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1.
Ann Palliat Med ; 13(2): 249-259, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38584473

RESUMO

BACKGROUND: Predictors of non-completion of radiotherapy (RT) should be identified to determine the optimal RT dose. Therefore, this study aimed to explore factors associated with non-completion of palliative RT in patients with terminal cancer. METHODS: In this retrospective study, patients with terminal cancer who received RT (not including single-fraction RT) for relief of pain caused by spinal metastasis were categorized into complete and incomplete groups. Baseline characteristics, hematologic test data [e.g., total lymphocyte count (TLC)], performance status, palliative performance scale (PPS) score, psoas muscle index (PMI), Charlson comorbidity index, and age-adjusted Charlson comorbidity index of the patients were compared between the two groups. RESULTS: The complete group comprised 58 patients (median age: 68 years; female/male: 17/41; number of irradiation fractions: ≥2 to <10, 20 patients; 10, 34 patients; and >10, 4 patients), and the incomplete group comprised 9 patients (median age: 68 years; female/male: 3/6; number of irradiation fractions: ≥2 to <10, 2 patients; 10, 7 patients; and >10, 0 patient). The proportion of patient death within 1 week or 1 month was higher in the incomplete group than in the complete group. Compared with that in the incomplete group, TLC measured 1 week before RT (pre-TLC) and PMI recorded before RT were significantly higher in the complete group (P=0.013 and P=0.012, respectively). In multivariable analyses, pre-TLC was significantly associated with the incomplete group (P=0.048). Compared with the complete group, the incomplete group included several patients whose PPS scores rapidly decreased. CONCLUSIONS: Pre-TLC can predict non-completion of palliative RT in patients with terminal cancer.


Assuntos
Neoplasias da Coluna Vertebral , Humanos , Masculino , Feminino , Idoso , Estudos Retrospectivos , Neoplasias da Coluna Vertebral/radioterapia , Cuidados Paliativos , Dor
2.
Auris Nasus Larynx ; 51(2): 323-327, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37775468

RESUMO

In Japan, near-infrared photoimmunotherapy (NIR-PIT) was introduced in 2021 as a treatment option for unresectable recurrent head and neck cancer. The treatment targets the epidermal growth factor receptor (EGFR), which is overexpressed in 80-90 % of head and neck squamous cell carcinoma (HNSCC). NIR-PIT should theoretically show therapeutic efficacy if EGFR is expressed, even in nonsquamous cell carcinomas (non-SCC). To the best of our knowledge, there are no case reports of NIR-PIT for non-SCC. We performed NIR-PIT in a patient with non-SCC of the head and neck region. After performing two NIR-PIT treatments, small free clusters of residual tumor cells were observed. Immunostaining in this specimen revealed EGFR expression in residual tumor cells. The residual tumor cells had been irradiated sufficiently to achieve necrosis. It is suggested that not only laser irradiation and expression of EGFR but also other factors are involved in the efficacy of this treatment. Further investigation for these other factors is warranted.


Assuntos
Carcinoma , Neoplasias das Glândulas Salivares , Humanos , Fármacos Fotossensibilizantes/uso terapêutico , Neoplasia Residual/tratamento farmacológico , Ductos Salivares , Linhagem Celular Tumoral , Recidiva Local de Neoplasia/tratamento farmacológico , Fototerapia , Receptores ErbB
3.
Head Neck Pathol ; 17(3): 658-672, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37486532

