Increased serum placenta growth factor level is significantly associated with progression, recurrence and poor prognosis of oral squamous cell carcinoma

Neuropilin-1 and placental growth factor as prognostic factors in metastatic breast cancer

BACKGROUND

Angiogenesis is crucial for tumor development, progression, and metastasizing. The most important regulator of angiogenesis is the vascular endothelial growth factor (VEGF) family, which is involved in multiple pathways in tumor microenvironment. The objective of this study was to investigate the prognostic value of the VEGF family in patients treated for metastatic breast cancer. The emphasis was on neuropilin-1 (NRP-1) and placental growth factor (PlGF).

MATERIALS AND METHODS

An analysis of eight members of the VEGF family was performed using baseline plasma samples of 65 patients treated for metastatic HER2 negative breast cancer in a phase II first-line bevacizumab plus chemotherapy trial. The patients were divided into two groups, high or low, according to the median for each VEGF family member. Progression-free survival (PFS) and overall survival (OS) were determined for each VEGF family member.

RESULTS

The patients with low plasma levels of NRP-1 and PlGF had a longer OS than those with high plasma levels [multivariable adjusted hazard ratios (HRs) 2.54 (95% confidence interval (CI) 1.11-5.82, p = 0.02) and 3.11 (95% CI 1.30-7.47, p = 0.01), respectively]. The patients with low levels of both NRP-1 and PlGF had a remarkably long OS with HR of 6.24, (95% CI 1.97-19.76, p = 0.002). In addition, high baseline NRP-1 level was associated with a significantly shorter PFS [multivariable adjusted HR 2.90 (95% CI 1.02-8.28, p = 0.04)] than that in the low-level group, and a high baseline vascular endothelial growth factor receptor-2 level was associated with a longer PFS [multivariable adjusted HR 0.43 (95% CI 0.19-0.98, p = 0.04)].

CONCLUSION

Especially NRP-1 and PlGF have prognostic potential in metastatic breast cancer patients treated with a bevacizumab-taxane combination. Patients with low plasma levels of NRP-1 or PlGF have longer OS than patients with high levels. Patients with both low NRP-1 and PlGF levels appear to have excellent long-term survival.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00979641, registration date 18/09/2009. The regional Ethics Committee: R08142M, registration date 18/11/2008.

Contemporaneous Perioperative Inflammatory and Angiogenic Cytokine Profiles of Surgical Breast, Colorectal, and Prostate Cancer Patients: Clinical Implications

Surgery-induced tumor growth acceleration and synchronous metastatic growth promotion have been observed for decades. Surgery-induced wound healing, orchestrated through growth factors, chemokines, and cytokines, can negatively impact patients harboring residual or metastatic disease. We provide detailed clinical evidence of this process in surgical breast, prostate, and colorectal cancer patients. Plasma samples were analyzed from 68 cancer patients who had not received treatment before surgery or adjuvant therapy until at least four weeks post-surgery. The levels of plasma cytokines, chemokines, and growth factors were simultaneously quantified and profiled using multiplexed immunoassays for eight time points sampled per patient. The immunologic processes are induced immediately after surgery in patients, characterized by a drastic short-term shift in the expression levels of pro-inflammatory and angiogenic molecules and cytokines. A rapid and significant spike in circulating plasma levels of hepatocyte growth factor (HGF), interleukin-6 (IL-6), placental growth factor (PLGF), and matrix metalloproteinase-9 (MMP-9) after surgery was noted. The rise in these molecules was concomitant with a significant drop in transforming growth factor-β1 (TGF-β1), platelet-derived growth factor (PDGF-AB/BB), insulin-like growth factor-1 (IGF-1), and monocyte chemoattractant protein-2 (MCP-2). If not earlier, each plasma analyte was normalized to baseline levels within 1-2 weeks after surgery, suggesting that surgical intervention alone was responsible for these effects. The effects of surgical tumor removal on disrupting the pro-inflammatory and angiogenic plasma profiles of cancer patients provide evidence for potentiating malignant progression. Our findings indicate a narrow therapeutic window of opportunity after surgery to prevent disease recurrence.

