Effects of antioxidant co-supplementation therapy on spermatogenesis dysfunction in relation to the basal oxidation-reduction potential levels in spermatozoa: A pilot study.

Purpose: In this pilot study, the authors compared the effects of antioxidant co-supplementation therapy and methylcobalamin therapy in patients with impaired semen quality. Methods: Eighty-four subjects who visited male infertility clinics and showed abnormal semen test results were randomly subjected to one of the two therapies: antioxidant co-supplementation therapy with vitamin C, vitamin E, coenzyme Q10, and flaxseed oil or methylcobalamin therapy. The oxidation-reduction potential (ORP) and 8-hydroxy-2'-deoxyguanosine levels were used as indicators of oxidative stress levels in semen. Semen analysis was also performed. Results: The authors obtained results from 67 patients who had completed 3 months of treatment. Neither antioxidant co-supplementation therapy nor methylcobalamin therapy changed the semen parameters significantly (except for the sperm concentration, which was increased by the latter therapy). When the pre-treatment ORP value in semen was higher than the cutoff value, both therapies significantly increased the sperm concentration. The 8-hydroxy-2'-deoxyguanosine level did not yield any meaningful predictive value with regard to increased sperm concentrations. Conclusions: Both antioxidant co-supplementation therapy and methylcobalamin therapy increased the sperm concentration in patients with impaired semen quality when the basal ORP levels in their semen were elevated.

Androgen receptor mRNA expression is a predictor for recurrence-free survival in non-muscle invasive bladder cancer.

BACKGROUND: Non-muscular invasive bladder cancer (NMIBC) has a high risk of recurrence. As androgen receptor (AR) reportedly affects bladder cancer, we assessed the correlation between NMIBC recurrence and tumor AR expression in Japanese patients. METHODS: We retrospectively reviewed 53 specimens of non-metastatic NMIBC, with recurrence-free survival (RFS) as the primary endpoint. We used real-time quantitative polymerase chain reaction to quantify AR mRNA expression. Kaplan-Meier product-limit estimators were used to assess RFS distribution, log-rank tests to analyze differences in RFS between high- and low-risk groups; and multivariate analyses of AR mRNA expression and other clinicopathological factors to predict independent factors for RFS. RESULTS: The high AR mRNA-expressing group (n = 43) tended to have a longer median RFS (not reached) than did the low-AR group (n = 10; 9.04 months; P = 0.112). Multivariate analysis showed female sex (hazard ratio [HR]: 7.360, 95% CI: 1.649-32.856, P = 0.009), tumor size ≥3 cm (HR: 23.697, 95% CI: 4.383-128.117, P < 0.001) and low AR mRNA expression (HR: 0.202, 95% CI: 0.048-0.841, P = 0.028) to be independent predictors of shorter RFS. CONCLUSION: Our study showed that low AR mRNA expression level is an independent risk factor for RFS in Japanese patients with NMIBC. Further studies are necessary but AR expression might be a new indicator of recurrence of NMIBC.

Expression of PD-L1 and CTLA-4 in female urethral carcinoma.

INTRODUCTION: Although the tumors are often easily detected, a considerable number of patients with female urethral carcinoma are diagnosed in an advance stage. Thus, no evidence-based therapeutic approach has been established. We herein report our experience in the treatment of three female patients with urethral carcinoma. We also examined the expression of PD-L1 and CTLA-4. CASE PRESENTATION: Three female patients pathologically diagnosed with urethral carcinoma, including urothelial carcinoma, squamous cell carcinoma, and adenocarcinoma, between 2013 and 2017 were analyzed in this study. Two patients underwent urethrectomy with cystostomy. Immunohistochemistry was performed to assess the levels of PD-L1 and CTLA-4 expression in patients with urethral carcinoma. Eleven control cases of urethral carcinoma tissue were also stained. CONCLUSION: This study revealed the expression of PD-L1 and CTLA-4 in female urethral carcinomas.

