Parathyroid hormone-related peptide and parathyroid hormone-related peptide receptor type 1 in locally advanced laryngeal cancer as prognostic indicators of relapse and survival.

BACKGROUND: Parathyroid hormone-related peptide (PTHrP) overexpression and poor patient outcome have been reported for many human tumors, but no studies are available in laryngeal cancer. Therefore, we studied the expression of PTHrP and its receptor, parathyroid hormone-related peptide receptor type 1 (PTH1R), in primary locally advanced laryngeal squamous cell carcinomas (LALSCC) also in relation to the clinical outcome of patients. METHODS: We conducted a retrospective exploratory study, using immunohistochemistry, on PTHrP, PTH1R and HER1 expressions in LALSCC of 66 patients treated with bio-radiotherapy with cetuximab. RESULTS: The expressions of PTHrP and PTH1R in LALSCC were associated with the degree of tumor differentiation (p = 0.01 and 0.04, respectively). Poorly differentiated tumors, with worse prognosis, expressed PTHrP at nuclear level and were PTH1R negative. PTHrP and PTH1R were expressed at cytoplasmic level in normal larynx epithelium and more differentiated laryngeal cancer cells, suggesting an autocrine/paracrine role of PTHrP in squamous cell differentiation of well differentiated tumors with good prognosis. Eighty-one percent HER1 positive tumors expressed PTHrP (p < 0.0001), mainly at nuclear level, consistent with the known up-regulation of PTHrP gene by HER1 signaling. In multivariable analyses, patients with PTHrP positive tumors had a higher relative risk of relapse (HR = 5.49; CI 95% = 1.62-22.24; p = 0.006) and survival (HR = 8.21; CI 95% = 1.19-105.00; p = 0.031) while those with PTH1R positive tumors showed a lower relative risk of relapse (HR = 0.18; CI 95% = 0.04-0.62; p = 0.002) and survival (HR = 0.18; CI 95% = 0.04-0.91; p = 0.029). CONCLUSIONS: In LALSCC nuclear PTHrP and absence of PTH1R expressions could be useful in predicting response and/or resistance to cetuximab in combined therapies, contributing to an aggressive behavior of tumor cells downstream to HER1.

Nuclear HER3 expression improves the prognostic stratification of patients with HER1 positive advanced laryngeal squamous cell carcinoma.

BACKGROUND: Compared to the other members of human epidermal growth factor family receptors (HER), the role of HER3 has not been well defined in laryngeal cancer. The predictive and prognostic role of HER3 has been the focus of clinical attention but the research findings are contradictory, especially in laryngeal squamous cell carcinoma (LSCC). The variable localization of HER3 within cancer cells and the role of HER3 in primary and acquired resistance to HER1-targeted therapies remain unclear. METHODS: We performed a retrospective analysis of two cohorts of 66 homogeneous consecutive untreated primary advanced LSCC patients, in which co-expression of HER1, HER2 and HER3 receptors was investigated by semi-quantitative immunohistochemistry. The association of their pattern of expression with survival was evaluated by Kaplan-Meier and Cox's proportional hazard analyses. Multivariable Cox proportional hazards models were developed to predict median 2- and 3-year RFS and 2.5- and 5-year OS. The Akaike information criterion technique and backwards stepwise procedure were used for model selections. The performance of the final Cox models was assessed with respect to calibration and discrimination. RESULTS: Immunohistochemical labeling for HER1 and HER2 was localized both in the cell membrane and in the cytoplasm, while HER3 labeling was observed both in the cell cytoplasm and in the nucleus. HER3 expression was inversely correlated with HER1 positivity. The expression patterns of HERs were associated with tumor differentiation. In both cohorts of patients, HER1 expression was associated with reduced relapse-free (RFS) and overall survival (OS). In HER1 positive tumors, the co-expression with nuclear HER3 was associated with better RFS and OS, compared with HER3 negative tumors or tumors expressing HER3 at cytoplasmic level. HER3 expressing tumors had a higher Geminin/MCM7 ratio than HER3 negative ones, regardless of HER1 co-expression. Multivariable analyses identified age at diagnosis, tumor site, HER1, HER3 and age at diagnosis, tumor stage, HER1, HER3, as covariates significantly associated with RFS and OS, respectively. Bootstrapping verified the good fitness of these models for predicting survivals and the optimism-corrected C-indices were 0.76 and 0.77 for RFS and OS, respectively. CONCLUSIONS: Nuclear HER3 expression was strongly associated with favourable prognosis and allows to improve the prognostic stratification of patients with HER1 positive advanced LSCC carcinoma.

