We selected 69 patients, affected by High-Grade Serous Ovarian Cancer, and optimally debulked and submitted to standard chemotherapy protocols. HE4 was dosed during every chemotherapy course. Patients were classified as platinum-resistant and platinum-sensitive. According to BRCA mutation test, patients were further divided into BRCA wild-type (53 patients), and BRCA mutated (16 patients). 35 patients out of 69 (52%) were platinum-sensitive (recurrence > 12 months), while 33 patients (48%) were platinum-resistant (recurrence < 12 months). Thus, in the total population, HE4 performed as a marker of chemosensitivity with a sensibility of 79% and a specificity of 97%. In the BRCA WT group, 23 patients out of 53 (43%) were platinum-sensitive, while 30 patients out of 53 (57%) were platinum-resistant. In the BRCA WT group, HE4 performed as a predictive marker of chemosensitivity with a sensibility of 80% and a specificity of 100%. In the BRCA mutated group, 13 patients out of 16 (82%) were platinum-sensitive, while 3 patients (18%) were platinum-resistant. In the BRCA mutated group, HE4 performed as a predictive marker of chemosensitivity in all patients. The ability to detect platinum-resistant patients before tumor relapse probably could open new therapeutic scenarios.

Serum D-dimer, albumin and systemic inflammatory response markers in ovarian clear cell carcinoma and their prognostic implications

Background

This study attempts to evaluate whether preoperative systemic inflammatory response (SIR) markers or other hematological variables, such as albumin, D-dimer, and carbohydrate antigen 125, play roles in predicting chemotherapy response and survival outcome in patients with ovarian clear cell carcinoma (OCCC).

Methods

Preoperative leukocyte differential counts, as well as platelet, serum albumin, plasma D-dimer and CA-125 levels, were measured in patients with FIGO IC-IV ovarian clear cell cancer. The correlations of these hematological biomarkers with clinicopathological features, chemotherapy response, and survival outcomes were further analyzed. Survival time was estimated using the Kaplan-Meier model, whereas Cox regression was conducted for multivariate analysis.

Results

Among the 84 patients, 28.6% were classified as platinum resistant, and 69.0% were platinum sensitive. Preoperative CA125, albumin, and D-dimer levels; neutrophil to lymphocyte ratios (NLR); and monocyte to lymphocyte ratios were significantly correlated with FIGO stage, residual tumor, and platinum response. Platelet to lymphocyte ratio was not related to platinum response (P = 0.060). The median follow-up time was 28 months (range, 1 to 128 months). Preoperative CA125, albumin, and D-dimer levels were significant prognostic factors for overall survival (OS) and progression-free survival (PFS). In the univariate analysis, only NLR exhibited prognostic significance for PFS (P = 0.007). Multivariate analysis indicated that D-dimer > 3.27 (P = 0.001 for OS; P = 0.040 for PFS) and albumin < 39.6 (P = 0.005 for OS and P = 0.041 for PFS) retained significance.

Conclusions

Preoperative NLR has some predictive value for platinum resistance in patients with IC-IV stage OCCC but has little predictive effect on prognosis. Elevated D-dimer and reduced albumin might be potential biomarkers for worse response to first-line platinum-based chemotherapy and poor clinical outcomes.

The biomarker HE4 (WFDC2) promotes a pro-angiogenic and immunosuppressive tumor microenvironment via regulation of STAT3 target genes