Characterization of the Expression of Angiogenic Factors in Cutaneous Squamous Cell Carcinoma of Domestic Cats

Cutaneous squamous cell carcinoma (CSCC) is a common malignant skin cancer with a significant impact on health, and it is important to determine the degree of reliance of CSCC on angiogenesis for growth and metastasis. Major regulators of angiogenesis are the vascular endothelial growth factor (VEGF) family and their associated receptors. Alternative pre-mRNA splicing produces multiple isoforms of VEGF-A and PLGF with distinct biological properties. Several studies highlight the function of VEGF-A in CSCC, but there are no studies of the different isoforms of VEGF-A and PLGF for this neoplasm. We characterized the expression of three isoforms of VEGF-A, two isoforms of PLGF, and their receptors in cat CSCC biopsies compared to normal haired skin (NHS). Although our results revealed no significant changes in transcript levels of panVEGF-A or their isoforms, the mRNA levels of PLGF I and the receptors Flt-1 and KDR were downregulated in CSCC compared to NHS. Differences were observed in ligand:receptor mRNA expression ratio, with the expression of VEGF-A relative to its receptor KDR higher in CSCC, which is consistent with our hypothesis and prior human SCC studies. Immunolocalization in tissue showed increased expression of all measured factors and receptors in tumor cells compared to NHS and surrounding vasculature. We conclude that the factors measured may play a pivotal role in CSCC growth, although further studies are needed to clarify the role of angiogenic factors in feline CSCC.

Detection of CAF-1/p60 in peripheral blood as a potential biomarker of HNSCC tumors

To date, a very small number of serum biomarkers have been identified for clinical use in squamous carcinomas of the head and neck region. Chromatin Assembly Factor-1 (CAF-1) heterotrimeric complex subunit CAF1/p60 expression levels have been reported to be of prognostic value in Oral Squamous Cell Carcinoma (OSCC), as well as in other human solid tumors. Here our aim was to detect and quantify CAF1/p60 in the peripheral blood of Head and Neck Squamous Cell Carcinoma (HNSCC) patients, and to investigate the possible associations between serum concentration of CAF-1/p60 and HNSCC tumors. A total of 63 HNSCC patients (51 OSCC, 8 OPSCC, 3 laryngeal SCC, and 1 rhinopharynx SCC) and 30 healthy controls were enrolled. The serum levels of CAF-1/p60 were measured by ELISA assay before and after surgery. Serum CAF-1/p60 concentration resulted significantly higher in cancer patients, compared with healthy controls, in pre-surgery samples (P < 0.05). Serum levels of CAF-1/p60 significantly decreased in serum samples taken after surgery (P < 0.05). Our results demonstrated that CAF-1/p60 may be detected in serum, suggesting a role for CAF-1/p60 as potential soluble biomarkers in HNSCC tumors.

Diagnostic Value of Circulating PIGF in Combination with Flt-1 in Early Cervical Cancer

The utility of placental growth factor (PlGF) and its receptor VEGFR-1 (Flt-1) as biomarkers for cervical cancer has not been clarified yet. To address this issue, we investigated the levels of soluble PlGF (sPlGF) and soluble Flt-1 (sFlt-1) in the serum from patients with early cervical cancer, cervical intraepithelial neoplasia (CIN) and controls in this study. sPlGF and sFlt-1 were detected in 44 preoperative patients with cervical cancer, 18 cases with CIN, and 20 controls by ELISA. It was found that both sPlGF and sFlt-1 were significantly increased in the cervical cancer group as compared with those in CIN and control groups. sPlGF presented a high diagnostic ability of cervical cancer, with a sensitivity of 61.36% and a specificity of 89.47%; and sFlt-1 with a sensitivity of 50.00% and a specificity of 92.11%. Importantly, the combined use of sPlGF and sFlt-1 could increase the diagnostic rate of cervical cancer, with a sensitivity of 70.45% and a specificity of 92.11%. These results indicated that both sPlGF and sFlt-1 in circulation can serve as possible valuable diagnostic biomarkers for cervical cancer, and the combined use of them can be more valuable to diagnose the patients with early cervical cancer.