Independent Prognostic and Predictive Role of Interstitial Macrophages in Kidney Biopsies of IgA Nephropathy Patients.

A relevant percentage of IgAN patients experience a progressive decline in kidney function. According to the KDIGO guidelines, proteinuria and eGFR are the only validated prognostic markers. The role of interstitial macrophages in kidney biopsies of IgAN patients and the outcome of patients treated with renin-angiotensin system inhibitors (RASBs) alone or combined with glucocorticoids were evaluated. Clinical and laboratory records (age, gender, hypertension, hematuria, proteinuria, eGFR, serum creatinine, and therapy), MEST-C parameters of the Oxford classification, C4d deposition, peritubular capillaries, and glomerular and interstitial macrophages in 47 IgAN patients undergoing kidney biopsy consecutively between 2003 and 2016 were examined. A high number of interstitial macrophages significantly correlated with peritubular capillary rarefaction and impairment of kidney function. Cox's multivariable regression analysis revealed that a value > 19.5 macrophages/HPF behaved as an independent marker of an unfavorable outcome. Patients exhibiting > 19.5 macrophages/HPF treated at the time of diagnosis with RASBs combined with methylprednisolone had an estimated probability of a favorable outcome higher than patients treated with RASBs alone. Thus, a value > 19.5 macrophages/HPF in IgAN biopsies can predict an unfavorable outcome and endorse a well-timed administration of glucocorticoids. Studies evaluating urine biomarkers associated with peritubular capillary rarefaction in patients with marked macrophage infiltration may help personalized treatment decisions.

Bioradiotherapy with Cetuximab May Reduce the Risk of Neck Node Relapse in Locoregionally Advanced Laryngeal Glottic Carcinoma: May HER1-Profile Be Useful in the Bioselection of Patients?

The aim of the study was to evaluate survival in patients with advanced glottic laryngeal squamous cell carcinoma treated by bioradiotherapy (BioRT) with cetuximab and eventual salvage surgery (group A, n = 66) or upfront surgery (total laryngectomy or near-total laryngectomy) with or without postoperative radiotherapy (PORT) (group B, n = 66). The predictive role of HER1 expression in the bioselection of tumors was evaluated. Relapse-free (RFS), metastasis-free (MFS), overall (OS) survivals, salvageability, and rates of larynx preservation were analyzed. The two groups were balanced by propensity score method on their baseline characteristics. No significant differences in RFS and OS were found, while MFS results were significantly higher in group A (p = 0.04). Group A showed a 22% reduction in the probability of nodal metastasis (p = 0.0023), mostly in tumors with higher HER1 expression. The salvageability with TL at 3 years was 54% after prior BioRT and 18% after prior upfront NTL (p < 0.05). BioRT with cetuximab showed a reduction in the risk of lymph node relapse, particularly in the case of HER1 positive tumors, and it allowed to achieve a higher rate of functional larynx preservation and a higher salvageability compared with upfront surgery. HER1 analysis could be clinically useful in the bioselection of tumors that may benefit from BioRT with cetuximab, particularly in those with neck node metastatic propensity.

Ischemic injury activates PTHrP and PTH1R expression in human ventricular cardiomyocytes.