Epithelial ovarian cancer (EOC) is a highly lethal gynecologic malignancy arising from the fallopian tubes that has a high rate of chemoresistant recurrence and low five-year survival rate. The ovarian cancer biomarker HE4 is known to promote proliferation, metastasis, chemoresistance, and suppression of cytotoxic lymphocytes. In this study, we sought to examine the effects of HE4 on signaling within diverse cell types that compose the tumor microenvironment. HE4 was found to activate STAT3 signaling and promote upregulation of the pro-angiogenic STAT3 target genes IL8 and HIF1A in immune cells, ovarian cancer cells, and endothelial cells. Moreover, HE4 promoted increases in tube formation in an in vitro model of angiogenesis, which was also dependent upon STAT3 signaling. Clinically, HE4 and IL8 levels positively correlated in ovarian cancer patient tissue. Furthermore, HE4 serum levels correlated with microvascular density in EOC tissue and inversely correlated with cytotoxic T cell infiltration, suggesting that HE4 may cause deregulated blood vessel formation and suppress proper T cell trafficking in tumors. Collectively, this study shows for the first time that HE4 has the ability to affect signaling events and gene expression in multiple cell types of the tumor microenvironment, which could contribute to angiogenesis and altered immunogenic responses in ovarian cancer.

HE4 overexpression decreases pancreatic cancer Capan-1 cell sensitivity to paclitaxel via cell cycle regulation

BACKGROUND

Paclitaxel is a first-line chemotherapy drug for pancreatic, ovarian, endometrial cancers and other malignancies. However, its efficacy is often compromised by decreased cell sensitivity or the development of resistance. Human epididymis protein 4 (HE4) is highly expressed in gynecologic and pancreatic cancer tissues, and its serum levels are used for patient triage and assistant diagnosis of gynecologic cancers. Previous studies have shown that HE4 overexpression could promote cancer cell proliferation and the growth of tumor xenografts, which suggests its potential involvement in cancer chemosensitivity.

METHODS

Two pancreatic cancer cell lines, Capan-1 and Suit-2, were transiently transfected with an HE4 overexpression plasmid, and transfected cells were treated with paclitaxel. S-phase cells were labeled using BrdU, and cell positivity rates were determined by counting BrdU-positive cells. Following HE4 overexpression and/or drug treatment, a western blotting analysis was performed to determine the protein alterations of PCNA and p21, two important cell cycle regulators.

RESULTS

HE4 overexpression not only promoted the proliferation of the Capan-1 pancreatic cells, but also significantly decreased cell sensitivity to paclitaxel. Results from western blotting showed that paclitaxel inhibited cell proliferation by decreasing the expression of PCNA and increasing the expression of p21. Data analysis indicated interactive actions between HE4 function and paclitaxel effects, both converging to cell cycle regulation.

CONCLUSION

These findings suggest that HE4 could be a potential therapeutic target for the sensitization of pancreatic cancer cells to paclitaxel treatment. HE4 expression levels may be used to predict the sensitivity of pancreatic cancer patients to paclitaxel.

Is HE4 Superior over CA-125 in the Follow-up of Patients with Epithelial Ovarian Cancer?

Notwithstanding important advances in the treatment of epithelial ovarian cancer (EOC), this disease is still a leading cause of global high mortality from gynecological malignancies. Recurrence in EOC is inevitable and it is responsible for poor survival rates. There is a critical need for novel effective biomarkers with improved accuracy compared to the standard carbohydrate antigen-125 (CA-125) for follow-up. The human epididymis protein 4 (HE4) is used for early detection of EOC (ROMA algorithm) as well as for predicting optimal cytoreduction after neoadjuvant chemotherapy and survival outcomes. Notably, the emerging HE4 is a promising prognostic biomarker that has displayed better accuracy in various recent studies for detecting recurrent disease. In this mini-review, we discussed the potential of HE4 as an accurate predictor of EOC recurrence.

Interaction of HE4 and ANXA2 exists in various malignant cells-HE4-ANXA2-MMP2 protein complex promotes cell migration

Background

The interaction between human epididymis protein 4 (HE4) and annexin A2 (Annexin A2) has been found in ovarian cancer. However, it is dimness whether the interaction exists in other malignant tumors.

Methods

Real-time PCR, western blotting and immunocytochemistry were used to detect mRNA and proteins expression. Co-immunoprecipitation and double-labeling immunofluorescence were used to detect the interaction among HE4, ANXA2 and MMP2. MTS assay was used to test cell proliferation. Adhesion test was used to test cell adhesion. Flow cytometry was applied to examine cell cycle. The scratch test and Transwell assay was performed to detect the migration and invasion of various malignant cell lines.