RESUMO

BACKGROUND: Human papillomavirus (HPV)-associated oropharyngeal cancer occasionally has a poor prognosis, making prognostic risk stratification crucial. Protease-activated receptor-1 (PAR1) is involved in carcinogenesis, and its expression is regulated by alpha-arrestin domain-containing protein 3 (ARRDC3). It is also involved in the tumor microenvironment. We sought to evaluate the predictive ability of PAR1, ARRDC3, and tumor-infiltrating lymphocyte (TIL) scores in patients with oropharyngeal, hypopharyngeal, and uterine cervical cancers, serving as comparators for HPV-associated oropharyngeal cancer. METHODS: Immunohistochemical analysis of p16, ARRDC3, and PAR1 expression was performed on 79 oropharyngeal, 44 hypopharyngeal, and 42 uterine cervical cancer samples. The TIL scores were assessed and classified into the following groups based on invasion: low: 0-10%, medium: 20-40%, and high: > 50%. For prognostic analysis, the three groups were evaluated by dividing them into low, medium, and high categories, or alternatively into two groups using the median value as the cutoff. RESULTS: p16 was expressed in 44 (56%) oropharyngeal, 8 (18%) hypopharyngeal, and all uterine cervical cancer samples. ARRDC3 was detected in 39 (49%) oropharyngeal, 25 (57%) hypopharyngeal, and 23 (55%) uterine cervical cancer samples. PAR1 was expressed in 45 (57%) oropharyngeal, 22 (50%) hypopharyngeal, and 22 (50%) uterine cervical cancer samples. Patients diagnosed with p16-positive oropharyngeal cancer had a substantially improved prognosis compared to those diagnosed with p16-negative cancer. The PAR1-negative cases had a considerably improved prognosis compared to the positive cases (disease-specific survival [DSS] and -negative cases (disease-free survival [DFS]). Multivariate analysis revealed that ARRDC3-positive cases had an appreciably better DSS prognosis than patients with p16-negative oropharyngeal cancers. PAR1-positive patients among patients with p16-positive oropharyngeal cancer had a poor prognosis. With respect to DFS, patients with PAR1-positive and p16-negative oropharyngeal cancer had a 35-fold higher recurrence rate than those with PAR1-negative and p16-negative oropharyngeal cancer. CONCLUSION: Our results suggest that PAR1 expression affects the prognosis and recurrence rate of HPV-associated oropharyngeal cancer.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Orofaríngeas , Infecções por Papillomavirus , Receptor PAR-1 , Neoplasias do Colo do Útero , Feminino , Humanos , Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/patologia , Inibidor p16 de Quinase Dependente de Ciclina/análise , Papillomavirus Humano , Neoplasias Orofaríngeas/patologia , Infecções por Papillomavirus/diagnóstico , Prognóstico , Receptor PAR-1/genética , Microambiente Tumoral
4.
Sci Rep ; 13(1): 6188, 2023 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-37061623

RESUMO

This sentinel node (SN) biopsy trial aimed to assess its effectiveness in identifying predictive factors of micrometastases and to determine whether elective neck dissection is necessary in oral squamous cell carcinoma. This retrospective study included 55 patients from three previous trials, with positive SNs. The relationship between the sizes of the metastatic focus and metastasis in non-sentinel node (NSN) was investigated. Four of the 55 largest metastatic focus were isolated tumor cells, and the remaining 51 were ranged from 0.2 to 15 mm, with a median of 2.6 mm. The difference of prevalence between 46 negative- and 9 positive-NSN was statistically significant with regard to age, long diameter of primary site and number of cases with regional recurrence. In comparing the size of largest metastatic focus dividing the number of positive SN, with metastaic focus range of < 3.0 mm in one-positive SN group, there were 18 (33%) negative-NSN and no positive-NSN. Regarding prognosis, 3-year overall survival rate of this group (n = 18) and other (n = 37) were 94% and 73% (p = 0.04), and 3-year recurrence free survival rate of this group and other were 94% and 51% (p = 0.03), respectively. Absolutely a further prospective clinical trial would be needed, micrometastases may be defined as solitary SN metastasis with < 3.0 mm of metastatic focus, and approximately 33% of neck dissections could be avoided using these criteria.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Humanos , Carcinoma de Células Escamosas/cirurgia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Neoplasias Bucais/cirurgia , Neoplasias Bucais/patologia , Micrometástase de Neoplasia/patologia , Estudos Retrospectivos , Estadiamento de Neoplasias , Biópsia de Linfonodo Sentinela , Neoplasias de Cabeça e Pescoço/patologia , Excisão de Linfonodo , Linfonodos/patologia
5.
Oncotarget ; 9(97): 37008-37016, 2018 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-30651931