The PTHrP/PTH1R signalling system induces calciotropic and myorelaxant effects on the vascular system and plays critical roles in the development of the cardiovascular system. In animal models, PTHrP exerts important effects on heart rate and contractility, particularly under ischemic conditions, while, in human hearts, the expression of PTHrP by cardiomyocytes remains to be defined in both normal and ischemic conditions. The present study has been conducted on 101 autoptical cases and confirmed on nine explanted hearts in order to analyze the expression of the PTHrP/PTH1R system by ventricular myocardium in respect to morphological aspects of the myocardial ischemic damage, myofiber hypertrophy and disarray, coronarosclerosis, age and sex. Immunohistochemistry showed positive cytoplasmic immunostaining for both PTHrP and PTH1R in ventricular cardiomyocytes. The expression levels of the PTHrP/PTH1R system resulted significantly increased (P = 0.0008 and P < 0.0001, respectively) in association with the myocardial ischemic damage and the presence of cardiomyocyte hypertrophy (P = 0.02 and P = 0.009 respectively). Conversely, increased expression levels of PTHrP alone were observed in myofiber disarray (P = 0.04), whereas PTH1R was augmented in coronarosclerosis (P = 0.004) and age (P = 0.001). Taken together, these results demonstrate that human ventricular cardiomyocytes express PTHrP and PTH1R and suggest that the activation of the PTHrP/PTH1R system could represent an aspect of the embryonic gene program typically reactivated by the myocardium when subjected to ischemia and/or hypertrophy.

Docosahexaenoic acid induces apoptosis in lung cancer cells by increasing MKP-1 and down-regulating p-ERK1/2 and p-p38 expression.

Different agents able to modulate apoptosis have been shown to modify the expression of the MAP-kinase-phosphatase-1 (MKP-1). The expression of this phosphatase has been considered a potential positive prognostic factor in lung cancer, and smoke was shown to reduce the levels of MKP-1 in ferret lung. Our aim was to assess whether the n-3 polyunsaturated fatty acid docosahexaenoic acid (DHA), known to inhibit the growth of several cancer cells mainly inducing apoptosis, may exert pro-apoptotic effect in lung cancer cells by modifying MKP-1 expression. We observed that DHA increased MKP-1 protein and mRNA expression and induced apoptosis in different lung cancer cell lines (mink Mv1Lu adenocarcinoma cells, human A549 adenocarcinoma and human BEN squamous carcinoma cells). We inhibited the pro-apoptotic effect of DHA by treating the cells with the phosphatase inhibitor Na(3)VO(4) or by silencing the MKP-1 gene with the specific siRNA. This finding demonstrated that the induction of apoptosis by DHA involved a phosphatase activity, specifically that of MKP-1. DHA reduced also the levels of the phosphorylated MAP-kinases, especially ERK1/2 and p38. Such an effect was not observed when the MKP-1 gene was silenced. Altogether, the data provide evidence that the DHA-induced overexpression of MKP-1 and the resulting decrease of MAP-kinase phosphorylation by DHA may underlie the pro-apoptotic effect of this fatty acid in lung cancer cells. Moreover, they support the hypothesis that DHA may exert chemopreventive action in lung cancer.

Celecoxib up-regulates the expression of the zeta chain of T cell receptor complex in tumor-infiltrating lymphocytes in human cervical cancer.

PURPOSE: We evaluated the effects of celecoxib treatment on tumor-infiltrating lymphocyte (TIL) subsets [CD3(+), CD4(+),CD8(+), CD25(+), and T cell receptor (TCR)-zeta-expressing cells] and tryptase-positive mast cells in cervical tumors. Circulating levels of cytokines [interleukin (IL)-1beta, IL-10, tumor necrosis factor-alpha, IL-6, and IL-12] and angiogenesis-modulating factors (vascular endothelial growth factor and endostatin) have also been analyzed. EXPERIMENTAL DESIGN: Cervical tumor biopsies and blood samples were obtained at the time of diagnosis and after 10 days of celecoxib treatment (400 mg b.i.d., at 8:00 a.m. and 8:00 p.m.) in 27 cases. Immunohistochemistry and ELISA assays were used to assess the expression of biological factors in tumor tissue and circulating levels of cytokines and angiogenic molecules. RESULTS: We showed a statistically significant increase in the percentage of TIL expressing the TCR-zeta chain after celecoxib treatment: indeed, in cases exposed to celecoxib, the percentage of TCR-zeta(+) cells ranged from 5.0 to 50.0 (median, 22.5) with respect to baseline expression (range, 3.0-50.0; median, 10.0; P = 0.0016). There was no significant treatment-related difference in the percentage of CD3(+), CD4(+), CD8(+), and CD25(+) TIL as well as in tryptase-positive cells. IL-12 levels were significantly reduced in posttreatment samples with respect to baseline levels (P = 0.002). We also found a reduction in the circulating levels of vascular endothelial growth factor, and a statistically significant increase of serum endostatin levels (P = 0.035). CONCLUSIONS: We reported the first evidence in humans that celecoxib restores zeta expression by TIL in primary cervical tumors, suggesting that a positive modulation of immune function may serve as an additional mechanism supporting the antitumor effect of this class of drugs.

