Sex hormone receptor levels in laryngeal carcinoma: a comparison between protein and RNA evaluations

Laryngeal Cancer Cells Metabolize 25-Hydroxyvitamin D3 and Respond to 24R,25-dihydroxyvitamin D3 via a Mechanism Dependent on Estrogen Receptor Levels

Studies have evaluated vitamin D3's therapeutic potential in estrogen-responsive cancers, with conflicting findings. We have shown that the proliferation of breast cancer cells is regulated by 24R,25-dihydroxyvitamin D3 (24R,25(OH)2D3) depending on estrogen receptor alpha 66 (ERα66) expression, suggesting that this could also be the case for estrogen-sensitive laryngeal cancer cells. Accordingly, we examined levels of ERα isoforms in ERα66-positive UM-SCC-12 and ERα66-negative UM-SCC-11A cells and their response to 24R,25(OH)2D3. 24R,25(OH)2D3 stimulated proliferation, increased the expression of metastatic markers, and inhibited apoptosis in UM-SCC-12 cells while having the opposite effect in UM-SCC-11A cells. To evaluate if vitamin metabolites could act via autocrine/paracrine mechanisms, we assessed the expression, protein levels, and activity of vitamin D3 hydroxylases CYP24A1 and CYP27B1. Both cell types expressed both mRNAs; but the levels of the enzymes and their activities were differentially regulated by estrogen. ERα66-negative UM-SCC-11A cells produced more 24,25(OH)2D3 than UM-SCC-12 cells, but comparable levels of 1,25(OH)2D3 when treated with 25(OH)D3 These results suggest that the regulation of vitamin D3 metabolism in laryngeal cancer cells is modulated by ERα66 expression, and support a role for 24R,25(OH)2D3 as an autocrine/paracrine regulator of laryngeal cancer. The local metabolism of 25(OH)D3 should be considered when determining the potential of vitamin D3 in laryngeal cancer.

Digit ratio (2D:4D), laryngeal cancer and vocal fold leukoplakia

BACKGROUND

To date, there are no studies that have analyzed the possible influence of exposure to prenatal sex hormones on the risk of laryngeal cancer (LC) and premalignant laryngeal lesion-vocal fold leukoplakia (VFL). Digit ratio (2D:4D) is suggested to be a proxy of prenatal sex hormone exposure.

OBJECTIVE

To examine 2D:4D in patients with LC and clarify if it could add to the verified risk factors in estimating the overall risk of LC.

METHODS

511 subjects participated in the study. The study group included 269 patients: with LC (N = 114, 64 men) and VFL (N = 155, 116 men). Controls included 242 healthy individuals (66.40 ± 4.50 years (106 men)).

RESULTS

Predictive models estimating the risk of VFL and LC in women, based solely on predictors like smoking and alcohol consumption had a lower area under the ROC curve (AUC) than the model with left 2D:4D. AUC for the model estimating the likelihood of VFL increased from 0.83 to 0.85, and for LC from 0.76 to 0.79.

CONCLUSIONS

Low left 2D:4D may be associated with an increased risk of developing leukoplakia and laryngeal cancer in women. In the case of laryngeal cancer, left 2D:4D may serve as additional variable (to other known risk factors, such as smoking and/or alcohol consumption), which can improve cancer risk prediction.

Loss of Estrogen Receptors is Associated with Increased Tumor Aggression in Laryngeal Squamous Cell Carcinoma

