Increased density of tumor-associated macrophages is associated with decreased survival in advanced thyroid cancer.

Thyroid cancers are infiltrated with tumor-associated macrophages (TAMs), yet their role in cancer progression is not known. The objectives of this study were to characterize the density of TAMs in well-differentiated (WDTC), poorly differentiated (PDTC), and anaplastic thyroid cancers (ATC) and to correlate TAM density with clinicopathologic parameters. Immunohistochemistry was performed on tissue microarray sections from WDTC (n=33), PDTC (n=37), and ATC (n=20) using macrophage-specific markers. Electronic medical records were used to gather clinical and pathologic data. Follow-up information of PDTC patients was available for 0-12 years. In total, 9 out of 33 WDTC (27%), 20 out of 37 PDTC (54%), and 19 out of 20 ATC (95%) had an increased density of CD68(+) TAMs (> or = 10 per 0.28 mm(2); WDTC versus PDTC, P=0.03; WDTC versus ATC, P<0.0001; PDTC versus ATC, P<0.002). Increased TAMs in PDTC was associated with capsular invasion (P=0.034), extrathyroidal extension (P=0.009), and decreased cancer-related survival (P=0.009) compared with PDTC with a low density of TAMs. In conclusion, the density of TAMs is increased in advanced thyroid cancers. The presence of a high density of TAMs in PDTC correlates with invasion and decreased cancer-related survival. These results suggest that TAMs may facilitate tumor progression. As novel therapies directed against thyroid tumor cell-specific targets are being tested, the potential role of TAMs as potential modulators of the thyroid cancer behavior will need to be considered.

MicroRNAs: nova classe de reguladores gênicos envolvidos na função endócrina e câncer / MicroRNAs: novel class of gene regulators involved in endocrine function and cancer / MicroRNAs: novel class of gene regulators involved in endocrine function and cancer

MicroRNAs (miRNAs) representam uma nova classe de RNAs endógenos de ~22 nucleotídeos, que atuam como silenciadores pós-transcricionais, inibindo a tradução de RNAs mensageiros-alvo. Descobertos há pouco mais de uma década em Caenorhabditis elegans, os miRNAs são hoje reconhecidos como reguladores fundamentais da expressão gênica em plantas e animais. Até o momento, identificaram-se 462 genes de miRNA no genoma humano e estima-se que esse número supere 1000 miRNAs distintos. Análises bioinformáticas indicam que um único miRNA atue em diversos RNAs mensageiros, influenciando múltiplas vias de sinalização concomitantemente e apresentando enorme potencial regulatório. Apesar da biologia dos miRNAs ser ainda pouco entendida, essas moléculas já foram relacionadas a diversos processos biológicos. Além disso, a expressão anômala destes pequenos RNAs tem sido associada a diferentes patologias humanas, inclusive aquelas relacionadas ao sistema endócrino e câncer.

MicroRNAs (miRNAs) represent a novel class of endogenous ~22-nucleotide RNAs that negatively regulate gene expression by inhibiting translation of target RNAs. Discovered just over a decade ago in Caenorhabditis elegans, miRNAs are now recognized as one of the major regulatory gene families in plants and animals. In the human genome, 462 miRNA genes have been discovered and the estimated number of miRNAs is as high as 1000. Bioinformatics analysis indicated that a unique miRNA acts on several mRNA, influencing multiple signaling pathways concomitantly, thus presenting enormous regulatory potential. Although the biology of miRNAs is not well understood, recent evidences have linked these molecules to diverse biological processes. Moreover, aberrant expression of miRNAs has been associated to human disease, including that related to the endocrine system and cancer.

[MicroRNAs: novel class of gene regulators involved in endocrine function and cancer]. / MicroRNAs: nova classe de reguladores gênicos envolvidos na função endócrina e câncer.

MicroRNAs (miRNAs) represent a novel class of endogenous approximately 22-nucleotide RNAs that negatively regulate gene expression by inhibiting translation of target RNAs. Discovered just over a decade ago in Caenorhabditis elegans, miRNAs are now recognized as one of the major regulatory gene families in plants and animals. In the human genome, 462 miRNA genes have been discovered and the estimated number of miRNAs is as high as 1000. Bioinformatics analysis indicated that a unique miRNA acts on several mRNA, influencing multiple signaling pathways concomitantly, thus presenting enormous regulatory potential. Although the biology of miRNAs is not well understood, recent evidences have linked these molecules to diverse biological processes. Moreover, aberrant expression of miRNAs has been associated to human disease, including that related to the endocrine system and cancer.