Class III beta-tubulin overexpression is a prominent mechanism of paclitaxel resistance in ovarian cancer patients.

The vast majority of women with advanced ovarian cancer will ultimately relapse and develop a drug-resistant disease with an overall 5-year survival of <50%. Unfortunately, the mechanisms of drug resistance actually operating in patients are still unknown. To address this issue, in 41 patients affected by advanced ovarian cancer the three main mechanisms of paclitaxel resistance were investigated: overexpression of MDR-1 gene, point mutations at prominently expressed alpha-tubulin and beta-tubulin genes and selective alterations in the expression of beta-tubulin isotypes. MDR-1 and the beta-tubulin isotypes expression were evaluated by semiquantitative and real-time PCR. On the same specimens, quantitative immunohistochemistry was also done in the tumor area. No statistically significant changes of MDR-1 expression were noticed between the sensitive and resistant patients either at the mRNA or protein level. The tubulin mutations for the ubiquitous alpha-tubulin and beta-tubulin genes were evaluated by automated DNA sequencing, and in all patients, no mutations were detected in both resistant and sensitive cases. With regard to the expression of tubulin isoforms, a statistically significant up-regulation of class III beta-tubulin was found in the resistant subset. It is worth noting that this statistically significant increase of the expression of class III beta-tubulin was detectable at the mRNA and protein level. By a direct comparison of the three main known mechanisms of paclitaxel resistance, this study indicates that overexpression of class III beta-tubulin is the most prominent mechanism of paclitaxel resistance in ovarian cancer.

Prognostic role of the ratio between cyclooxygenase-2 in tumor and stroma compartments in cervical cancer.

PURPOSE: The aim of this study was to analyze the clinical role of cyclooxygenase (COX)-2 in a large series of 175 cervical cancer patients. EXPERIMENTAL DESIGN: Immunohistochemistry was performed on paraffin-embedded sections by using rabbit antiserum against COX-2. The tumor:stroma (T/S) ratio of COX-2 expression was used to define the overall COX-2 content in the tumor. RESULTS: The T/S COX-2 ratio values ranged from 0.03 to 48.2 (mean +/- SE, 3.7 +/- 0.5). A total of 95 of 175 patients (54.3%) were scored as having a high (>1) T/S COX-2 ratio. In locally advanced cervical cancer patients who underwent neoadjuvant treatment, the percentage of cases showing a high T/S COX-2 ratio was greater in patients who did not respond to treatment (26 of 29 patients, 89.7%) than in patients with a partial (32 of 50 patients, 64.0%) or complete (19 of 44 patients, 43.2%) response (P = 0.0003). When logistic regression was applied, International Federation of Gynecologists and Obstetricians (FIGO) stage (chi(2) = 11.3; P = 0.0008) and T/S COX-2 ratio (chi(2) = 5.3; P = 0.021) retained an independent role in predicting a poor chance of response. Cases with a high T/S COX-2 ratio had a shorter overall survival (OS) [2-year OS, 61%(95% confidence interval 750-83)] than cases with a low T/S COX-2 ratio (2-year OS, 90%; 95% confidence interval, 81-99; P = 0.0001). In multivariate analysis, the status of T/S COX-2 IDV ratio, together with advanced stage, retained an independent negative prognostic role for OS. CONCLUSIONS: The assessment of COX-2 status in both tumor and stroma compartment could provide valuable information to identify cervical cancer patients endowed with a very poor chance of response to neoadjuvant treatment and unfavorable prognosis.