Results

Here we show that the overexpression of HE4 and ANXA2 in various malignant cells is a common phenomenon. HE4 and ANXA2 are co-localized in the cytoplasm and membrane of various tumor cells. ES-2 cells which had both high expression of HE4 and ANXA2 were much stronger in proliferation, adhesion, invasion, and migration than other tumor cells. HE4–ANXA2–MMP2 could form a triple protein complex. HE4 could mediate the expression of MMP2 via ANXA2 to promote cell migration progress.

Conclusions

The interaction of HE4 and ANXA2 exists in various types of cancer cells. HE4 and ANXA2 can promote the proliferation, adhesion, invasion, and migration of cancer cells. HE4–ANXA2–MMP2 form a protein complex and ANXA2 plays the role of “bridge”. They performed together to promote cell migration.

Human Epididymis Secretory Protein 4 (HE4) Compromises Cytotoxic Mononuclear Cells via Inducing Dual Specificity Phosphatase 6

While selective overexpression of serum clinical biomarker Human epididymis secretory protein 4 (HE4) is indicative of ovarian cancer tumorigenesis, much is still known about the mechanistic role of the HE4 gene or gene product. Here, we examine the role of the secretory glycoprotein HE4 in ovarian cancer immune evasion. Through modified subtractive hybridization analyses of human peripheral blood mononuclear cells (PBMCs), we have characterized gene targets of HE4 and established a preliminary mechanism of HE4-mediated immune failure in ovarian tumors. Dual specificity phosphatase 6 (DUSP6) emerged as the most upregulated gene in PBMCs upon in vitro exposure to HE4. DUSP6 was found to be upregulated in CD8⁺ cells and CD56⁺ cells. HE4 exposure reduced Erk1/2 phosphorylation specifically in these cell populations and the effect was erased by co-incubation with a DUSP6 inhibitor, (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one (BCI). In co-culture with PBMCs, HE4-silenced SKOV3 human ovarian cancer cells exhibited enhanced proliferation upon exposure to external HE4, while this effect was partially attenuated by adding BCI to the culture. Additionally, the reversal effects of BCI were erased in the co-culture with CD8⁺ / CD56⁺ cell deprived PBMCs. Taken together, these findings show that HE4 enhances tumorigenesis of ovarian cancer by compromising cytotoxic CD8⁺ and CD56⁺ cells through upregulation of self-produced DUSP6.

Beyond the Biomarker: Understanding the Diverse Roles of Human Epididymis Protein 4 in the Pathogenesis of Epithelial Ovarian Cancer

Human epididymis protein 4 (HE4) is an important clinical biomarker used for the detection of epithelial ovarian cancer (EOC). While much is known about the predictive power of HE4 clinically, less has been reported regarding its molecular role in the progression of EOC. A deeper understanding of HE4’s mechanistic functions may help contribute to the development of novel targeted therapies. Thus far, it has been difficult to recommend HE4 as a therapeutic target owing to the fact that its role in the progression of EOC has not been extensively evaluated. This review summarizes what is collectively known about HE4 signaling and how it functions to promote tumorigenesis, chemoresistance, and metastasis in EOC, with the goal of providing valuable insights that will have the potential to aide in the development of new HE4-targeted therapies.

Increased HE4 mRNA Expression Correlates with High Level Of eIF3a mRNA And Better Survival in Women with Epithelial Ovarian Cancer