Neoadjuvant Chemotherapy Alters Neuropilin-1, PlGF, and SNAI1 Expression Levels and Predicts Breast Cancer Patients Response

Circulating proteins hold a potential benefit as biomarkers for precision medicine. Previously, we showed that systemic levels of neuropilin-1 (NRP-1) and its associated molecules correlated with poor-prognosis breast cancer. To further identify the role of NRP-1 and its interacting molecules in correspondence with patients' response to neoadjuvant chemotherapy (NAC), we conducted a comparative study on blood and tissue samples collected from a cohort of locally advanced breast cancer patients, before and after neoadjuvant chemotherapy (NAC). From a panel of tested proteins and genes, we found that the levels of plasma NRP-1, placenta growth factor (PlGF) and immune cell expression of the transcription factor SNAI1 before and after NAC were significantly different. Paired t-test analysis of 22 locally advanced breast cancer patients showed that plasma NRP-1 levels were increased significantly (p = 0.018) post-NAC in patients with pathological partial response (pPR). Kaplan–Meier analysis indicated that patients who received NAC cycles and their excised tumors remained with high levels of NRP-1 had a lower overall survival compared with patients whose tissue NRP-1 decreased post-NAC (log-rank p = 0.049). In vitro validation of the former result showed an increase in the secreted and cellular NRP-1 levels in resistant MDA-MB-231 cells to the most common NAC regimen Adriyamicin/cyclophosphamide+Paclitaxel (AC+PAC). In addition, NRP-1 knockdown in MDA-MB-231 cells sensitized the cells to AC and more profoundly to PAC treatment and the cells sensitivity was proportional to the expressed levels of NRP-1. Unlike NRP-1, circulating PlGF was significantly increased (p = 0.014) in patients with a pathological complete response (pCR). SNAI1 expression in immune cells showed a significant increase (p = 0.018) in patients with pCR, consistent with its posited protective role. We conclude that increased plasma and tissue NRP-1 post-NAC correlate with pPR and shorter overall survival, respectively. These observations support the need to consider anti-NRP-1 as a potential targeted therapy for breast cancer patients who are identified with high NRP-1 levels. Meanwhile, the increase in both PlGF and SNAI1 in pCR patients potentially suggests their antitumorigenic role in breast cancer that paves the way for further mechanistic investigation to validate their role as potential predictive markers for pCR in breast cancer.

CYFRA 21-1 and Placental Growth Factor as Screening Markers for Endometriosis

Background

This study evaluated the performance of serum CYFRA 21-1 and placental growth factor (PIGF) as screening markers for endometriosis.

Material/Methods

In this prospective study included 81 female patients who underwent laparoscopy to treat benign ovarian tumors. Serum samples were obtained from all study patients before surgery. Serum marker levels, including CYFRA 21-1, PIGF, cancer antigen (CA)125, CA19-9, and human epididymis protein 4 (HE4) were measured using a fluorescence immunoassay technique.