Cyclooxygenase-2 expression in lymph node metastasis of cervical and vulvar cancer.

Overexpression of cyclooxygenase-2 (COX-2), characterizes tumors with high potential for local invasion and lymph node involvement. We investigated the expression of COX-2 in primary tumors and metastatic regional lymph nodes (TDL) from untreated and chemotherapy treated cervical cancer, as well as vulvar cancer. Immunostaining of COX-2, expressed as values of COX-2 intensity density (COX-2 IDV) was performed on 57 metastatic TDL and 24 corresponding primary rumors from 14 cervical and 9 vulvar cancer patients admitted to the Department of Obstetrics and Gynecology, Catholic University of Rome. In 6 locally advanced cervical cancer tissue samples, from both primary tumor and TDL, were obtained after chemotherapy treatment. In untreated cervical cancer, COX-2 IDV in tumor cells from positive TDL were significantly lower (median 0.69, range 0.22-0.92) than those from primary tumors (median = 3.84, range 0.19-7.67) (p=0.011). In cervical cancer exposed to chemotherapy, COX-2 IDV in tumor cells from positive TDL were significantly lower (median = 2.06, range 1.48-6.52) than those from primary tumors (median = 6.4, range 4.5-13.7) (p=0.037). In vulvar cancer COX-2 IDV in tumor cells from positive TDL were lower (median = 0.39, range 0.02-6.09) than those from primary tumors (median = 2.49, range 0.71-8.10) (p=0.04). In conclusion, we showed that COX-2 expression is down-regulated in cervical and vulvar tumor cells invading the regional lymph nodes with respect to primary tumors, thus emphasizing the need for deeper insight into the tissue specific relation between tumor cells and node microenvironment.

Hu/elav RNA-binding protein HuR regulates parathyroid hormone related peptide expression in human lung adenocarcinoma cells.

In 54 stage I and II human lung adenocarcinomas, HuR and PTHrP levels were positively correlated and the PTHrP-HuR status of the tumor was an independent prognostic marker of the clinical outcomes of patients. The possibility that HuR could upregulate PTHrP expression in lung adenocarcinoma was investigated by immunohistochemical, Western blot and RT-PCR analyses in HCC44 and DV90 human lung adenocarcinoma cell lines. In both cell lines, knockdown of HuR by specific siRNAs reduced PTHrP mRNAs and both cellular and secreted protein. Moreover, it inhibited cell growth and induced cell apoptosis, as revealed by the increase of caspase-3 activity. These effects were partially rescued by the addition of exogenous PTHrP (1-34). Analysis by actinomycin D assay revealed that in both cell lines HuR silencing produced a decrease of PTHrP mRNA half-life by about 70%. These findings add PTHrP to the list of lung cancer-associated genes, whose mRNA is stabilized by HuR.

Expression of the RNA-binding protein HuR and its clinical significance in human stage I and II lung adenocarcinoma.

The ubiquitously expressed RNA-binding protein Hu antigen (HuR) participates in the post-transcriptional regulation of mRNAs bearing U- and AU-rich sequences. Expression of HuR is increased in cancers of the breast, colon, ovary and lung and cytoplasmic immunoreactivity for HuR was found to be closely related to poor outcomes in patients with these tumors. Since the regulation of HuR function is closely linked to its subcellular localization, we evaluated, by quantitative immunohistochemistry, the impact on clinical outcome of both nuclear and cytoplasmic levels (integrated density: ID) of HuR and of nuclear/cytoplasmic ratio (N/C) in 54 lung adenocarcinomas from stage I and II patients. Nuclear and cytoplasmic Hur IDs and N/C were not associated with age, smoking or tumor diameter. Low N/C was significantly associated with lymph-node involvement at presentation. Cox's regression analysis showed that high cytoplasmic, but not nuclear, HuR ID and low N/C were directly associated with the risk of death and metastasis. In the multivariate analysis, low HuR N/C retained an independent negative prognostic significance relative to the risk of metastasis and death. Moreover, the levels of N/C allowed us to discriminate subjects with the highest risk of metastasis and death among patients with lung adenocarcinomas expressing high levels of cytoplasmic HuR. In conclusion, the measure of the ratio between nuclear and cytoplasmic HuR levels allows a sensitive prognostic evaluation of the clinical outcome in early stage lung adenocarcinoma patients.