PD-1 and PD-L1 are more highly expressed in high-grade bladder cancer than in low-grade cases: PD-L1 might function as a mediator of stage progression in bladder cancer.

BACKGROUND: Bladder cancers have been characterized as a tumor group in which the immunological response is relatively well preserved. Programmed death ligand 1 (PD-L1, B7-H1, CD274) has been shown to be expressed in several malignancies, including bladder cancer. However, the clinicopathological impact of this biomarker has not yet been established. In the present study, a quantitative real-time polymerase chain reaction (qPCR) was performed using paired normal and cancerous bladder cancer tissue to investigate PD-1/PD-L1 gene expression. METHODS: We examined the mRNA expression of PD-1/PD-L1 by a qPCR using 58 pairs of normal and cancerous human bladder tissue specimens. We also examined the correlation with the expressions of the STAT1 and NFAT genes, which are thought to be upstream and downstream of the PD-L1 pathway, respectively. RESULTS: There were no significant differences between normal and cancerous tissue in the expression of the PD-1 and PD-L1 genes (p = 0.724 and p = 0.102, respectively). However, PD-1 and PD-L1 were both more highly expressed in high-grade bladder cancer than in low-grade bladder cancer (p < 0.050 and p < 0.010). PD-L1 was positively correlated with the expressions of both the STAT1 (r = 0.681, p < 0.001) and the NFATc1 genes (r = 0.444. p < 0.001). CONCLUSIONS: PD-1 and PD-L1 might be a new biomarker that correlates with the pathological grade of bladder cancer. PD-L1 might function as a mediator of stage progression in bladder cancer and STAT1-NFAT pathway might associate this function.

Oxidative stress marker 8-hydroxyguanosine is more highly expressed in prostate cancer than in benign prostatic hyperplasia.

Oxidative stress is a primary cause of vascular endothelial damage. In the prostate, ischemia increases the levels of reactive oxygen species, growth factors and cytokines, and induces the development of angiogenesis, which results in cancer progression. The expression levels of an oxidative stress marker, 8-hydroxyguanosine (8-OHdG), were compared between prostate cancer and non-neoplastic prostate tissues. A prostate tissue microarray composed of 10 cases of prostatic adenocarcinoma and 70 cases of benign prostatic hyperplasia was immunohistochemically stained for 8-OHdG. All cases expressed 8-OHdG. The levels of 8-OHdG expression in prostatic cancer (30.0% moderate and 70.0% strong) were significantly higher than those in benign prostatic hyperplasia (71.4% moderate and 28.6% strong; (p<0.01). Notably, 8-OHdG is expressed more highly in prostate cancer tissues in comparison to benign prostate tissues.

Chemopreventive effects of angiotensin II receptor type 2 agonist on prostate carcinogenesis by the down-regulation of the androgen receptor.

We recently reported that angiotensin II receptor blockers (ARBs) have chemopreventive and chemotherapeutic potential against prostate cancer via the reduction of androgen receptor (AR) expression. In this study, we investigated the effects of the angiotensin II receptor type 2 (AT2R) agonist Compound 21 (C21), which is expected to play similar roles to an ARB, on prostate carcinogenesis using the transgenic rat for adenocarcinoma of prostate (TRAP) model previously established in our laboratory. In vitro analyses of the cell growth, Western blotting and reporter gene assays were performed using LNCaP cells. TRAP rats at 6 weeks of age were randomly divided into 3 groups of 12 animals each and treated with C21 at 1 or 2 mg/kg/day in drinking water for 12 weeks. C21 reduced the proliferation activity of prostate cancer cells and down-regulated the PSA promoter activity and the AR protein expression. We discovered that C21 inhibited the progression of prostate carcinogenesis in TRAP rats and decreased the incidence of adenocarcinoma in the lateral prostate. A significant increase in the apoptotic index with activation of caspase 3 and 7 were observed by immunohistochemistry and Western blotting analyses. C21 also down-regulated the expression of AR significantly in TRAP rat prostate. C21 decreased the expression of AR and reduced the proliferation activity effectively in prostate cancer cells and TRAP rat prostate. These findings suggest that AT2R agonist may be a candidate novel chemopreventive agent against human prostate cancer.

