Anti-EGF (C-terminal) polyclonal antibody

Ubiquilin (UBQLN) proteins are involved in diverse cellular processes like endoplasmic reticulum-associated degradation, autophagy, apoptosis, and epithelial-to-mesenchymal transition. UBQLNs interact with a variety of substrates, including cell surface receptors, transcription factor regulators, proteasomal machinery proteins, and transmembrane proteins. In addition, previous work from our lab shows that UBQLN1 interacts with insulin-like growth factor receptor family members (IGF1R, IGF2R, and INSR) and this interaction regulates the activity and proteostasis of IGFR family members. We wondered whether UBQLN proteins could also bind and regulate additional receptor tyrosine kinases. Thus, we investigated a link between UBQLN and the oncogene epidermal growth factor receptor (EGFR) in lung adenocarcinoma cells. Loss of UBQLN1 occurs at high frequency in human lung cancer patient samples and we have shown that the loss of UBQLN1 is capable of altering processes involved in cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition in lung adenocarcinoma cell lines. Here, we present data that loss of UBQLN1 resulted in increased turnover of total EGFR while increasing the relative amount of phosphorylated EGFR in lung adenocarcinoma cells, especially in the presence of its ligand EGF. Furthermore, the loss of UBQLN1 led to a more invasive cell phenotype as manifested by increased proliferation, migration, and speed of movement of these lung adenocarcinoma cells. Taken together, UBQLN1 regulates the expression and stability of EGFR in lung cancer cells.

The development of neuroprotective drugs has proven to be extremely difficult because of the blood-brain barrier. Intranasal administration is thought to transport the drug from the nasal cavity along the olfactory and trigeminal nerves to the brain, thus bypassing the blood-brain barrier. However, macromolecular protein drugs have low delivery efficiency via this route in general. We hypothesized that an innocuous cholera toxin-like chimeric protein could better enhance the efficiency of protein delivery through the intranasal route. To test this hypothesis, we designed an enhanced green fluorescent protein (EGFP) chimera to evaluate the effect of the cholera toxin (CT) as a carrier for drug delivery into the brain. Then, the EGFP was replaced with epidermal growth factor (EGF) in the chimeric protein, and the therapeutic effect of the new chimeric protein was studied in an LPS-induced neuritis mouse model. The results suggest that the CT-like chimeric protein can bypass the blood-brain barrier and enter the brain in approximately 30 min. This EGF chimeric protein can effectively protect the spatial cognitive ability of and confer anti-anxiety protection to mice. The results indicate that cholera toxin-like chimeric proteins are potential tools for effectively delivering macromodecular drugs into the brain through intranasal administration.