Results

Forty of the patients were diagnosed with endometriosis (the study group) and 41 women were diagnosed with other benign ovarian tumors (the control group). Mean serum CYFRA 21-1 and PIGF levels were not different between these 2 groups (P=0.179 and P=0.865, respectively). Elevated serum CA125 levels (>35 U/mL) and lower CYFRA 21-1 levels (≤2.29 ng/mL) were more frequently observed in the endometriosis study group than in the control group (P<0.0001, and P=048, respectively). High serum PIGF levels (>14.2 pg/mL) were observed in both groups (P=0.226). Mean serum CA19-9 levels and HE4 levels, as well as the ROMA (risk of ovarian malignancy Algorithm) score were similar between the 2 groups. Sensitivity (95.0%) and negative predictive value (NPV) (80.0%) of CYFRA 21-1 for diagnosing endometriosis were higher than those of CA125 (sensitivity 67.5%, NPV 74.5%) and PIGF (sensitivity 20.0%, NPV 53.6%). However, the specificity (PIGF 90.2%, CA125 92.7%) and positive predictive value (PPV) (PIGF 66.7%, CA125 87.1%) of PIGF and CA125 for diagnosing endometriosis were higher than those of CYFRA 21-1 (specificity 19.5%, PPV 53.5%).

Conclusions

CYFRA 21-1 and PIGF may be promising markers to identify patients with and without ovarian endometriosis.

Association of Oral Cavity and Oropharyngeal Cancer Biomarkers in Surgical Drain Fluid With Patient Outcomes

Importance

Survival rates for head and neck cancer have been relatively stable for several decades. Individualized prognostic indicators are needed to identify patients at risk for poorer outcomes.

Objective

To determine whether biomarker levels in surgical drain fluid of patients with head and neck cancer are associated with poor cancer outcomes.

Design, Setting, and Participants

This prospective cohort study enrolled patients with squamous cell carcinoma (SCC) of the oral cavity and oropharynx who required surgical treatment from April 1, 2011, to February 1, 2016, at a tertiary or academic care center. Twenty patients, including 14 with stage IV disease, had complete specimen collection. Differences in cytokine and MMP levels by disease outcomes were evaluated.

Interventions

Patients underwent surgical treatment with drain placement as dictated by the standard of care. Drain fluid samples were collected every 8 hours postoperatively until drains were removed because of clinical criteria. Levels of cytokines and matrix metalloproteinases (MMPs) were measured using electrochemiluminescent, patterned array, multiplex technology.

Main Outcomes and Measures

The primary clinical outcome measures were survival outcome and recurrence. The biomarkers measured included the cytokines basic fibroblastic growth factor, vascular endothelial growth factor isoform A, soluble fms-like tyrosine kinase-1 (sFlt-1), and placental growth factor (PIGF) and MMP-1, MMP-3, and MMP-9. Other clinical and pathologic cancer characteristics were recorded.

Results

In this cohort of 20 patients with SCC (15 men and 5 women; mean [SD] age, 63.5 [9.9] years), a significant association with recurrence was found for levels of MMP-1 (relative difference between groups, 2.78; 95% CI, 1.23-6.29), MMP-3 (relative difference between groups, 5.29; 95% CI, 2.14-13.05), and sFlt-1 (relative difference between groups, 3.75; 95% CI, 1.84-7.65). No biomarkers were associated with disease outcome. Vascular endothelial growth factor isoform A was associated with nodal metastasis (relative difference between groups, 1.98; 95% CI, 1.12-3.51), and basic fibroblastic growth factor was associated with lymphovascular invasion (relative difference between groups, 1.74; 95% CI, 1.02-2.97).

Conclusions and Relevance

In this pilot sample of patients with SCC of the oral cavity and oropharynx, MMP-1, MMP-3, and sFlt-1 levels in wound fluid were associated with poor clinical cancer outcomes in the form of recurrence. This finding is consistent with the literature of tumor microenvironment in saliva, serum, and tumor tissue biomarkers. To our knowledge, this report is the first of such findings in surgical drain fluid, an easily accessible means of cytokine measurement. Measurement of these biomarkers in surgical fluid potentially represents a novel means of assessing cancer prognosis in this population.

Evaluating tumour after care in oral squamous cell carcinoma: Insights into patients' health related quality of life

INTRODUCTION

Tumour aftercare (tac) is an essential tool in oncology. The main aim of these follow ups is to diagnose recurrence and second tumours from the beginning. Tac appointments can create a special environment for patients' further concerns. The purpose of the current study was to evaluate tac of patients diagnosed with OSCC and to investigate their health related quality of life (hrql).