[Corrigendum] Antitumor effects of IDN5109 on head and neck squamous cell carcinoma.

Oncol Rep 15: [Related article:] 329­334, 2006; DOI: 10.3892/or.15.2.329 After the publication of the article, the authors noted that the relevance of the findings reported in this article on IDN5109 inhibition of growth of head and neck squamous cell carcinoma (HNSCC) is now in question. To examine the antitumor effect of IDN5109, this study was conducted using YCU-H891 and KCC-MS871 cell lines that the authors believed to be HNSCC cell lines. Because different human leukocyte antigen (HLA) was detected in 2 cell lines (KCC-TCM901 and KCC-T873) which were derived from the same patient in an experiment after publication, 16 cell lines established in our institution were analyzed by short tandem repeat (STR) analysis. STR analysis revealed that genotype of KCC-TCM901, YCU-H891 and KCC-MS871 was identical to that of HeLa cells, and that genotype of YCU-T891 was identical to that of YCU-L891, which was considered to be cross-contamination.

[Corrigendum] Antitumor effects of ZD6474 on head and neck squamous cell carcinoma.

Oncol Rep 17: [Related article:] 289­295, 2007; DOI: 10.3892/or.17.2.289 After the publication of the article, the authors noted that the relevance of the findings reported in this article on ZD6474 inhibition of growth of head and neck squamous cell carcinoma (HNSCC) is now in question. To examine the antitumor effect of ZD6474 in vitro and in vivo, this study was conducted using YCU-H891 cell line that the authors believed to be HNSCC cell line. Because different human leukocyte antigen (HLA) was detected in 2 cell lines (KCC-TCM901 and KCC-T873) which were derived from the same patient in an experiment after publication, 16 cell lines established in our institution were analyzed by short tandem repeat (STR) analysis. STR analysis revealed that genotype of KCC-TCM901, YCU-H891 and KCC-MS871 was identical to that of HeLa cells, and that genotype of YCU-T891 was identical to that of YCU-L891, which was considered to be cross-contamination.

Epidermal growth factor receptor tyrosine kinase inhibition up-regulates interleukin-6 in cancer cells and induces subsequent development of interstitial pneumonia.

Acute interstitial pneumonia is one of serious side effects of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) treatment, while it often has significant clinical benefit in cancer patients. Therefore, it is necessary to clarify underlying mechanisms for the development of the adverse effects by EGFR-TKI. In the present study, we attempted to determine how EGFR-TKI treatment in cancer cells induced interstitial pneumonia. The growth of tongue cancer HSC-3 and lung cancer A549 cell lines treated with EGFR-TKI was assessed by MTT assay. Cytokines and growth factors in conditioned medium (CM) obtained from EGFR-TKI-treated cancer cells were analyzed using cytokine membrane array and ELISA. Interleukin-6 (IL-6) promoter activity was measured by luciferase assay. We found that EGFR-TKI treatment significantly decreased the cell viability yet increased expression levels of IL-6 protein and mRNA, IL-6 secretion, and IL-6 transcriptional activity in these lines. In addition, using the co-culture model and IL-6 treatment was found to increase the expression of collagen and α-actin, which were markers for fibrosis, in lung fibroblast cells. These results suggest that up-regulated IL-6 plays an important role in the development of EGFR-TKI-induced interstitial fibroblastic proliferation. Therefore, blocking of IL-6 signaling could be beneficial to cancer patients undergoing EGFR-TKI treatment for reducing the risk of its unfavorable effects.

Examination of the optimal condition on the in vitro sensitivity to telomelysin in head and neck cancer cell lines.

