scc-1

SERPINB3, also known as SCCA-1, belongs to the serpin family. Serpins are a group of proteins with similar structures that were first identified as a set of proteins able to inhibit proteases. The acronym serpin was originally coined because many serpins inhibit chymotrypsin-like serine proteases. SERPINB3 is expressed in some hepatocellular carcinoma (at protein level). Its expression is closely related to cellular differentiation in both normal and malignant squamous cells. It seems to also be secreted in plasma by cancerous cells but at a low level. SERPINB3 significantly attenuates apoptosis by contrasting cytochrome c release from the mitochondria and by antichemotactic effect for NK cells. It may act as a protease inhibitor to modulate the host immune response against tumor cells and may be involved in the malignant behavior of squamous cell carcinoma cells.

Tumor necrosis factor (TNF)-alpha-induced protein 8 (TNFAIP8) family is a newly identified protein with vital roles in maintaining immune homeostasis. Tumor necrosis factor-alpha-inducible protein 8 (TNFAIP8) is a TNF-alpha inducible anti-apoptotic protein with multiple roles in tumor growth and survival. by the creation of cellular autophagy events, TNFAIP8 promotes cell survival and drug resistance in prostate cancer cells. TNFAIP8 regulates Hippo pathway through interacting with LATS1 to promote cell proliferation and invasion in lung cancer. TNFAIP8 may serve as a candidate biomarker for poor prognosis and a target for new therapies.

Small ubiquitin-like modifier protein (SUMO) modification is a highly dynamic process, catalyzed by SUMO-specific activating (E1), conjugating (E2) and ligating (E3) enzymes, and reversed by a family of SUMO-specific proteases (SENPs). Small ubiquitin-like modifier 1 (SUMO1) is a member of the superfamily of ubiquitin-like proteins. Despite its structural similarity with ubiquitin, SUMO1 does not seem to play any role in protein degradation. SUMO1 plays an important role in modulation of NOX activity required for ROS generation. SUMO1 haploinsufficiency results in cleft lip and palate in animal models. SUMO1 gene variation in human non-syndromic cleft lip with or without cleft palate (NSCLP) development. SUMO-1 may be useful as a novel target for therapy in oral squamous cell carcinoma (SCC) as well as a clinical indicator for tumor recurrence together with Mdm2.

DEP1 / PTPRJ (Receptor-type tyrosine-protein phosphatase eta) is a member of the protein tyrosine phosphatase (PTP) family. PTPs are known to be signaling molecules that regulate a variety of cellular processes, including cell growth, differentiation, mitotic cycle, and oncogenic transformation. DEP1 / PTPRJ possesses an extracellular region containing five fibronectin type III repeats, a single transmembrane region, and a single intracytoplasmic catalytic domain, and thus represents a receptor-type PTP. DEP1 / PTPRJ is present in all hematopoietic lineages, and was shown to negatively regulate T cell receptor signaling possibly through interfering with the phosphorylation of Phospholipase C Gamma 1 and Linker for Activation of T Cells. This protein can also dephosphorylate the PDGF beta receptor, and may be involved in UV-induced signal transduction. In stable MCF-7 cell lines, induction of DEP-1 expression inhibited breast cancer cell growth by 5-10-fold. These data describe PTPs expressed and regulated in breast cancer cell lines during differentiation and identify one PTP, DEP-1, that inhibits the growth of breast cancer cells in vitro.