ABSTRACT
BACKGROUND: Increased number of nucleoli (nucleolar organizer regions, NORs) with abnormal shapes and sizes, including small dots, has been used as prognostic tools to evaluate tumor proliferation levels and troublesome borderline lesions. In this study, NOR patterns of skin cancers were performed in the search of a valuable prognostic method to complement other histological procedures. METHODS: Paraffin-embedded tumor tissue was obtained from basal and squamous cell carcinomas, cutaneous malignant melanoma, premalignant lesions, and Skmel-28 human melanoma cells. Slices were dewaxed and AgNOR stained. The patterns were scored and submitted for statistical analyses. RESULTS: All types of cancer cells showed variable numbers of abnormally shaped nucleoli and dot-like structures. Only tumor cells presented four or more nucleoli, with or without dots, while 85% of the normal cells had one single NOR without dots. Most data were statistically significant when compared to normal cells. As a whole, squamous cell carcinoma and malignant melanoma tumor cells had less NOR alterations than basal cell carcinoma (BCC) tumor types. CONCLUSIONS: Changes in the number and shape of nucleoli present in malignant cells could be attributed to increased levels on rDNA transcription on cancer cells, besides abnormal remodeling of chromatin, which could disrupt proper nucleoli association. Increased genetic alterations on malignant basal cells could contribute to impair invasive and migration abilities of BCC tumors.
Subject(s)
Carcinoma, Basal Cell/metabolism , Carcinoma, Squamous Cell/metabolism , Melanoma/metabolism , Nucleolus Organizer Region/metabolism , Precancerous Conditions/metabolism , Skin Neoplasms/metabolism , Carcinoma, Basal Cell/pathology , Carcinoma, Basal Cell/ultrastructure , Cell Line, Tumor , Humans , Melanoma/pathology , Melanoma/ultrastructure , Nucleolus Organizer Region/ultrastructure , Paraffin Embedding , Precancerous Conditions/pathology , Silver Staining , Skin Neoplasms/pathology , Skin Neoplasms/ultrastructureABSTRACT
Increased number of nucleoli (nucleolar organizer regions, NORs) with abnormal shapes and sizes, including small dots, has been used as prognostic tools to evaluate tumor proliferation levels and troublesome borderline lesions. In this study, NOR patterns of skin cancers were performed in the search of a valuable prognostic method to complement other histological procedures.All types of cancer cells showed variable numbers of abnormally shaped nucleoli and dot-like structures. Only tumor cells presented four or more nucleoli, with or without dots, while 85% of the normal cells had one single NOR without dots. Most data were statistically significant when compared to normal cells. As a whole, squamous cell carcinoma and malignant melanoma tumor cells had less NOR alterations than basal cell carcinoma (BCC) tumor types.Changes in the number and shape of nucleoli present in malignant cells could be attributed to increased levels on rDNA transcription on cancer cells, besides abnormal remodeling of chromatin, which could disrupt proper nucleoli association. Increased genetic alterations on malignant basal cells could contribute to impair invasive and migration abilities of BCC tumors.
Subject(s)
Male , Female , Humans , Carcinoma, Basal Cell , Pelvic Neoplasms/immunologyABSTRACT
O presente trabalho analisa a forma craniana de três gêneros de roedores caviíneos. A análise estatística multivariada mostrou que a semelhança de forma craniana é provavelmente devida à convergência com o tamanho nas trajetórias ontogenéticas, estima através da análise de regressäo de escores individuais derivados da análise dos componentes principais dos caracteres morfométricos cranianos
