CREB-binding protein (CBP) gene family regulates planarian survival and stem cell differentiation

In developmental biology, the regulation of stem cell plasticity and differentiation remains an open question. CBP(CREB-binding protein)/p300 is a conserved gene family that functions as a transcriptional co-activator and plays important roles in a wide range of cellular processes, including cell death, the DNA damage response, and tumorigenesis. The acetyl transferase activity of CBPs is particularly important, as histone and non-histone acetylation results in changes in chromatin architecture and protein activity that affect gene expression. Many studies have described the conserved functions of CBP/p300 in stem cell proliferation and differentiation. The planarian Schmidtea mediterranea is an excellent model for the in vivo study of the molecular mechanisms underlying stem cell differentiation during regeneration. However, how this process is regulated genetically and epigenetically is not well-understood yet. We identified 5 distinct Smed-cbp genes in S. mediterranea that show different expression patterns. Functional analyses revealed that Smed-cbp-2 appears to be essential for stem cell maintenance. On the other hand, the silencing of Smed-cbp-3 resulted in the growth of blastemas that were apparently normal, but remained largely unpigmented and undifferentiated. Smed-cbp-3 silencing also affected the differentiation of several cell lineages including neural, epidermal, digestive, and excretory cell types. Finally, we analysed the predicted interactomes of CBP-2 and CBP-3 as an initial step to better understand their functions in planarian stem cell biology. Our results indicate that planarian cbp genes play key roles in stem cell maintenance and differentiation.

Prognostic factors in mobile tongue and floor of mouth carcinoma

This study identifies significant prognostic factors in squamous cell carcinomas of the anterior tongue and floor of mouth. It is clear that the TMN staging system does not account for other important variables that affect tumor prognosis. Tumor thickness and the presence of perineural invasion and intralymphatic tumor emboli should be examined in all resected tumors. Tumor thickness, tumor size, and perineural invasion all have an impact on survival and must be considered in treatment plans. Tumors measuring between 2 mm and 3 mm may or may not have metastases and further evaluation of this group needs to be done. Most importantly, the data in this study supports a multiinstitutional prospective evaluation of pathology specimens. Precise guidelines must be established for handling of the specimen, which must then be evaluated for the variables mentioned above. In this way, more definitive conclusions can be reached in the management of tumors of the anterior tongue and floor of mouth.