Factors that may influence polymorphous low-grade adenocarcinoma growth

Abstract

There is mounting evidence on the importance of some biological processes in tumor growth, such as vascular supply, apoptosis, autophagy, and senescence. We have investigated these processes in polymorphous low-grade adenocarcinoma (PLGA), in an attempt to identify those that are relevant for this particular lesion. We analyzed 31 cases of PLGA using immunohistochemistry to antibodies against CD34 and CD105 to detect blood vessels; against D2-40 to detect lymphatic vessels; against Bax, Bcl-2, and survivin to explore cell apoptosis; and against Beclin and LCB3 to investigate autophagy and against p21 and p16 to assess senescence. Our results showed that PLGA growth does not depend on newly formed vessels but only on preexisting vasculature. Furthermore, PLGA is promoted by autophagy, sustained by both anti-apoptotic and anti-senescence signals, and stimulated by Bcl-2 and survivin.

Role of apoptotic, autophagic and senescence pathways in minor salivary gland adenoid cystic carcinoma

“…In conclusion, ACC has its growth based on autophagy, anti-apoptotic and anti-senescense mechanisms, as recently reported for Polymorphous adenocarcinoma [12], suggesting common disrupted pathways for several slow-growing salivary gland malignancies.…”

“…Some tumour suppressor pathways involved in cell cycle control, such as cyclin-dependent kinase inhibitors p21 and p16, are also deregulated in human cancers [22]. Despite not being specific markers of senescence, p21 plays a transient inhibitory role on pRb while p16 ensures a state of permanent pRb hypophosphorilation [12]. We noted a predominant strong and intense expression of p21 contrasting with complete negativity for p16.…”

Molecular and Cellular Modelling of Salivary Gland Tumors Open New Landscapes in Diagnosis and Treatment

“…This cellular mechanism allows survival in hypoxic conditions and nutrients depletion, and it is linked to the expression of the autophagosome proteins Beclin and LC3B. In parallel, pro-survival markers (such as BCL2 and Survivin) and growth factors such as FGF2 and PDGFα and PDGFβ are overexpressed, while senescence signals are low (e.g., expression of p21 and p16) [ 102 , 103 ].…”

Autophagy and salivary gland cancer: A putative target for salivary gland tumors

“…Both autophagy markers Beclin-1 and LC3 were expressed in this rare type of tumor, suggesting that PAC autophagy is a key mechanism to support tumor growth. 84…”