Laryngeal squamous cell carcinoma (LSCC) responds to 17β-estradiol via estrogen-receptor (ER, transcribed from ESR1) dependent mechanisms, but is not recognized as a hormonally responsive cancer. 17β-estradiol production by LSCC cell lines UM-SCC-11A and UM-SCC-12 was examined. Wild type (WT) and ESR1-silenced LSCC cultures and xenografts were examined for 17β-estradiol responsiveness in vivo. 14 LSCC and surrounding epithelial samples at various pathological stages were obtained from patients; ERα and ERβ expression were verified using data from the total cancer genome atlas. UM-SCC-11A and UM-SCC-12 both produce 17β-estradiol, but only UM-SCC-12, not UM-SCC-11A, xenograft tumors grow larger in vivo in response to systemic 17β-estradiol treatments. ERα66 and ERα36 expression inversely correlated with clinical cancer stage and tumor burden. LSCC ERα66 expression was higher compared to surrounding epithelia in indolent samples but lower in aggressive LSCC. ERβ expression was highly variable. High ESR1 expression correlated with improved survival in LSCC. Loss of ERα66 expression inversely correlated with prognosis in LSCC. ERα66 may be a histopathological marker of aggression in LSCC.

Estrogen signaling and estrogen receptors as prognostic indicators in laryngeal cancer

Laryngeal squamous cell carcinoma (LSCC) has been shown to respond to 17β-estradiol. However, the presence and characterization of estrogen receptors (ER) and other sex hormone receptors in LSCC are still being determined. Sex hormone receptors and the way sex hormones impact LSCC tumors are important for understanding which patients would benefit from hormone therapies, such as anti-estrogen therapies. This information also has prognostic value, as there may be a correlation between ER profiles and LSCC aggression. Recent work by our team and others has shown that the canonical ER, estrogen receptor α (ERα), and its splice variant ERα36, are important modulators of estrogen signaling in LSCC. This review describes some common 17β-estradiol signaling pathways, and explains how these signaling pathways might control LSCC tumor growth. We also show that loss of ERα, but not ERα36, imbues LSCC with enhanced aggression, a pattern which has previously only been observed in breast cancer. We make a case for using ERα as a tumorigenic modulator and pathogenic marker in LSCC on par with the use of ERα as a prognostic marker in breast cancer.

Novel pipeline identifies new upstream ORFs and non-AUG initiating main ORFs with conserved amino acid sequences in the 5' leader of mRNAs in Arabidopsis thaliana

Eukaryotic mRNAs contain a 5' leader sequence preceding the main open reading frame (mORF) and, depending on the species, 20%-50% of eukaryotic mRNAs harbor an upstream ORF (uORF) in the 5' leader. An unknown fraction of these uORFs encode sequence conserved peptides (conserved peptide uORFs, CPuORFs). Experimentally validated CPuORFs demonstrated to regulate the translation of downstream mORFs often do so in a metabolite concentration-dependent manner. Previous research has shown that most CPuORFs possess a start codon context suboptimal for translation initiation, which turns out to be favorable for translational regulation. The suboptimal initiation context may even include non-AUG start codons, which makes CPuORFs hard to predict. For this reason, we developed a novel pipeline to identify CPuORFs unbiased of start codon using well-annotated sequence data from 31 eudicot plant species and rice. Our new pipeline was able to identify 29 novel Arabidopsis thaliana (Arabidopsis) CPuORFs, conserved across a wide variety of eudicot species of which 15 do not initiate with an AUG start codon. In addition to CPuORFs, the pipeline was able to find 14 conserved coding regions directly upstream and in frame with the mORF, which likely initiate translation on a non-AUG start codon. Altogether, our pipeline identified highly conserved coding regions in the 5' leaders of Arabidopsis transcripts, including in genes with proven functional importance such as LHY, a key regulator of the circadian clock, and the RAPTOR1 subunit of the target of rapamycin (TOR) kinase.