Human epididymis protein 4 (HE4) is one of the most promising biomarkers for epithelial ovarian cancer (EOC). The majority of previous studies utilized the serum level or tissue protein expression of HE4 based upon immunohistochemistry (IHC) to evaluate the role of HE4 in the diagnosis, prognosis, and surveillance of EOC, but very little is known about HE4 mRNA expression. Eukaryotic translation initiation factor 3a (eIF3a) is implicated in oncogenesis and has been investigated extensively as a potential biomarker for malignancy. We previously reported a positive correlation between IHC expressions of eIF3a and HE4 in EOC. In the present study, we performed RT-PCR to determine mRNA expressions of HE4 and eIF3a in 30 normal ovarian tissues, 45 benign, 20 borderline and 94 malignant ovarian tumors. The association of HE4 and eIF3a mRNA expressions with clinicopathological characteristics and patient survivals was investigated. IHC was also performed in the same participants to investigate the correlation between mRNA and protein levels of HE4. HE4 mRNA level was found to be 48.42 ± 74.55 (mean ± SD, range: 0.01-343.99), significantly higher in primary EOC than in the borderline tumor, benign tumor, and normal ovarian tissue (P<0.001). The cutoff value was 13.99 for HE4 to discriminate malignant from benign tumors at 68.1% sensitivity and 93.0% specificity. By Spearman's correlation test, HE4 mRNA expression was indicated to positively correlate with serum CA125 level (r=0.530, P<0.001). Higher HE4 mRNA expression was associated with decreased frequency of lymph node metastasis (P=0.038) and better overall survival (OS) (P=0.007) in primary EOC. Multivariable analysis showed an independent prognostic value of the relative mRNA level of HE4 greater than one for OS (Hazard Ratio, 0.069, 95%CI, 0.009-0.530, P=0.010). eIF3a mRNA expression in women with primary EOC was 0.95 ± 1.19 (mean ± SD, range: 0.06-7.46), which was in a positive linear correlation with HE4 mRNA expression (r=0.310, P=0.002). In the present study, the HE4 mRNA level was unparalleled with IHC expression of HE4 (P>0.05). Collectively, our study revealed that increased HE4 mRNA expression correlates with high level of eIF3a mRNA and better survival in women with EOC, which calls for further investigations.

Human Epididymis Protein 4 Promotes Events Associated with Metastatic Ovarian Cancer via Regulation of the Extracelluar Matrix

Human epididymis protein 4 (HE4) has received much attention recently due to its diagnostic and prognostic abilities for epithelial ovarian cancer. Since its inclusion in the Risk of Ovarian Malignancy Algorithm (ROMA), studies have focused on its functional effects in ovarian cancer. Here, we aimed to investigate the role of HE4 in invasion, haptotaxis, and adhesion of ovarian cancer cells. Furthermore, we sought to gain an understanding of relevant transcriptional profiles and protein kinase signaling pathways mediated by this multifunctional protein. Exposure of OVCAR8 ovarian cancer cells to recombinant HE4 (rHE4) promoted invasion, haptotaxis toward a fibronectin substrate, and adhesion onto fibronectin. Overexpression of HE4 or treatment with rHE4 led to upregulation of several transcripts coding for extracellular matrix proteins, including SERPINB2, GREM1, LAMC2, and LAMB3. Gene ontology indicated an enrichment of terms related to extracellular matrix, cell migration, adhesion, growth, and kinase phosphorylation. LAMC2 and LAMB3 protein levels were constitutively elevated in cells overexpressing HE4 and were upregulated in a time-dependent manner in cells exposed to rHE4 in the media. Deposition of laminin-332, the heterotrimer comprising LAMC2 and LAMB3 proteins, was increased in OVCAR8 cells treated with rHE4 or conditioned media from HE4-overexpressing cells. Enzymatic activity of matriptase, a serine protease that cleaves laminin-332 and contributes to its pro-migratory functional activity, was enhanced by rHE4 treatment in vitro. Proteomic analysis revealed activation of focal adhesion kinase signaling in OVCAR8 cells treated with conditioned media from HE4-overexpressing cells. Focal adhesions were increased in cells treated with rHE4 in the presence of fibronectin. These results indicate a direct role for HE4 in mediating malignant properties of ovarian cancer cells and validate the need for HE4-targeted therapies that will suppress activation of oncogenic transcriptional activation and signaling cascades.