OBJECTIVE: Telomelysin (OBP-301) is a telomerase-specific replication-competent adenovirus with a human telomerase reverse transcriptase (hTERT) promoter. Telomelysin has a strong antitumor effect on a variety of cancers, including head and neck squamous cell carcinoma (HNSCC), and combining telomelysin treatment with paclitaxel or cisplatin enhances the antitumor effect on HNSCC. In the present study, we investigated the relationship between the antitumor activity of telomelysin and tumor cell doubling time(DT), S-phase fraction, and E1A expression. We also investigated whether the antitumor effects of OBP-301-resistant tumor cells are enhanced by cisplatin, paclitaxel, or streptolysin O. METHODS: The tumor cell DT of 17 human HNSCC cell lines was examined. Antitumor activities of telomelysin (OBP-301) for each HNSCC cell line were examined by MTT assay. Cell cycle analysis was conducted by flowcytometry. E1A gene expressions after infection with telomelysin, hTERT, CAR (Cocksackie Adenovirus Receptor), and c-Myc were examined by quantitative PCR, and E1A expressions were examined again after pretreatment with cisplatin, paclitaxel, or streptolysin O. Correlations were analyzed by Spearman's correlation coefficient. RESULTS: There was a significant relationship between telomelysin sensitivity and DT, S-phase fraction and early E1A expression, and pretreatment with cisplatin, paclitaxel, and streptolysin O increased infectivity of telomelysin-resistant HNSCC cell lines. CONCLUSION: These findings are useful for advancing clinical trials, and suggest that adjuvant telomelysin treatment would be effective even in telomelysin-resistant HNSCC cell lines.

Antitumor effects of lapatinib (GW572016), a dual inhibitor of EGFR and HER-2, in combination with cisplatin or paclitaxel on head and neck squamous cell carcinoma.

The epidermal growth factor receptor (EGFR) and a related family member, HER-2, are often overexpressed simultaneously in patients with a variety of malignant tumors, and the combination may cooperatively promote cancer cell growth and survival. Heterodimerization of EGFR and HER-2 has been known to create intense proliferative signals. Lapatinib (GW572016) is a small molecule that is administrated orally and functions as a reversible inhibitor of both EGFR and HER-2 tyrosine kinases. In the present study, we evaluated the antitumor effect of lapatinib on head and neck squamous cell carcinoma (HNSCC) cell lines in vitro and in vivo. In vivo we examined the antitumor effects of combined treatment with lapatinib and either cisplatin or paclitaxel. In vitro lapatinib displayed antiproliferative effects on HNSCC cells. The IC50 of lapatinib ranged between 13.6 and 60.2 microM after 24-h exposure to lapatinib. A correlation was not observed between results of in vitro proliferation assays for lapatinib and the expression of EGFR or HER-2. In vivo lapatinib displayed antitumor activity, and induced apoptosis in nude mice bearing an established xenograft of YCU-H891 cells. Lapatinib did not significantly inhibit angiogenesis. Combination treatment of lapatinib with cisplatin or paclitaxel enhanced antitumor activity mainly by inducing apoptosis. Inhibition of antiangiogenesis was observed only for combination treatment of lapatinib with paclitaxel (compared to vehicle control). These results suggest that: i) lapatinib has antitumor effects in vitro and in vivo; ii) lapatinib may be more effective in combination with cisplatin or paclitaxel; and iii) lapatinib might provide useful clinical benefits to HNSCC patients.

Antitumor effects of telomelysin in combination with paclitaxel or cisplatin on head and neck squamous cell carcinoma.