RESUMO

BACKGROUND: There is increasing evidence that the inflammatory indices of modified Glasgow prognostic score (mGPS) and high-sensitivity mGPS (HS-mGPS) play important roles in predicting the survival in many cancer; however, evidence supporting such an association in head and neck cancer (HNC) is scarce. MATERIALS AND METHODS: We evaluated the impact of the mGPS and HS-mGPS on the overall survival (OS) in 129 patients with HNC treated at Aichi Cancer Center Central Hospital from 2012-2013. The mGPS was calculated as follows: mGPS of 0, C-reactive protein (CRP) ≤1.0 mg/dl; 1, CRP >1.0 mg/dl; 2, CRP>1.0 mg/dl and albumin <3.5 mg/dl. Regarding the HS-mGPS, the CRP threshold level was set as 0.3 mg/dl. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated by Cox proportional hazard models after adjusting for potential confounders. RESULTS: The prognosis of HNC worsened significantly as both the mGPS and HS-mGPS increased in a univariate analysis. After adjusting for covariates, the HS-mGPS was significantly associated with the OS (adjusted HR for HS-mGPS of 2 compared to an HS-mGPS of 0 [HRscore2-0] 3.14 [95% CI: 1.23-8.07], Ptrend < 0.001), while the mGPS was suggested to be associated with the survival (HRscore2-0 2.37 [95% CI:0.89-6.33], Ptrend = 0.145). Even after stratification by clinical covariates, these associations persisted. CONCLUSION: We conclude that the HS-mGPS is useful as an independent prognostic factor in HNC.

6.
Jpn J Clin Oncol ; 47(12): 1141-1150, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29036621

RESUMO

PURPOSE: We previously reported unfavorable locoregional control with limited field postoperative radiotherapy for head and neck squamous cell carcinoma patients and thus revised the strategy to cover the whole neck. Head and neck squamous cell carcinoma Patients' outcomes were retrospectively analyzed to compare the efficacy of two treatments. MATERIAL AND METHODS: Before 2010, the clinical target volume covered the tumor bed and/or involved the neck region. Since 2011, whole-neck irradiation was planned. Univariate analysis, multivariate analysis, and propensity score matching were performed. The study included 275 patients: 186 received limited field postoperative radiotherapy and 89 received whole-neck postoperative radiotherapy. The median follow-up time for the entire cohort was 40.8 months. RESULTS: In univariate analysis, the radiation strategy had no significant effect on overall survival and progression-free survival. In multivariate analysis, whole-neck postoperative radiotherapy was a favorable factor for overall survival, progression-free survival, and locoregional control. Propensity score matching resulted in a cohort comprising 118 well-matched patients evenly divided between the limited field postoperative radiotherapy and whole-neck postoperative radiotherapy groups. Whole-neck postoperative radiotherapy group achieved a significantly better 2-year overall survival (56.4% vs. 78.1%; P = 0.003), 2-year progression-free survival (34.7% vs. 59.8%; P = 0.009), and 2-year locoregional control (54.4% vs. 83.2%; P < 0.001). The limited field postoperative radiotherapy group developed significantly more locoregional recurrences both in-field (35.2% vs. 15.1%, P = 0.003) and out-of-field (25.0% vs. 0%, P < 0.001) in the matched-pair cohort. CONCLUSION: Whole-neck postoperative radiotherapy is a more appropriate choice than limited field postoperative radiotherapy to improve overall survival, progression-free survival and locoregional control.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/cirurgia , Neoplasias de Cabeça e Pescoço/radioterapia , Neoplasias de Cabeça e Pescoço/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Estudos de Coortes , Terapia Combinada , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Recidiva Local de Neoplasia/patologia , Período Pós-Operatório , Pontuação de Propensão , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
7.
Int J Clin Oncol ; 22(6): 1034-1041, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28623448