Overexpression of HE4 (human epididymis protein 4) enhances proliferation, invasion and metastasis of ovarian cancer

Overexpression of Human epididymis protein 4 (HE4) related with a role in ovarian cancer tumorigenesis while little is known about the molecular mechanism alteration by HE4 up regulation. Here we reported that overexpressed HE4 promoted ovarian cancer cells proliferation, invasion and metastasis. Furthermore, human whole genome gene expression profile microarrays revealed that 231 differentially expressed genes (DEGs) were altered in response to HE4, in which MAPK signaling, ECM receptor, cell cycle, steroid biosynthesis pathways were involved. The findings suggested that overexpressed HE4 played an important role in ovarian cancer progression and metastasis and that HE4 has the potential to serve as a novel therapeutic target for ovarian cancer.

Gene expression profile analysis in response to α1,2-fucosyl transferase (FUT1) gene transfection in epithelial ovarian carcinoma cells

The aim of this study was to identify differentially expressed genes (DEGs) in response to α1,2-fucosyl transferase (FUT1) gene transfection in epithelial ovarian cancer cells. Human whole-genome oligonucleotide microarrays were used to determine whether gene expression profile may differentiate the epithelial ovarian cell line Caov-3 transfected with FUT1 from the empty plasmid-transfected cells. Quantitative real-time PCR and immunohistochemical staining validated the microarray results. Gene expression profile identified 215 DEGs according to the selection criteria, in which 122 genes were upregulated and 93 genes were downregulated. Gene Ontology (GO) and canonical pathway enrichment analysis were applied, and we found that these DEGs are involved in BioCarta mammalian target of rapamycin (mTOR) pathway, BioCarta eukaryotic translation initiation factor 4 (EIF4) pathway, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in cancer. Interaction network analysis predicted genes participating in the regulatory connection. Highly differential expression of TRIM46, PCF11, BCL6, PTEN, and FUT1 genes was validated by quantitative real-time PCR in two cell line samples. Finally, BCL6 and Lewis Y antigen were validated at the protein level by immunohistochemistry in 103 paraffin-embedded ovarian cancer tissues. The identification of genes in response to FUT1 may provide a theoretical basis for the investigations of the molecular mechanism of ovarian cancer.

Analysis of the gene expression profile in response to human epididymis protein 4 in epithelial ovarian cancer cells

Currently, there are emerging multiple studies on human epididymis protein 4 (HE4) in ovarian cancer. HE4 possesses higher sensitivity and specificity than CA125 in the confirmative early diagnosis for ovarian cancer. Although much attention has been given to explore its clinical application, research of the basic mechanisms of HE4 in ovarian cancer are still unclear. In the present study, we provide fundamental data to identify full-scale differentially expressed genes (DEGs) in response to HE4 by use of human whole-genome microarrays in human epithelial ovarian cancer cell line ES-2 following overexpression and silencing of HE4. We found that a total of 717 genes were upregulated and 898 genes were downregulated in the HE4-overexpressing cells vs. the HE4-Mock cells, and 166 genes were upregulated and 285 were downregulated in the HE4-silenced cells vs. the HE4-Mock cells. An overlap of 16 genes consistently upregulated and 8 genes downregulated in response to HE4 were noted. These DEGs were involved in MAPK, steroid biosynthesis, cell cycle, the p53 hypoxia pathway, and focal adhesion pathways. Interaction network analysis predicted that the genes participated in the regulatory connection. Highly differential expression of the FOXA2, SERPIND1, BDKRD1 and IL1A genes was verified by quantitative real-time PCR in 4 cell line samples. Finally, SERPIND1 (HCII) was validated at the protein level by immunohistochemistry in 107 paraffin-embedded ovarian tissues. We found that SERPIND1 may act as a potential oncogene in the development of ovarian cancer. The present study displayed the most fundamental and full-scale data to show DEGs in response to HE4. These identified genes may provide a theoretical basis for investigations of the underlying molecular mechanism of HE4 in ovarian cancer.