Telomelysin (OBP-301) is a telomerase-specific replication-component adenovirus. Telomelysin has a human telomerase reverse transcriptase (hTERT) promoter element which efficiently kills human cancer cells, but not normal cells. The present study investigated the correlation between the antitumor effect of telomelysin and mRNA expression of hTERT and coxsackievirus and adenovirus receptor (CAR) in head and neck squamous cell carcinoma (HNSCC) in vitro and whether telomelysin enhances the antitumor effect of paclitaxel or cisplatin, in vivo using a HNSCC xenograft model. We also determined the optimal order for combining telomelysin treatment and chemotherapy as concurrent treatment, telomelysin treatment first and chemotherapy later, chemotherapy first and telomelysin treatment later for achieving the best anticancer effect. The mRNA expression of hTERT and CAR genes was examined by quantitative RT-PCR in 17 HNSCC cell lines. There was no significant correlation between the growth inhibition of telomelysin (ID50 for day 3, 5 and 7) in vitro and mRNA expression levels of hTERT and CAR. Regarding the correlation between CAR expression and telomelysin ID50 for day 3, all cell lines that showed a relative amount of CAR/beta-actin mRNA >0.4 had a low telomelysin ID50. This may indicate that CAR expression contributes to the efficacy of adenovirus infection and the antitumor activity of telomelysin in early stages of treatment. In our in vivo study, combining telomelysin and paclitaxel had an additive effect regardless of treatment order. On the other hand, combining telomelysin and cisplatin had additive effect only when cisplatin treatment preceded telomelysin treatment. These results suggest that paclitaxel is considered innocuous for replication of telomelysin, however cisplatin may influence replication of telomelysin.

Heterozygous mutation (G/G→G/A) at nt 2607 of the EGFR gene is closely associated with increases in EGFR copy number and mRNA half life, but impaired EGFR protein synthesis in squamous cell carcinomas of the head and neck - implication for gefitinib efficacy.

Gefitinib (ZD1839, Iressa(®)) is an orally active agent that inhibits the tyrosine kinase activity of epidermal growth factor receptor (EGFR). Gefitinib has shown a high efficacy in patients with non-small cell lung carcinoma and specific mutations in the ATP-binding pocket of EGFR. These mutations, however, are extremely rare in squamous cell carcinomas of the head and neck (SCCHN). We previously showed that SCCHN cell lines with a heterozygous mutation (G/G→G/A) at nucleotide 2607 of EGFR are more sensitive to gefitinib than wild-type cell lines (79.5% higher IC(50)). To determine the relationship between the G/G and G/A genotypes, we assessed the EGFR gene copy number and the EGFR mRNA half-life in 16 different SCCHN cell lines. Fluorescence in situ hybridization showed that the EGFR copy number was significantly higher in the nine 2607G/A cell lines than in the seven 2607G/G cell lines (3.59±2.14 vs. 1.58±0.32 copies, a 2.27-fold difference). Similarly, the half life of EGFR mRNA was 2.24-fold higher in cell lines with the 2607G/A genotype than in those with wild-type. By contrast, the EGFR protein levels were inversely correlated with mRNA abundance. These findings suggest that sensitivity to gefitinib of cells with the heterozygous mutation (2607G/G→G/A) was closely associated with gene amplification, the prolongation of mRNA half-life and a decrease in EGFR protein.

Restoration of BRAK / CXCL14 gene expression by gefitinib is associated with antitumor efficacy of the drug in head and neck squamous cell carcinoma.

Clinical efficacy of gefitinib (ZD1839, Iressa), which is an inhibitor specific for epidermal growth factor (EGF) receptor tyrosine kinase, has been shown in non-small-cell lung carcinoma patients with EGF receptor mutations, so these mutations are useful marker(s) to find a responder for the drug. Recent studies have shown that the EGF receptor gene mutation is rare in squamous cell carcinoma in the esophageal and head and neck regions. We previously reported that the expression of the chemokine BRAK/CXCL14 in head and neck squamous cell carcinoma (HNSCC) cells was down-regulated by EGF treatment, and that forced expression of BRAK in tumor cells decreased the tumorigenicity of the cells in xenografts. Thus, we investigated the relationship between restoration of BRAK expression by gefitinib and the efficacy of the drug for tumor suppression. We found that EGF down-regulated BRAK expression through the MEK-extracellular signal regulated kinase pathway and that this down-regulated expression was restored by gefitinib in vitro. Oral administration of gefitinib significantly (P < 0.001) reduced tumor growth of xenografts of three HNSCC cell lines (HSC-2, HSC-3, and HSC-4), in female athymic nude mice, accompanied by an increase in BRAK expression specifically in tumor tissue. This tumor-suppressing effect of the drug was not observed in the case of BRAK non-expressing cells. Furthermore introduction of BRAK shRNA vector reduced both the expression levels of BRAK in HSC-3 cells and the antitumor efficacy of gefitinib in vivo. Our data showing an inverse relationship between BRAK expression levels in tumor cells and the tumor growth rate indicate that the gefitinib-induced increase in BRAK expression is beneficial for tumor suppression in vivo.