RESUMO

BACKGROUD: Laryngeal preservation is an important consideration when treating cervical esophageal cancers (CECs) such as laryngeal cancer. The standard treatment for CEC allowing laryngeal preservation is chemoradiotherapy. However, in cases of laryngeal cancer, chemoselection has also been applied as a treatment strategy that promotes larynx preservation. This strategy involves assigning the appropriate radical treatment according to the primary tumor's response to induction chemotherapy. Since there have been no studies of the application of chemoselection in CEC cases, the present study compared the results, including laryngeal preservation rates, obtained upon applying chemoselection and chemoradiotherapy to CEC. STUDY DESIGN: This was a retrospective cohort study of cervical esophageal squamous cell carcinoma patients treated using chemoselection or chemoradiotherapy at Aichi Cancer Center Hospital between January 2000 and March 2013. A total of 42 patients were enrolled. RESULTS: The 2-year overall survival and laryngeal preservation rates for the chemoselection group versus the primary radiotherapy group were 65.1 and 57.3 versus 40 and 83.3%, respectively (P = 0.017 and P = 0.122, respectively). The 2-year locoregional control rates for the chemoselection and primary radiotherapy groups were 68 and 25%, respectively (P = 0.045). CONCLUSION: The chemoselection group achieved favorable results. Therefore, chemoselection can be applied as a treatment strategy for CEC.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/radioterapia , Quimioterapia de Indução/métodos , Tratamentos com Preservação do Órgão/métodos , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/cirurgia , Quimiorradioterapia , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/cirurgia , Carcinoma de Células Escamosas do Esôfago , Feminino , Humanos , Laringectomia/métodos , Laringe/cirurgia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Faringectomia/métodos , Estudos Retrospectivos , Taxa de Sobrevida
8.
Auris Nasus Larynx ; 44(5): 596-601, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28043710

RESUMO

OBJECTIVE: We aimed to investigate the complications, surgical site infection (SSI), and survival in salvage surgery without free-flap reconstruction for patients with head and neck squamous cell carcinoma who were treated by platinum-based chemoradiotherapy (Plat-CRT) or cetuximab-based bioradiotherapy (Cet-BRT). METHODS: Thirty-three patients treated by Plat-CRT and six treated by Cet-BRT had salvage surgery. We categorized postoperative complications according to the Clavien-Dindo classification and SSI according to the wound grading scale. Overall survival calculated by Kaplan-Meier method. RESULTS: Patients with Cet-BRT were significantly associated with the presence of SSI (P<0.01) and grades IIIb-V of the Clavien-Dindo classification (P<0.01) compared with those with Plat-CRT. Patients with Cet-BRT had a significantly lower overall survival than those with Plat-CRT (P<0.05). CONCLUSION: We demonstrated that patients with Cet-BRT were significantly more associated with the presence of SSI and grades IIIb-V in the Clavien-Dindo classification than those with CRT.


Assuntos
Neoplasias de Cabeça e Pescoço/terapia , Terapia de Salvação/efeitos adversos , Infecção da Ferida Cirúrgica/etiologia , Idoso , Antineoplásicos Imunológicos/administração & dosagem , Cetuximab/administração & dosagem , Quimiorradioterapia , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Humanos , Laringectomia , Masculino , Pessoa de Meia-Idade , Esvaziamento Cervical , Infecção da Ferida Cirúrgica/classificação
9.
Eur Arch Otorhinolaryngol ; 273(12): 4595-4600, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27372745

RESUMO

The lymph node density (LND) has been reported to be a significant prognostic factor in various types of carcinoma. This study investigated whether the LND is associated with survival in patients with hypopharyngeal squamous cell carcinoma (HPSCC) who have positive lymph nodes without distant metastasis. Forty-six patients who were pathologically diagnosed with HPSCC with positive lymph nodes and without distant metastasis were enrolled in this study. The LND was defined as the ratio of positive lymph nodes to the total number of lymph nodes. An LND of ≥0.09 was found to be significantly correlated with a shorter overall (p = 0.044) and disease-specific (p = 0.019) survival according to a log-rank test. In a multivariate survival analysis using a Cox proportional hazards model adjusted for the pathological T category (pT3-4/pT1-2), pathological N category (pN2/pN1) and positive surgical margin and/or extracapsular spread (presence/absence), both an LND of ≥0.09 and pT3-4 category were associated with significantly shorter overall survival (p < 0.01) and disease-specific survival (p < 0.01). These results suggest that the LND functions as a prognostic factor for HPSCC patients with positive lymph nodes who do not have distant metastasis.