Parathyroid hormone-related peptide and parathyroid hormone-related peptide receptor type 1 expression in human lung adenocarcinoma.

BACKGROUND: In many primary tumors, parathyroid hormone-related peptide (PTHrP) and PTHrP type 1 receptor (PTH1R) are coexpressed, supporting the possibility that PTHrP/PTH1R system can mediate important signals for tumor progression through paracrine/autocrine mechanisms. In non-small cell lung carcinoma the clinical relevance of the expression of PTH1R remains to be investigated. METHODS: Fifty-four lung adenocarcinomas of mixed histologic type from patients with stage I and II cancer were assayed by quantitative immunohistochemistry for the expression of PTHrP and PTH1R. RESULTS: PTHrP and PTH1R were expressed in a wide range of intensity in the cytoplasm of tumor cells, and their values showed a positive correlation. PTH1R, but not PTHrP, was expressed by plasma cells infiltrating the tumor stroma. PTHrP and PTH1R were not associated with age, tumor diameter, or histopathologic grading, whereas they were directly associated with lymph node involvement at presentation. Cox regression analysis, using PTHrP and PTH1R as continuous covariates, showed that the covariate levels were directly associated with the risk of death and metastasis. Patients whose tumors coexpressed high levels of PTHrP and PTH1R showed the highest risk of metastasis (relative risk, 5.89; 95% CI, 2.1-16.6; P = .0003) and death (relative risk, 6.24; 95% CI, 1.6-23.9; P = .0033). The presence of PTH1R-positive plasma cells in the tumor stroma was associated with a more favorable survival rate independently from the PTHrP status of the tumor. CONCLUSION: The paracrine/autocrine signaling through PTHrP/PTH1R could be important in early-stage lung adenocarcinoma progression.

Expression of cyclooxygenase-2 (COX-2), receptors for estrogen (ER), and progesterone (PR), p53, ki67, and neu protein in endometrial cancer.

OBJECTIVE: We aimed at investigating by immunohistochemistry the relationship between cyclooxygenase-2 (COX-2) and estrogen (ER), and progesterone (PR) receptors in a single institution series of 90 primary untreated endometrial cancer patients. The simultaneous assessment of p53 protein, ki67, and neu protein has been carried out. METHODS: Immunohistochemistry was performed on paraffin-embedded sections by using rabbit polyclonal antiserum against human COX-2, anti-ER (clone 1D5), and anti-PR (clone 1A6) monoclonal antibodies, anti ki67 (clone MIB-1) and p53 (clone DO-7), and polyclonal antibody anti human c-erbB2/neu. RESULTS: There was no difference in the distribution of COX-2, p53, and neu positive cases according to ER or PR positivity, while the percentage of ki67 positive endometrial tumors was significantly higher in ER negative versus ER positive tumors (54.5% versus 31.6%, P value = 0.044). ER and PR positive tumors showed a statistically significant association with clinicopathological parameters of better clinical outcome. There was no clear association between COX-2 positivity and any of the clinicopathological features. The percentage of ki67, p53, and neu positive tumors was found to be strictly related to more aggressive features. Only advanced stage of disease was found to be a predictor of poor prognosis (P value = 0.034). None of the biological parameters examined was shown to be associated with patient outcome. CONCLUSIONS: We showed that COX-2 expression is not correlated with ER, PR, p53, and neu, thus suggesting that COX-2-mediated activities may follow independent pathways. Our findings provide the rationale to design trials based on the combination of antihormones with inhibitors of COX-2 and neu in recurrent/metastatic endometrial cancer.