Estradiol receptor profile and estrogen responsiveness in laryngeal cancer and clinical outcomes

There is growing evidence that laryngeal cancers are responsive to sex hormones, specifically 17β-estradiol (E₂), despite controversy regarding the presence and characterization of E₂ receptors (ER). Determination of sex hormone responsiveness impacts the prognosis of laryngeal cancer patients and the treatment modalities implemented by their clinicians. Discovery of membrane-associated steroid hormone receptors and rapid membrane signaling opened the possibility that cancers previously labeled 'non-hormone dependent' and 'ER negative' might in fact be susceptible to the effects of E₂ via these membrane receptors. ERα66 and ERβ, the classical nuclear receptors, are present in the membranes of different cancer cells via a mechanism referred to as trafficking. Novel splice variants of these traditional receptors, a key example being ERα36, have also been found in the caveolae of cancer cells. Previous work demonstrated that ERα36 has a role in the tumorigenesis of laryngeal cancer, enhancing both proliferation and the anti-apoptotic effect of E₂ against chemotherapeutics. The present study showed that expression of different membrane ERs in laryngeal cancer is not uniform, which may result in differential and even antagonistic responses to E₂. E₂ had protective or deleterious effects in different cancer cell lines, stimulating proliferation and conferring anti-apoptotic potential to the cancer cells according to their receptor profile. These findings stress the importance of establishing the molecular and clinical characterization of the specific laryngeal tumor in order to tailor treatment accordingly, thus optimizing care while reducing adverse effects for individual patients.

Expression of hormone receptors in oropharyngeal squamous cell carcinoma

OBJECTIVES

Hormone receptors play an important role in many types of cancers. Alongside factors associated with human papillomavirus (HPV) infection, hormonal receptors may impact the tumorigenesis of oropharyngeal cancer.

MATERIALS AND METHODS

This study consists of 199 consecutive oropharyngeal squamous cell carcinoma (OPSCC) patients diagnosed and treated with a curative intent. We examined androgen (AR), estrogen (ER; both alpha and beta), and progesterone receptor (PR) expressions using immunohistochemistry comparing tumor and patient characteristics.

RESULTS

AR was expressed in 16%, PR in 27% and ER-beta in 63% of the tumors. HPV- and p16-positive tumors expressed more AR and less PR than their negative counterparts. High PR expression was associated with poor disease-specific and locoregional recurrence-free survival.

CONCLUSION

AR, PR, and ER-beta are expressed in OPSCC, and AR and PR expressions are associated with HPV and p16 status. Furthermore, PR appears to have prognostic significance. This may allow us to investigate the role of anti-hormone receptors in the treatment of OPSCC.

Sex-related hormone receptor in laryngeal squamous cell carcinoma: correlation with androgen estrogen-ɑ and prolactin receptor expression and influence of prognosis

BACKGROUND

The expression and function of androgen receptors (AR) and estrogen receptor alpha (ER-ɑ) in laryngeal squamous cell carcinoma (LSCC) have remained controversial for decades. Prolactin receptor (PRLR) is a sex-related hormone, that has been rarely documented in terms of expression or function compared with data on other hormone receptors in laryngeal carcinoma.

METHODS

This study reports on immunohistochemical and reverse transcription-polymerase chain reaction (RT-PCR) analysis of tumour tissue and adjacent normal tissue in 96 patients with LSCC (82 males and 14 females). The expression levels of the receptors were related to clinicopathologic parameters and survival data.

RESULTS

At both protein and mRNA levels, the expression level of AR, ER-ɑ, and PRLR was much higher in LSCC than in adjacent normal tissues (p < .05). Among them, higher PRLR expression in tumour tissues tended to have a significantly poorer survival rate (p = .03) for patients with LSCC. Furthermore, higher expression of ER-ɑ in tumours was correlated with higher expression level of PRLR (r = .823, p = .03).

CONCLUSION

The findings of this study indicate that the sex-related hormone receptors play an important role in the development of LSCC. The PRLR represents a novel prognosticator, because of its negative effect on survival and its interaction with ER-ɑ.