Assuntos
Carcinoma de Células Escamosas/mortalidade , Neoplasias Hipofaríngeas/mortalidade , Metástase Linfática , Adulto , Idoso , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Feminino , Humanos , Neoplasias Hipofaríngeas/patologia , Neoplasias Hipofaríngeas/cirurgia , Japão/epidemiologia , Masculino , Margens de Excisão , Análise Multivariada , Esvaziamento Cervical , Estadiamento de Neoplasias , Prognóstico
10.
Jpn J Clin Oncol ; 46(7): 646-51, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27162318

RESUMO

OBJECTIVE: High Charlson comorbidity index values have been reported to be associated with shorter overall survival in various types of cancer. We investigated whether Charlson comorbidity index values were correlated with overall survival in patients with resectable sinonasal tract squamous cell carcinoma. METHODS: Seventy-nine patients with resectable sinonasal tract squamous cell carcinoma were treated with curative intent. The Charlson comorbidity index values were calculated by the summation of the weight scores of 19 medical conditions (other than sinonasal tract squamous cell carcinoma) before treatment. The survival rate was analyzed according to the Kaplan-Meier method. Univariate and multivariate survival analyses were performed using the Wilcoxon test and the Cox proportional hazards model, respectively. RESULTS: According to a univariate analysis, a Charlson comorbidity index value ≥6 was found to be significantly correlated with shorter overall survival (P < 0.02). In the multivariate survival analysis with adjustment for the clinical T and N classification, age, sex, anatomical location, treatment group (radiotherapy/surgery) and chemotherapy (presence/absence), a Charlson comorbidity index value ≥6 was found to be associated with the significantly shorter overall survival. CONCLUSIONS: These results suggest that the Charlson comorbidity index functions as a prognostic factor in cases of resectable sinonasal tract squamous cell carcinoma.


Assuntos
Carcinoma de Células Escamosas/epidemiologia , Comorbidade , Neoplasias de Cabeça e Pescoço/epidemiologia , Neoplasias dos Seios Paranasais/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Taxa de Sobrevida
11.
Acta Otolaryngol ; 134(8): 865-71, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25022795

RESUMO

CONCLUSIONS: The poor response of neck tumors to induction chemotherapy (ICT) as chemoselection is related to a significantly worse prognosis, including higher risks of local recurrence and/or distant metastasis, after definitive chemoradiotherapy (CRT). OBJECTIVES: Neck dissection is frequently performed to treat residual lymph nodes after CRT for the purpose of locoregional control; however, the prognosis of patients with pathologically proven residual neck tumors is poor, and no methods for predicting unfavorable results before CRT have been established. Therefore, in the present study, we focused on the response of lymph nodes to ICT and its relationship with the prognosis among patients treated with chemoselection. METHODS: We retrospectively reviewed a total of 27 oropharyngeal and 24 hypopharyngeal squamous cell carcinoma stage III/IV consecutive patients with cervical lymph node metastasis who exhibited a response of >50% in the primary tumor to ICT followed by concurrent definitive CRT. RESULTS: The relapse-free survival of the patients who responded (partial response/complete response, PR/CR) to ICT was significantly superior to that of the patients who did not respond (stable disease, SD) to ICT (p = 0.008).


Assuntos
Linfonodos/patologia , Recidiva Local de Neoplasia/epidemiologia , Estadiamento de Neoplasias , Neoplasias Faríngeas/terapia , Medição de Risco , Adulto , Idoso , Quimiorradioterapia , Terapia Combinada , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Incidência , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Esvaziamento Cervical , Neoplasias Faríngeas/diagnóstico , Neoplasias Faríngeas/secundário , Prognóstico , Estudos Retrospectivos , Fatores de Risco
12.
Heart Vessels ; 27(1): 53-7, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21331619