Anti-tumor effects of telomelysin for head and neck squamous cell carcinoma.

Telomelysin is a telomerase-specific replication-competent adenovirus with telomerase reverse transcriptase (hTERT) promoter, which has shown strong anti-tumor effects on a variety of human cancer cells. Human head and neck squamous cell carcinoma (HNSCC) cell lines and a murine HNSCC (NR-S1) model were used to investigate whether telomelysin (OBP-301) had a therapeutic efficacy for HNSCC. We examined the cell killing effects of telomelysin and the induction of tumor cell apoptosis by telomelysin in vitro. Based on these data, we examined whether telomelysin therapy produced therapeutic benefits in vivo. The results demonstrated that the treatment of telomelysin led to significant tumor regression on the side with subcutaneous NR-S1 tumor. We first confirmed the direct anti-tumor effect of intratumoral telomelysin injections in a murine HNSCC model. Further analyses of the augmented anti-tumor effects revealed that telomelysin increased the source of tumor antigens for immune cells, resulting in the induction of CD4+ and CD8+ T cells responsible for the in vivo tumor regression of treated and untreated tumors. Subsequently, an elevated IFN-gamma production of spleen cells was observed in mice treated with telomelysin. These results raise the possibility that telomelysin enhances the immune response in addition to its direct tumor cell killing activity. These findings suggest that telomelysin is a potent agent for the treatment of HNSCC patients with multiple metastases.

Correlation between FDG-PET findings and GLUT1 expression in salivary gland pleomorphic adenomas.

OBJECTIVE: One reason for the difficulty in accurate preoperative pathological diagnosis of major salivary gland tumors with fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) is the tendency of pleomorphic adenomas to have a high, standardized uptake value (SUV). The expression of glucose transporter 1 (GLUT1) and the quantity of GLUT1 messenger RNA (mRNA) were analyzed in specimens of pleomorphic adenoma to identify whether GLUT1 is responsible for the increased glucose uptake in FDG-PET examinations of these tumors. METHODS: Eighty salivary gland tumors resected at Yokohama City University Hospital were retrospectively investigated. FDG-PET was performed prior to surgery. PET images were evaluated by two experienced radiologists. GLUT1 was immunohistochemically stained, and GLUT1 mRNA density was quantified using real-time polymerase chain reaction in 10 of 40 pleomorphic adenomas. RESULTS: The pleomorphic adenomas stained positively for GLUT1, and there was significant correlation between the GLUT1 index and the SUV in FDG-PET. CONCLUSIONS: GLUT1 is expressed in salivary gland pleomorphic adenomas. Furthermore, the GLUT1 index shows significant correlation with the SUV of FDGPET. This result suggests that GLUT1 plays an important role in increasing FDG uptake in salivary gland pleomorphic adenomas.

Antitumor effect of gefitinib on head and neck squamous cell carcinoma enhanced by trastuzumab.