Expression of estrogen and progesterone receptors across human malignancies: new therapeutic opportunities

Estrogen and progesterone receptors (ERs and PRs) are known for their prognostic as well as treatment predictive value in breast cancer. Although these receptors are differentially expressed in some other malignancies, and likely participate in the biology of those cancer types, the relevance to outcome and therapy is not well established. The use of ER as a highly effective therapeutic target in oncology was pioneered in breast cancer, and the lessons learned from its success could potentially benefit patients with several other malignancies in which hormone receptors are highly expressed. Indeed, there are several potent drugs available that target hormone receptors. These agents show incontrovertible evidence of benefit in patients with hormone receptor-positive breast cancer. It is conceivable that these drugs may have salutary effects in a variety of cancers other than those originating in the breast, based on the overexpression of hormone receptors in some patients, and the preclinical and clinical reports showing responses to these drugs in diverse cancers, albeit in small series or anecdotally. We therefore undertook a literature review in order to summarize the current data regarding the biologic and clinical implications of expression of estrogen and progesterone receptors in various malignancies and the possibilities for deployment of hormone manipulation beyond breast cancer.

The prognostic significance of estrogen receptor β in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the fifth most common cancer in the world. Although multimodal and targeted therapy is now used in therapeutic procedures, the survival of patients with HNSCC has remained unchanged over the last 30 years. A number of studies have demonstrated that the increased expression of intranuclear ERβ in breast, lung and colon cancer is a favorable prognostic marker associated with higher survival rates. However, the clinical significance of sex hormone receptors in HNSCC remains unclear. The current study aimed to assess the expression of ERβ in HNSCC immunohistochemically and investigate any possible association between ERβ expression, and clinical and histopathological factors, disease recurrence and patient survival. The present study included 174 patients (165 males and 9 females) with a median age of 60.8 years (range, 39–79) with HNSCC who were primary surgically treated between January 2000 and December 2006. Immunohistochemical reactions for ERβ demonstrated that 73 patients (42%) exhibited positive ERβ expression. Distribution of ERβ status among different head and neck subsites indicated that >40% of all negative cases were located in laryngeal primaries, while incidence of other sublocalization within positive cases was similar and comparable (P=0.04). Furthermore, a correlation was observed between ERβ immunopositivity and the survival of patients, with respect to the primary tumor site. Patients with ERβ positive oropharyngeal cancer had a survival rate of 35.3% at 5-years compared with 25% for patients with negative expression. However, ERβ status was not significantly correlated with any other clinical or histopathological parameter. After an average follow-up time of 38.5 months (range, 3–60 months), 54 patients (31.1%) had succumbed to disease recurrence while 50 (28.7%) succumbed to other causes. In conclusion, ERβ positivity indicates improved survival of patients with oropharyngeal cancer. Further research is required in order to implement novel therapeutic strategies.

Neutrophil-Lymphocyte Ratio as a Prognostic Factor in Laryngeal Carcinoma

Aim of this study; investigate whether neutrophils/lymphocyte ratio (NLR) could be used as a prognostic factor in larynx cancer. The correlation between preoperative peripheral blood NLR and age, gender, smoking, alcohol use, clinical stage and differentiation degree was examined. One hundered fourty-four patients in Dicle University Department of Otorhinolaryngology between the years of 2005 and 2014 were included in the study. Clinical and preoperative laboratory data of patients were screened retrospectively from archive files of otorhinolaryngology and the pathology results were screened retrospectively from archive files of pathology. The study was approved by the local ethics committee of the department and carried out in accordance with the declaration of Helsinki as amended in 2013. Statistical analyses were performed using the SPSS 15.0 software package for Windows (SPSS inc., Chicago, IL, USA). There was a significant difference between NLR and clinical stage (p = 0.003) smoking (p = 0,001) and alcohol use (p = 0.001). When NLR was analyzed in detail according to the degree of tumor differentiation; significant differences were observed between G1 and G2 (p = 0.007) and between G1 and G3 (p = 0.001). Light of these findings, NLR is a cheap and easily accessible marker which can be used as a prognostic faxtor in laryngeal cancer. It is thougkt to shed light on the studies which will be conducted with more patients.