RESUMO

Although the maze procedure is often performed as a surgical treatment for atrial fibrillation (AF) combined with mitral valve surgery, the long-term efficacy of the maze procedure concerning cardiac function has not been determined. The aim of this study was to assess long-term results of the maze procedure for left ventricular function in patients with persistent AF associated with mitral valve disease. We analyzed 38 patients who underwent the maze procedure for persistent AF and mitral valve surgery. The cardiothoracic ratio on chest X-ray and the left atrial dimension, left ventricular end-diastolic dimension, left ventricular end-systolic dimension and left ventricular ejection fraction on transthoracic echocardiography were evaluated before and 6 years after the maze procedure. Twenty-two patients maintained sinus rhythm (SR group) and 16 patients had recurrence of permanent AF (AF group) after the maze procedure. Preoperative cardiac function and the methods of mitral surgery were similar between the two groups. At the latest follow-up, left ventricular function tended to be better in the SR group than in the AF group. Cardiovascular events occurred more often in the AF group during follow-up (50 vs. 18%, p < 0.05). This retrospective study revealed that maintaining the sinus rhythm after the maze procedure for patients who underwent mitral valve surgery might be important for preserving better long-term left ventricular function and result in fewer cardiovascular events.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter , Doenças das Valvas Cardíacas/cirurgia , Valva Mitral/cirurgia , Função Ventricular Esquerda , Idoso , Fibrilação Atrial/complicações , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/fisiopatologia , Ablação por Cateter/efeitos adversos , Distribuição de Qui-Quadrado , Feminino , Doenças das Valvas Cardíacas/complicações , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/fisiopatologia , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Valva Mitral/diagnóstico por imagem , Valva Mitral/fisiopatologia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia
13.
Endocrinology ; 153(1): 373-85, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22045661

RESUMO

Gonadotropin-inhibitory hormone (GnIH) is a hypothalamic neuropeptide that inhibits gonadotropin secretion in birds and mammals. To further understand its physiological roles in mammalian reproduction, we identified its precursor cDNA and endogenous mature peptides in the Siberian hamster brain. The Siberian hamster GnIH precursor cDNA encoded two RFamide-related peptide (RFRP) sequences. SPAPANKVPHSAANLPLRF-NH(2) (Siberian hamster RFRP-1) and TLSRVPSLPQRF-NH(2) (Siberian hamster RFRP-3) were confirmed as mature endogenous peptides by mass spectrometry from brain samples purified by immunoaffinity chromatography. GnIH mRNA expression was higher in long days (LD) compared with short days (SD). GnIH mRNA was also highly expressed in SD plus pinealectomized animals, whereas expression was suppressed by melatonin, a nocturnal pineal hormone, administration. GnIH-immunoreactive (-ir) neurons were localized to the dorsomedial region of the hypothalamus, and GnIH-ir fibers projected to hypothalamic and limbic structures. The density of GnIH-ir perikarya and fibers were higher in LD and SD plus pinealectomized hamsters than in LD plus melatonin or SD animals. The percentage of GnRH neurons receiving close appositions from GnIH-ir fiber terminals was also higher in LD than SD, and GnIH receptor was expressed in GnRH-ir neurons. Finally, central administration of hamster RFRP-1 or RFRP-3 inhibited LH release 5 and 30 min after administration in LD. In sharp contrast, both peptides stimulated LH release 30 min after administration in SD. These results suggest that GnIH peptides fine tune LH levels via its receptor expressed in GnRH-ir neurons in an opposing fashion across the seasons in Siberian hamsters.


Assuntos
Glicoproteínas/genética , Glicoproteínas/fisiologia , Hormônios Hipotalâmicos/genética , Hormônios Hipotalâmicos/fisiologia , Phodopus/genética , Phodopus/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Cricetinae , Hormônio Liberador de Gonadotropina/fisiologia , Hormônio Luteinizante/metabolismo , Masculino , Melatonina/farmacologia , Dados de Sequência Molecular , Neuropeptídeos/genética , Neuropeptídeos/farmacologia , Neuropeptídeos/fisiologia , Fotoperíodo , Glândula Pineal/fisiologia , Área Pré-Óptica/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
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