MATERIAL AND METHODS

A German questionnaire was created by two maxillo-facial surgeons with several years of tac experience. It was handed out to 100 German-speaking OSCC patients during tac. Results were statistically evaluated with SPSS (SPSS version 21.0; SPSS, IBM; Chicago, IL, USA). The inclusion criterion was that diagnosis and surgery were performed at our department and that the patients attended our tac regularly.

RESULTS

Side effects such as difficulties in speaking and swallowing were evaluated as being significantly higher in cases who were administered adjuvant radiochemotherapy (art) compared with the surgical therapy group (stg) (p = 0.03). Anxiety occurred in 80% of all female patients (p = 0.02), 90% of them with a high psychological strain because of the cancer diagnosis (p = 0.04).

DISCUSSION

To date, tac is a rare topic in literature. Moreover, only a few trials have focused on hrql in OSCC. A main result of the current study is that during tac, OSCC patients should be regularly questioned about their symptoms and mental state. Further, the need of the majority of OSCC patients for coping therapies can concomitantly be evaluated.

CONCLUSION

The evaluation of tac is of high relevance. The results of the current study have encouraged us to establish this questionnaire as a routine tool in our tac.

Diagnostic accuracy of serum biomarkers for head and neck cancer: A systematic review and meta-analysis

Serum biomarkers could be helpful to characterize head and neck squamous cell carcinoma (HNSCC). Thus, the purpose of this systematic review and meta-analysis was to determine the diagnostic capability of serum biomarkers in the assessment of HNSCC patients. Studies were gathered by searching LILACS, PubMed, Science Direct, Scopus and Web of Science up to April 10th, 2015. Studies that focused on serum biomarkers in the diagnosis of HNSCC compared with controls were considered. Sixty-five studies were identified, and the sample size included 9098 subjects. Combined biomarkers demonstrated improved accuracy than those tested individually. Therefore, 12.8% of single and 34.3% of combined indicated that serum biomarkers discriminate patients with HNSCC from controls. The combined biomarkers with better diagnostic capability included Epidermal growth factor receptor (EGFR)+Cyclin D1 and squamous cell cancer-associated antigen (SCCA)+EGFR+Cyclin D1. Beta2-microglobin may also be a promising single biomarker for future studies. Serum biomarkers can be potentially useful in the diagnosis of HNSCC. However, further research is required to validate these biomarkers.

Performance of Circulating Placental Growth Factor as A Screening Marker for Diagnosis of Ovarian Endometriosis: A Pilot Study

Background

The aim of this study is to compare the circulating placental growth factor (PlGF) concentration in women with and without endometrioma to verify the performance of this marker to diagnose the disease.

Materials and Methods

In this case-control study, thirteen women with histological diagnosis of ovarian endometriosis were compared with women without endometriosis disease. PlGF plasma levels of endometriotic patients and controls were investigated using a fluorescence immunoassay technique.

Results

PlGF showed a direct correlation with body mass index (BMI) only in the control group (P=0.013). After adjustment for BMI values, PlGF median value in endometriosis group (14.7 pg/mL) resulted higher than in control group (13.8 pg/ mL, P=0.004).

Conclusion

PlGF is a promising peripheral blood marker that can discriminate between patients with and without ovarian endometriosis.

Evaluation of a biomarker based blood test for monitoring surgical resection of oral squamous cell carcinomas

INTRODUCTION

The potential use of determination of biomarkers in blood for the monitoring of surgical removal of oral squamous cell carcinomas (OSCC) was evaluated using the epitope detection in monocytes (EDIM) technology.

MATERIALS AND METHODS

In tumor specimen, elevated Apo10 and transketolase-like 1 (TKTL1) expression was analyzed by immunohistochemistry. Apo10 and TKTL1 biomarkers have been used prospectively for EDIM blood test in patients with primary and/or recurrent OSCC (n = 92) before surgery and after curative tumor resection (n = 45).