Retrospective analysis of prognostic factors in 205 patients with laryngeal squamous cell carcinoma who underwent surgical treatment

Objectives

To investigate the most important factors affecting the prognosis of the patients with squamous cell carcinoma (SCC) of the larynx.

Methods

Based on the clinical and follow-up data, 205 patients with SCC of the larynx receiving total laryngectomy, partial laryngectomy, or CO₂ laser surgery in GuangDong General Hospital were retrospectively analyzed. A survival analysis was performed by the Kaplan-Meier method and a multivariable analysis of prognostic factors was carried out using the Cox proportional hazard model.

Results

Subtypes of carcinoma included 69.8% glottic and 30.2% supraglottic. Most patients were in N0 stage (77.6%), and 22.4% patients were in N1∼N3 stage. Over half of the patients were in T1∼T2 stage (55.1%), 20.0% in T3, and 24.9% in T4. Mean follow-up duration was 49.2 months. The survival rates 1, 2, and 3 years after the surgery were 99.0%, 91.7%, and 81.5%, respectively. The survival rate for those patients with clinical stage IV was significantly lower than for those with clinical stage I and II (p<0.001 and p = 0.013, respectively). The disease-free progression rates 1, 2, and 3 years after the surgery were 83.9%, 74.6%, and 71.2%, respectively. Futhermore, those patients with a Charlson score of 1 to 2 and ≥3 had higher risk of mortality than those with a Charlson score of 0 (hazard ratios of 1.8 and 2.41 p = 0.042 and p = 0.008). Multivariable analysis revealed that clinical stage, surgical margin, and comorbidity were significantly associated with both mortality and disease-free progression.

Conclusion

The surgical resection margin, clinical stage, and comorbidity were independent factors affecting the laryngeal cancer prognosis. The survival rates were lower for patients with advanced laryngeal cancer, positive surgical margins, or severe comorbidity, suggesting the importance of early diagnosis, early treatment, negative surgical margins, and conditions of comorbidity.

Cytotoxicity of herbal extracts used for treatment of prostatic disease on head and neck carcinoma cell lines and non-malignant primary mucosal cells

Previously, a growth inhibiting effect of PC-Spes on head and neck carcinoma cell lines had been demonstrated. In order to determine the toxic impact of particular herbs in the mixture, we exposed the head and neck cancer cell lines FADU, HLaC79 and its Paclitaxel-resistant subline HLaC79-Clone1 as well as primary mucosal keratinocytes to increasing concentrations of the herbal mixture Prostaprotect, which has a similar formulation as PC-Spes, as well as its single herbal components Dendranthema morifolium, Ganoderma lucidium, Glycyrrhiza glabra, Isatis indigotica, Panax pseudo-ginseng, Rabdosia rubescens, Scutellaria baicalensis and Pygeum africanum. Growth inhibition was measured using the MTT assay. Expression of P-glycoprotein (P-GP), multidrug resistance protein-1 (MRP-1), multidrug resistance protein-2 (MRP-2), breast cancer resistance protein (BCRP) and androgen receptor (AR) were examined by western blot analysis. Pygeum africanum extract clearly turned out as the main cytotoxic component of the Prostaprotect prescription mixture, and initated apoptosis in sensitive cell lines. All other extracts had only minor toxic effects. Western blot analysis revealed increased expression of P-GP in HLaC79-Clone1 cells, while HLaC79 and FADU cells were negative. All three cell lines were negative for MRP-1 and BCRP but positive for MRP-2. HLaC79 and its descendant HLaC79-Clone1 both expressed AR, as verified by western blotting and immunofluorescence staining. Primary mucosal keratinocytes were negative for all multidrug resistance markers as well as for AR. Growth inhibition rates of the single herbal extracts were compared with previously published results in prostate carcinoma cell lines. The relationship between expression levels of AR and multidrug resistance markers in relation to the measured toxicity of herbal extracts in our head and neck cancer cell system is critically discussed.

