Annexin A1 (ANXA1) protein expression was evaluated by Western blot in a series of 32 head and neck squamous cell carcinomas (HNSCCs) in a search for molecular alterations that could serve as useful diagnostic/prognostic markers. ANXA1 down-regulation was observed in 24 cases (75%) compared with patient-matched normal epithelium. In relation to clinicopathological variables, ANXA1 down-regulation was significantly associated with advanced T stages (P = 0.029), locoregional lymph node metastases (P = 0.038), advanced disease stage (P = 0.006), hypopharyngeal localization (P = 0.038), and poor histological differentiation (P = 0.005). ANXA1 expression was also analyzed by immunohistochemistry in paraffin-embedded sections from 22 of 32 HNSCCs and 8 premalignant lesions. All dysplastic tissues showed significantly reduced ANXA1 expression compared to a strong positive signal observed in adjacent normal epithelia (except basal and suprabasal cells). A close association was observed between ANXA1 expression and the histological grade in HNSCC. Well-differentiated tumors presented a positive ANXA1 signal in highly keratinized areas whereas moderately and poorly differentiated tumors exhibited very weak or negative staining. Our findings clearly identify ANXA1 as an effective differentiation marker for the histopathological grading of HNSCCs and for the detection of epithelial dysplasia.
Ains-To study the loss of heterozygosity and the presence of mutations at the p53, pl6/CDKN2, and APC genes in Barrett's oesophagus, low grade dysplastic oesophageal epithelium, and adenocarcinoma of the oesophagus; to relate the presence of alterations at these genes with the progression from Barrett's oesophagus to adenocarcinoma.
The immunosuppressive and antiinflammatory actions of glucocorticoid hormones are mediated by their transrepression of activating protein-1 (AP-1) and nuclear factor-kappa B (NFκB) transcription factors. Inhibition of the c-Jun NH2-terminal kinase (JNK) signaling pathway, the main mediator of AP-1 activation, has been described in extracts of hormone-treated cells. Here, we show by confocal laser microscopy, enzymatic assays, and immunoblotting that the synthetic glucocorticoid dexamethasone inhibited tumor necrosis factor α (TNF-α)–induced phosphorylation and activation of JNK in the cytoplasm and nucleus of intact HeLa cells. As a result, c-Jun NH2-terminal domain phosphorylation and induction were impaired. Dexamethasone did not block the TNF-α–induced JNK nuclear translocation, but rather induced, per se, nuclear accumulation of the enzyme. Consistently with previous findings, a glucocorticoid receptor mutant (GRdim), which is deficient in dimerization, DNA binding, and transactivation, but retains AP-1 transrepressing activity, was as efficient as wild-type GR in mediating the same effects of dexamethasone on JNK in transfected Cos-7 cells. Our results show that glucocorticoids antagonize the TNF-α–induced activation of AP-1 by causing the accumulation of inactive JNK without affecting its subcellular distribution.
Glaucoma is a progressive ocular syndrome characterized by degeneration of the optic nerve and irreversible visual field loss. Elevated intraocular pressure (IOP) is the main risk factor for glaucoma. Increased IOP is the result of an imbalance between synthesis and outflow of aqueous humor (AH). Blocking β2 adrenergic receptor (ADRB2) has shown to reduce IOP by decreasing production of AH at the ciliary body (CB). SYL040012 is a siRNA designed to specifically silence ADRB2 currently under development for glaucoma treatment. Here, we show that SYL040012 specifically reduces ADRB2 expression in cell cultures and eye tissues. The compound enters the eye shortly after administration in eye drops and is rapidly distributed among structures of the anterior segment of the eye. In addition, SYL040012 is actively taken up by cells of the CB but not by cells of systemic organs such as the lungs, where inhibition of ADRB2 could cause undesirable side effects. Moreover, SYL040012 reduces IOP in normotensive and hypertensive animal models and the effect appears to be long lasting and extremely well tolerated both locally and systemically.
BackgroundPodoplanin expression is attracting interest as a marker for cancer diagnosis and prognosis. We therefore investigated the expression pattern and clinical significance of podoplanin during the development and progression of laryngeal carcinomas.ResultsPodoplanin expression was determined by immunohistochemistry in paraffin-embedded tissue specimens from 84 patients with laryngeal premalignancies and 53 patients with laryngeal squamous cell carcinomas. We found podoplanin expression extending from the basal to the suprabasal layer of the epithelium in 37 (44%) of 84 dysplastic lesions, whereas normal epithelium showed negligible expression. Patients carrying podoplanin-positive lesions had a higher laryngeal cancer incidence than those with negative expression reaching borderline statistical significance (51% versus 30%, P = 0.071). Podoplanin expression in laryngeal carcinomas exhibited two distinct patterns. 20 (38%) cases showed diffuse expression in most tumour cells and 33 (62%) focal expression at the proliferating periphery of tumour nests. High podoplanin expression was inversely correlated with T classification (P = 0.033), disease stage (P = 0.006), and pathological grade (P = 0.04). There was a trend, although not significant, towards reduced disease-specific survival for patients with low podoplanin levels (P = 0.31) and diffuse expression pattern (P = 0.08).ConclusionsPodoplanin expression increases in the early stages of laryngeal tumourigenesis and it seems to be associated with a higher laryngeal cancer risk. Podoplanin expression in laryngeal squamous cell carcinomas, however, diminishes during tumour progression. Taken together, these data support a role for podoplanin expression in the initiation but not in the progression of laryngeal cancers.
The PI3K/AKT/mTOR signaling pathway has emerged as one of the most frequently deregulated in head and neck squamous cell carcinomas (HNSCC). Numerous alterations of various upstream and downstream components have been described; however, their prognostic significance and impact on HNSCC patient survival remains to be established. This was addressed using an unbiased cohort of 93 consecutive and homogeneous surgically treated HNSCC patients and results confirmed in 432 HNSCC patients. Our findings reveal the high prevalence of S6 phosphorylation, a surrogate marker of mTORC1 activation, in HNSCC specimens (>70%) and, more importantly, demonstrate its relevance on clinical outcome. Phosphorylation of ribosomal protein S6 on either Ser235/236 or Ser240/244 was consistently and significantly correlated with favorable prognosis, although with differences depending on the tumor site. Thus, p-S6 expression was significantly correlated with better disease-specific survival specifically in the subgroup of laryngeal carcinoma patients (P< 0.001). In addition, multivariate regression models revealed p-S6 to be an inverse and independent predictor of lymph-node metastasis (P= 0.004) and distant metastasis (P= 0.006). Taken together, this study unveils an unprecedented correlation of mTOR activation with improved clinical outcome in patients with laryngeal carcinomas and uncovers the potential of p-S6 expression as a good prognostic biomarker and an inverse predictor of lymph node and distant metastases. These results should be of broad interest as immunohistochemical detection of p-S6 may help to stratify patients and guide treatment decisions.
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