Expression of cyclooxygenase-2 (COX-2) in non-neoplastic and neoplastic vulvar epithelial lesions.

OBJECTIVE: Cyclooxygenase-2 (COX-2) overexpression has been associated with parameters of tumor aggressiveness and unfavourable clinical outcome in several solid tumors. We investigated by immunohistochemistry the expression of COX-2 in normal vulvar tissue, non-neoplastic vulvar epithelial lesions, vulvar intraepithelial neoplasia (VIN) and invasive vulvar cancer (IVC). METHODS: The expression pattern of COX-2 was studied in normal vulvar tissue, in six cases of lichen sclerosus (LS), seven cases of squamous cell hyperplasia (SCH), 20 VIN, 2 Paget's disease and 36 IVC. The relationship between COX-2 expression and clinicopathologic parameters in IVC patients has been also addressed. Sections were incubated with normal rabbit serum for 15 min, then with rabbit polyclonal antiserum against human COX-2 (Cayman, Ann Arbor, MI, USA). The results were reported as mean +/- standard error (SE) of COX-2 integrated density values (IDV). RESULTS: Higher levels of tumor/stroma COX-2 IDV ratio were found in stages III-IV (mean +/- SE = 3.5 +/- 0.8) than stages I-II disease (mean +/- SE = 1.4 +/- 0.3) (P value = 0.04). In the subgroup of stage I cases, tumor/stroma COX-2 IDV values were higher in cases with > 1 mm stromal invasion (T1b) than cases with <== 1 mm stromal invasion (T1a) (mean +/- SE = 1.6 +/- 0.3 vs. mean +/- SE = 0.6 +/- 0.1) (P = 0.033). Moreover, we observed higher tumor/stroma COX-2 IDV in cases with metastatic lymph node involvement than cases without lymph node involvement (mean +/- SE = 3.5 +/- 0.8 vs. mean +/- SE = 1.3+/-0.4) (P = 0.037). CONCLUSION: This study suggests that COX-2 overexpression may contribute to vulvar tumorigenesis and progression. Moreover, the correlation of tumor/stroma COX-2 IDV ratio with tumor extension and metastatic lymph node involvement, which represent the major prognostic parameters in this neoplasia, implies that tumor/stroma COX-2 IDV ratio could have a prognostic role in vulvar cancer.

Bcl-2 down-regulation is a novel mechanism of paclitaxel resistance.

Taxanes act by inhibiting microtubule dynamics; in this study, we have investigated mitochondria as an additional target of taxanes. We incubated isolated mitochondria in the presence of taxanes with or without stimulation of the mitochondrial respiratory state. Results showed that they rapidly induced the loss of deltapsim after stimulation of the respiratory state. To evaluate the binding of [14C]paclitaxel to isolated mitochondria, mitochondrial proteins were precipitated yielding 18.6 +/- 2.1 cpm/microg of protein. After stimulation of the respiratory state, binding of [14C]paclitaxel increased up to 163.2 +/- 46.7 cpm/microg of protein. CPM values after Bcl-2 immunoprecipitation was 62.8-fold higher than those of the control antibody, thereby indicating the involvement of Bcl-2 in paclitaxel binding. Then, we established a panel of A2780 cell lines resistant to increasing doses of paclitaxel alone or to high doses of paclitaxel/cyclosporin A (A2780 TC cells). In both cases, Bcl-2 expression was consistently down-regulated, whereas levels of other members of the Bcl-2 family, such as Bax and Bcl-x, did not change in paclitaxel-resistant cell lines. When A2780TC cells were stably transfected with a Bcl-2 construct, paclitaxel sensitivity was partially restored, thereby supporting a direct role of Bcl-2 down-regulation in the maintenance of drug-resistance. Finally, we examined Bcl-2 by immunohistochemistry in a small subset of ovarian cancer paclitaxel-resistant patients and we noticed that the protein is down-regulated in this clinical setting with respect to the expression levels found in drug-sensitive tumors. These findings demonstrate that Bcl-2 is an additional intracellular target of taxanes and that its down-regulation is involved in taxane resistance.