Estrogen receptor α and β in esophageal squamous cell carcinoma

A gender difference has been reported in the morbidity of esophageal squamous cell carcinoma (ESCC). Estrogens have been proposed to play a role in this difference but the details have not yet been clarified. Therefore, in the present study, we examined the status of estrogen receptor (ER)α and ERβ in 90 Japanese ESCC patients. ERα and ERβ immunoreactivity was detected in the nuclei of ESCC cells (41.1 and 97.8%, respectively). There was a significant positive association between the ERβ H score and histological differentiation (P = 0.0403), TNM-pM (LYM) (P = 0.00164) and Ki67/MIB1 LI of carcinoma cells (P = 0.0497, r = 0.207). In addition, the ERβ status of carcinoma cells was significantly correlated with unfavorable clinical outcome of the patients. Multivariate analysis further revealed the ERβ status in carcinoma cells as an independent unfavorable prognostic factor of these patients. We further examined the effects of estrogen treatment on ESCC cell line (ECGI-10) transfected with ERα or ERβ in vitro. The number of ECGI-10 transfected with ERβ was increased by estradiol or ERβ specific agonist but estradiol did not exert any effect upon the cell number of ECGI-10 transfected with ERα. In summary, the results of the present study clearly demonstrate that the status of ERβ in ESCC was closely associated with the unfavorable prognosis, possibly through altering cell proliferation of carcinoma cells.

Androgen receptor in laryngeal carcinoma: could there be an androgen-refractory tumor?

Androgen receptors (ARs) which are implicated in the pathogenesis of several malignancies can also be a possible downstream effector in laryngeal cancer. In the present study, 97 invasive squamous laryngeal carcinomas were studied by immunohistochemistry for protein expression of AR. Androgen receptors were expressed in 52.6% of tumor specimens, suggesting their implication in the pathogenesis of this tumor. Our study's aim was to investigate the hypothetical scenario of an androgen refractory laryngeal carcinoma where androgen receptors can be activated by nodal molecules in the course of an Epithelial-to-mesenchymal transition (EMT) phenomenon. In line with this we correlated AR expression with the expression of ILK, p-Akt, E-cadherin, β-catenin in our sample as well as with tumor grade and TNM stage. A reverse correlation between nuclear AR and cytoplasmic ILK expression was evidenced, indicating an interaction of those molecules in laryngeal carcinoma. Finally in our material, in those carcinomas that were expressing ARs, stronger nuclear expression of the receptor was characterized by poorer cell differentiation and correlated with the acquisition of EMT features like E-cadherin loss and β-catenin translocation raising a question whether activated ARs can drive an EMT procedure.

A sex-specific association between a 15q25 variant and upper aerodigestive tract cancers

BACKGROUND

Sequence variants located at 15q25 have been associated with lung cancer and propensity to smoke. We recently reported an association between rs16969968 and risk of upper aerodigestive tract (UADT) cancers (oral cavity, oropharynx, hypopharynx, larynx, and esophagus) in women (OR = 1.24, P = 0.003) with little effect in men (OR = 1.04, P = 0.35).

METHODS

In a coordinated genotyping study within the International Head and Neck Cancer Epidemiology (INHANCE) consortium, we have sought to replicate these findings in an additional 4,604 cases and 6,239 controls from 10 independent UADT cancer case-control studies.