HE4 promotes collateral resistance to cisplatin and paclitaxel in ovarian cancer cells

Background

Chemotherapy resistance presents a difficult challenge in treating epithelial ovarian cancer patients, particularly when tumors exhibit resistance to multiple chemotherapeutic agents. A few studies have shown that elevated serum levels of the ovarian cancer biomarker HE4 correlate with tumor chemoresistance, response to treatment, and survival. Here, we sought to confirm our previous results that HE4 contributes to collateral resistance to cisplatin and paclitaxel in vitro and uncover factors that may contribute to HE4-mediated chemoresistance.

Methods

MTS assays and western blots for cleaved PARP were used to assess resistance of HE4-overexpressing SKOV3 and OVCAR8 clones to cisplatin and paclitaxel. CRISPR/Cas technology was used to knockdown HE4 in HE4-overexpressing SKOV3 cells. A microarray was conducted to determine differential gene expression between SKOV3 null vector-transfected and HE4-overexpressing clones upon cisplatin exposure, and results were validated by quantitative RT-PCR. Regulation of mitogen activated protein kinases (MAPKs) and tubulins were assessed by western blot.

Results

HE4-overexpressing SKOV3 and OVCAR8 clones displayed increased resistance to cisplatin and paclitaxel. Knockdown of HE4 in HE4-overexpressing SKOV3 cells partially reversed chemoresistance. Microarray analysis revealed that HE4 overexpression resulted in suppression of cisplatin-mediated upregulation of EGR1, a MAPK-regulated gene involved in promoting apoptosis. Upregulation of p38, a MAPK activated in response to cisplatin, was suppressed in HE4-overexpressing clones. No differences in extracellular signal-regulated kinase (ERK) activation were noted in HE4-overexpressing clones treated with 25 μM cisplatin, but ERK activation was partially suppressed in HE4-overexpressing clones treated with 80 μM cisplatin. Furthermore, treatment of cells with recombinant HE4 dramatically affected ERK activation in SKOV3 and OVCAR8 wild type cells. Recombinant HE4 also upregulated α-tubulin and β-tubulin levels in SKOV3 and OVCAR8 cells, and microtubule associated protein tau (MAPT) gene expression was increased in SKOV3 HE4-overexpressing clones.

Conclusions

Overexpression of HE4 promotes collateral resistance to cisplatin and paclitaxel, and downregulation of HE4 partially reverses this chemoresistance. Multiple factors could be involved in HE4-mediated chemoresistance, including deregulation of MAPK signaling, as well as alterations in tubulin levels or stability.

Electronic supplementary material

The online version of this article (doi:10.1186/s13048-016-0240-0) contains supplementary material, which is available to authorized users.

Recombinant HE4 protein promotes proliferation of pancreatic and endometrial cancer cell lines

Pancreatic adenocarcinoma is one of the most deadly malignancies, and endometrial cancer represents the most common gynecologic cancer in the USA. Better understanding on the pathologic mechanisms and pathways is required for effective treatment of these malignancies. Recently, human epididymis protein 4 (HE4 or WFDC2), a secretory glycoprotein, was found to be overexpressed in pancreatic and endometrial cancers. In addition, studies have shown that HE4 overexpression in endometrial cancer cell lines led to faster cancer progression in a mouse subcutaneous model. These findings raise a question on the role(s) of secretory, extracellular HE4 in cancer development. In the present study, we found that treatment of pancreatic and endometrial cancer cell lines with purified, extracellular HE4 protein led to a significant increase in cell viability and proliferation. Moreover, extracellular HE4 protein was able to increase DNA synthesis, and modulate the mRNA and protein levels of cell cycle marker PCNA and cell cycle inhibitor p21. These effects appeared to be robust and sustainable and required a relatively low concentration of HE4 protein. The findings indicated the secreted, extracellular HE4 may carry some physiopathological functions. Via paracrine/endocrine actions, circulatory HE4 produced by malignant cells may contribute to pancreatic and endometrial cancer progression and/or metastasis.