RESULTS

There were highly significant (p < 0.0001) correlations found between EDIM blood scores and the tissue expression of both biomarkers measured by immunohistochemistry (Apo10: n = 89/92, 97%; TKTL1: n = 90/92, 98%). EDIMApo10 and EDIM-TKTL1 scores were positive in 92% (EDIM-Apo10: n = 85/92) and 93% (EDIM-TKTL1: n = 86/92), respectively, in patients with OSCC before surgery. The combined score EDIM-Apo10/EDIM-TKTL1 increased significantly the detection rate of tumors to 97% (n = 89/92). After surgery, the EDIM-TKTL1 and EDIMApo10 scores significantly decreased in 75.6 and 86.7% of the patients (p < 0.0001), respectively, in the aftercare.

CONCLUSIONS

The correlation of TKTL1 and Apo10 immunohistochemistry with the blood test results indicates that the EDIM blood test could serve as a non-invasive diagnostic tool (liquid biopsy) to assess surgical removal of OSCC by determination of two biomarkers.

CLINICAL RELEVANCE

This is the first study that has been demonstrated a reliable and successful monitoring of OSCC cancer patients by a blood test. The specific and significant decrease of EDIM-TKTL1 and EDIM-Apo10 scores after surgery could serve as a new tool for monitoring surgical removal of OSCC.

Placental growth factor supports neuroendocrine tumor growth and predicts disease prognosis in patients

Placental growth factor (PlGF), a VEGF-homolog implicated in tumor angiogenesis and adaptation to antiangiogenic therapy, is emerging as candidate target in malignancies. Here, we addressed the expression, function, and prognostic value of PlGF in neuroendocrine tumors (NETs). PlGF was determined in NET patients' sera collected retrospectively (n=88) and prospectively (n=87) using Roche-Elecsys and correlated with clinicopathological data. Tumoral PlGF was evaluated by immunohistochemistry, effects of PlGF on proliferation and migration in vitro were assessed using different NET cell lines and effects on tumor growth in vivo in orthotopic xenografts. Circulating and tumoral PlGF was elevated in patients with pancreatic NETs (pNETs) compared with control sera and respective healthy tissue. De novo PlGF expression occurred primarily in the tumor stroma, suggesting paracrine stimulatory circuits. Indeed, PlGF enhanced NET proliferation and migration in vitro and, conversely, neutralizing antibodies to PlGF reduced tumor growth in vivo. Elevated circulating PlGF levels in NET patients correlated with advanced tumor grading and were associated with reduced tumor-related survival in pNETs. Subsequent determinations confirmed and extended our observation of elevated PlGF levels in a prospective cohort of grade 1 and grade 2 pNETs (n=30) and intestinal NETs (n=57). In low-grade pNETs, normal circulating PlGF levels were associated with better survival. In intestinal NETs, circulating PlGF above median emerged as an independent prognostic factor for shorter time-to-progression in multivariate analyses. These data assign to PlGF a novel function in the pathobiology of NETs and propose PlGF as a prognostic parameter and therapeutic target.

The recurrence and survival of oral squamous cell carcinoma: a report of 275 cases