RESULTS

rs16969968 was again associated with UADT cancers in women (OR = 1.21, 95% CI = 1.08-1.36, P = 0.001) and a similar lack of observed effect in men [OR = 1.02, 95% CI = 0.95-1.09, P = 0.66; P-heterogeneity (P(het)) = 0.01]. In a pooled analysis of the original and current studies, totaling 8,572 UADT cancer cases and 11,558 controls, the association was observed among females (OR = 1.22, 95% CI = 1.12-1.34, P = 7 × 10(-6)) but not males (OR = 1.02, 95% CI = 0.97-1.08, P = 0.35; P(het) = 6 × 10(-4)). There was little evidence for a sex difference in the association between this variant and cigarettes smoked per day, with male and female rs16969968 variant carriers smoking approximately the same amount more in the 11,991 ever smokers in the pooled analysis of the 14 studies (P(het) = 0.86).

CONCLUSIONS

This study has confirmed a sex difference in the association between the 15q25 variant rs16969968 and UADT cancers.

IMPACT

Further research is warranted to elucidate the mechanisms underlying these observations.

Getting the message across: cytoplasmic ribonucleoprotein complexes

mRNA-ribonucleoprotein (mRNP) complexes mediate post-transcriptional control mechanisms in the cell nucleus and cytoplasm. Transcriptional control is paramount to gene expression but is followed by regulated nuclear pre-mRNA maturation and quality control processes that culminate in the export of a functional transcript to the cytoplasm. Once in the cytosol, mRNPs determine the activity of individual mRNAs through regulation of localization, translation, sequestration and turnover. Here, we review how quantitative assessment of mRNAs in distinct cytoplasmic mRNPs, such as polyribosomes (polysomes), has provided new perspectives on post-transcriptional regulation from the global to gene-specific level. In addition, we explore recent genetic and biochemical studies of cytoplasmic mRNPs that have begun to expose RNA-binding proteins in an integrated network that fine-tunes gene expression.

Relationship between a family history of malignancy and the incidence of laryngeal carcinoma in the Liaoning province of China

OBJECTIVE

The purpose of this study was to determine the contribution of family history of malignancy to the incidence of laryngeal squamous cell carcinoma.

DESIGN

We performed a retrospective review of classified statistics from the detailed information of cases and matched controls.

SETTING

First Hospital of China Medical University in the Liaoning province of China, between October 2005 and November 2007.

PARTICIPANTS

A total of 288 previously untreated patients with laryngeal cancer and 296 control subjects with non-malignant diseases were analysed by use of a hospital-based case-control study.

MAIN OUTCOME MEASURES

Incidence rates and family history of malignancy.

RESULTS

Single-factor logistic regression analysis indicated that the odds ratio value of a family history of malignancy was 2.0 (95% confidence interval: 1.3-3.2). Multiple logistic regression analysis confirmed this result, with an odds ratio value of 2.3 (95% confidence interval: 1.2-4.5). There was significant association between a family history of malignancy and the development of laryngeal squamous cell carcinoma.

CONCLUSIONS

A family history of malignancy plays an important role in and is an independent risk factor for the incidence of laryngeal carcinoma.

Sucrose control of translation mediated by an upstream open reading frame-encoded peptide

Regulation of gene expression through translational control is common in many organisms. The Arabidopsis (Arabidopsis thaliana) transcription factor bZIP11 is translational repressed in response to sucrose (Suc), resulting in Suc-regulated changes in amino acid metabolism. The 5' leader of the bZIP11 mRNA harbors several upstream open reading frames (uORFs), of which the second uORF is well conserved among bZIP11 homologous genes. The uORF2 element encodes a Suc control peptide (SC-peptide) of 28 residues that is sufficient for imposing Suc-induced repression of translation (SIRT) on a heterologous mRNA. Detailed analysis of the SC-peptide suggests that it functions as an attenuator peptide. Results suggest that the SC-peptide inhibits bZIP11 translation in response to high Suc levels by stalling the ribosome on the mRNA. The conserved noncanonical AUG contexts of bZIP11 uORFs allow inefficient translational initiation of the uORF, resulting in translation initiation of the scanning ribosome at the AUG codon of the bZIP11 main ORF. The results presented show that Suc-dependent signaling mediates differential translation of mRNAs containing SC-peptides encoding uORFs.