RESUMEN
Squamous cell carcinomas of the oral cavity represent the largest group of malignancies in this area. Currently, there are many prognostic histopathological factors, according to which the maxillofacial surgeon in collaboration with the oncologist is able to determine the prognosis and subsequently also set an appropriate therapy. Nowadays, the squamous cell carcinoma invasion pattern in the area of the "invasive tumor front" seems to be a very important prognostic factor. The invasion pattern is connected to metastatic potential (and to the presence of subclinical microscopic metastases) and may well be the answer to why even early-stage tumors do not respond to standard therapy. That is to say, based on varying invasion pattern, oral cavity squamous cell carcinomas with identical TNM manifest varying clinical behavior and growth tendencies and a varying metastatic potential.
Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Humanos , Neoplasias de la Boca/cirugía , Neoplasias de la Boca/patología , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas de Cabeza y Cuello , Invasividad Neoplásica/patología , Pronóstico , Procesos NeoplásicosRESUMEN
We have investigated expression of skeletal calsequestrin (CSQ1) and fiber type composition in normal and regenerated fast and slow skeletal muscles and in the left heart ventricles of euthyroid (EU), hypothyroid (HY) and hyperthyroid (TH) adult inbred Lewis strain rats. The CSQ1 level was determined by SDS-PAGE followed by Western blot analysis. CSQ1 gene expression was assessed using reverse transcription and subsequent real time polymerase chain reaction. Muscle regeneration was achieved by intramuscular grafting of either soleus or extensor digitorum longus (EDL) from 3- to 4-week-old rats to either EDL or soleus muscle of 2-month-old rats. The fiber type composition was assessed by a stereological method applied to stained muscle cross sections. We found that the protein and mRNA levels for CSQ1 were highest in the EDL muscle, the relative CSQ1 protein levels in the soleus muscle were two times lower and the transcript levels more than 5 times lower compared to the EDL. In the left heart ventricle, protein isoform and CSQ1 transcript were also present, although at protein level, CSQ1 was hardly detectable. TH status increased and HY status decreased the expression of CSQ1 in the EDL, but its relative levels in the soleus and in the heart did not change. The regenerated soleus transplanted into EDL, as well as EDL transplanted into soleus exhibited protein and mRNA levels of CSQ1 corresponding to the host muscle and not to the graft source. TH status increased the percentages of the fastest 2X/D and 2B fibers at the expense of slow type 1 and fast 2A fibers in the EDL and that of fast 2A fibers in the soleus at the expense of slow type 1 fibers. HY status led to converse fiber type changes. We suggest that the observed changes in CSQ1 levels in TH and HY compared to EU rats can be related to fiber type changes caused by alteration of the thyroid status rather than to the direct effect of thyroid hormones on CSQ1 gene expression.