Oral squamous cell carcinoma (OSCC) is a common malignant tumor of the head and neck, and recurrence is an important prognostic factor in patients with OSCC. We explored the factors associated with recurrence of OSCC and analyzed the survival of patients after recurrence. Clinicopathologic and follow-up data of 275 patients with OSCC treated by surgery in the Cancer Institute and Hospital of Tianjin Medical University between 2002 and 2006 were analyzed. Recurrence factors were analyzed with Chi-square or Fisher's exact test and multivariate analysis. The prognosis of patients after recurrence was analyzed with the Kaplan-Meier method and log-rank test. The recurrence rate was 32.7%. The recurrence time ranged from 2 to 96 months, with a median of 14 months. Univariate analysis showed that T stage, degree of differentiation, pN stage, flap application, resection margin, and lymphovascular invasion were factors of recurrence (P < 0.05). Multivariate analysis showed that T stage, degree of differentiation, and pN stage were independent factors of recurrence (P < 0.001). The differences in gender, age, tumor site, region of lymph node metastasis, and perineural invasion between the recurrence and non-recurrence groups were not significant (P > 0.05). Kaplan-Meier and log-rank tests showed that the 2- and 5-year survival rates were significantly lower in the recurrence group than in non-recurrence group (67.6% vs. 88.0%, 31.8% vs. 79.9%, P < 0.001). Therefore, to improve prognosis, we recommend extended local excision, flap, radical neck dissection, and adjuvant chemoradiotherapy for patients more likely to undergo recurrence.

The metastatic niche and stromal progression

The tumor stroma is comprised of extracellular matrix, non-malignant cells, and the signaling molecules they produce. It is an integral and vital component of primary tumors that together with the underlying genetic defects in the tumor cells determines the growth characteristics, morphology, and invasiveness of the tumor. In parallel to continuing genetic changes in the tumor cells themselves, the tumor stroma progressively evolves during primary tumor development. Cancer cells that disseminate from primary tumors are dependent on this stromal microenvironment, and therefore the microenvironment they encounter at secondary sites determines their fate. For those cells that survive at these sites, stromal progression can serve to re-establish a supportive tumor stroma, fostering the outgrowth of the cells as metastases. Formation of a metastatic niche that supports the survival and growth of disseminated tumor cells is a key feature of this stromal progression. The endogenous organ microenvironment can provide components of the metastatic niche. In addition, microenvironmental changes in organs prior to receipt of disseminated tumor cells can be induced by factors secreted systemically by primary tumors, causing the formation of pre-metastatic niches. Further maturation of metastatic niches can be responsible for the re-activation of dormant disseminated tumor cells many years after removal of the primary tumor. The concept of the metastatic niche and stromal progression has profound consequences for our understanding of metastatic disease, and promises to open up new strategies for the diagnosis, prognostic evaluation, and therapy of cancer.

Arecoline-stimulated placenta growth factor production in gingival epithelial cells: modulation by curcumin

OBJECTIVE

Placenta growth factor (PlGF) is associated with the progression and prognosis of oral cancer.

MATERIALS AND METHODS

This study used ELISA, quantitative polymerase chain reaction, and Western blotting to study the arecoline-stimulated (PlGF) protein or mRNA expression in human gingival epithelial S-G cells.

RESULTS

Arecoline, a major areca nut alkaloid and an oral carcinogen, could stimulate PlGF protein synthesis in S-G cells in a dose- and time-dependent manner. The levels of PlGF protein secretion increased about 3.1- and 3.8-fold after 24-h exposure to 0.4 and 0.8 mM arecoline, respectively. Pretreatment with antioxidant N-acetyl-l-cysteine (NAC) and ERK inhibitor PD98059, but not NF-κB inhibitor Bay 11-7082, JNK inhibitor SP600125, p38 MAPK inhibitor SB203580, and PI3-K inhibitor LY294002, significantly reduced arecoline-induced PlGF protein synthesis. ELISA analyses demonstrated that NAC and PD98059 reduced about 43% and 38% of the arecoline-induced PlGF protein secretion, respectively. However, combined treatment with NAC and PD98059 did not show additive effect. Moreover, 10 μM curcumin and 4 mM NAC significantly inhibited arecoline-induced ERK activation. Furthermore, 10 μM curcumin completely blocked arecoline-induced PlGF mRNA expression.

CONCLUSION

Arecoline-induced PlGF synthesis is probably mediated by reactive oxygen species/ERK pathways, and curcumin may be an useful agent in controlling oral carcinogenesis.