The overexpression of EGFR and/or HER-2 is associated with tumor cell resistance to chemotherapy, radiotherapy, disease progression and poor prognosis in patients with a variety of malignant tumors. Treatment combining the EGFR-targeting drug, gefitinib (ZD1839, Iressa) with the HER-2-targeting drug, trastuzumab (Herceptin) has been reported to improve therapeutic efficacy in patients with breast cancer. The purpose of this study was to examine the antitumor effect of this combination on head and neck squamous cell carcinoma (HNSCC) in vitro. Cell proliferation was inhibited significantly in two cell lines. Although IC50 of gefitinib alone against some cell lines was not reached, it was achieved after being combined with trastuzumab. Furthermore, IC50 was lower for the combination than for gefitinib alone in several cell lines. These results suggest that the combination may improve efficacy against HNSCC.

Angiotensin II induces oxidative stress in prostate cancer.

Angiotensin II has been shown to be a cytokine especially acting as a growth factor. A local renin-angiotensin system has been identified in the prostate gland, and the physiologic function of angiotensin II seems to be similar in prostate cancer, as we previously reported. In the present study, we explored the biological role of angiotensin II in oxidative stress of prostate cancer cells. Activated Akt was determined, and the expression of oxidative stress-related proteins (p47phox, manganese superoxide dismutase 2, glutathione peroxidase) was examined by Western blotting in LNCaP cells, which were stimulated with angiotensin II and/or an angiotensin II receptor type 1 blocker, candesartan. To examine DNA damage induced by angiotensin II, 8-hydroxy-2'-deoxyguanosine was determined, and Western blots were analyzed to detect checkpoint proteins including p53, Chk2, and cdc2. Immunocytochemical studies of inducible nitric oxide synthase and superoxide anion radical (O(2)(-)) were done in LNCaP cells stimulated with angiotensin II. The phosphorylation of Akt was induced by angiotensin II treatment and inhibited by candesartan, as well as by LY294002, an inhibitor of phosphoinositide 3-kinase. Oxidative stress-related proteins were up-regulated by angiotensin II and inhibited by pretreatment with candesartan or catalase. The level of 8-hydroxy-2'-deoxyguanosine was increased by angiotensin II and conversely decreased by candesartan. Immunocytochemical studies showed that angiotensin II enhanced an inflammatory marker, inducible nitric oxide synthase, and the production of O(2)(-) radical. The hypothesis that angiotensin II has the potential to induce oxidative stress, which may be implicated in carcinogenesis of the prostate gland through long-term exposure to chronic inflammation is proposed.

Involvement of EGFR in the response of squamous cell carcinoma of the head and neck cell lines to gefitinib.

Epidermal growth factor receptor (EGFR) gene mutations are associated with the sensitivity of non-small cell lung carcinomas (NSCLCs) to gefitinib, but such findings have not been reported in squamous cell carcinomas of the head and heck (SCCHNs). Accordingly, we determined whether EGFR gene expression and mutations correlate with the in vitro efficacy of gefitinib in SCCHN cell lines. EGFR status was analyzed in 16 different SCCHN cell lines by polymerase chain reaction (PCR) and direct sequencing for activating mutations, by real-time quantitative RT-PCR, and by Western blot analysis for RNA and protein expression. Using direct sequencing of PCR products from exons 18-23 of 9 SCCHN cell lines, we found a heterozygous EGFR mutation (EGFRmut) with a 2607Gright curved arrow A transition in exon 20 (G/A genotype). The 9 different cell lines that showed this mutation also showed higher sensitivity (lower IC50 values) to gefitinib than cell lines with wild-type EGFR (EGFRwt: G/G genotype) (p=0.016). EGFR protein levels correlated robustly (r=0.76) and significantly (p=0.0007) with EGFR mRNA levels and with IC50 values for gefitinib (r=0.65, p=0.0067). EGFR mRNA correlated with IC50 values (r=0.67, p=0.0046). Our conclusion was that the heterozygous and synonymous transition of the EGFR gene and low EGFR expression levels of mRNA and protein in SCCHN may be reliable predictors of high sensitivity in SCCHN patients to gefitinib.