Qualitative and Quantitative Studies of Polygene Proteins Expression in Esophageal Precancerous Lesions and Esophageal Carcinoma

Objective： To examine the expressions of MDM2, P53 and P27 proteins in chronic esophagitis, para-cancer mucosa and esophageal carcinoma. Methods： Immunohistochemistry was used to detect the expressions of MDM2, P53 and P27 proteins in forty-seven patients suffering from chronic esophagitis and eighty-five cases of esophageal carcinoma and corresponding para-cancer mucosa. Flow cytometry（（FCM） was applied to detect the quantities of these proteins expressed in fresh tissues of 48 cases of esophageal cancer and their para-cancer tissues and 24 cases of relative normal mucosa at the surface of cutting edge. Results： Immunohistochemistry results showed that the expressions of the three studied proteins were very similar in the epithelia of chronic esophagitis and para-cancer mucosa （P〉0.05）. Both the qualitative and quantitative studies displayed that the P53 protein had no expression and its accumulations would appear only in the early stages of esophagus canceration while the MDM2 and P27 proteins had different degrees of expressions in cases of normal esophageal mucosa. MDM2 protein markedly increased in the advanced stages of esophageal canceration. A quantitative study showed that the expression of P27 protein had a linearity of decreasing tendency （F=9.132, P=0.002） in the course of esophageal canceration. Conclusion： Chronic esophagitis may be a precancerous lesion. Owing to the changes of the P53 and P27 proteins, we can also conclude that these occur in the early stages of esophagus oncogenesis, however the changes of MDM2 expression may occur in the advanced stage of esophageal canceration.

ANTIBODY TO ONCOGENE PROTEIN PRODUCT AND ITS CONJUGATE WITH RICIN A-CHAIN

The proteins encoded by oncogene were thought to be tumor associated antigen. The protein P110 in MGC803, a human gastric cancer cell line, was purified as immunogen. The IgY to the gastric cancer was extracted from eggs laid by immunized hen. The IgY could react immunohistochemically with gastric cancers. Positive staining rates of PAF were 80% in gastric cancers and markedly higher than in cancers of other organs and normal gastric tissue. The IgY-Ricin A was synthesized by the IgY conjugated with Ricin A- chain. TCID50 of MGC803 treated by the IgY-Ricin A was 0. 01 mg/ml and markedly lower than other cell. These results showed the IgY-Ricin A were able to react with gastric cancers selectively.

Targeting the“undruggable”cancer driver genes:Ras,myc,and tp53

The term“undruggable”is to describe molecules that are not targetable or at least hard to target pharmacologically.Unfortunately,some targets with potent oncogenic activity fall into this category,and currently little is known about how to solve this problem,which largely hampered drug research on human cancers.Ras,as one of the most common oncogenes,was previously considered“undruggable”,but in recent years,a few small molecules like Sotorasib(AMG-510)have emerged and proved their targeted anti-cancer effects.Further,myc,as one of the most studied oncogenes,and tp53,being the most common tumor suppressor genes,are both considered“undruggable”.Many attempts have been made to target these“undruggable”targets,but little progress has been made yet.This article summarizes the current progress of direct and indirect targeting approaches for ras,myc,two oncogenes,and tp53,a tumor suppressor gene.These are potential therapeutic targets but are considered“undruggable”.We conclude with some emerging research approaches like proteolysis targeting chimeras(PROTACs),cancer vaccines,and artificial intelligence(AI)-based drug discovery,which might provide new cues for cancer intervention.Therefore,this review sets out to clarify the current status of targeted anti-cancer drug research,and the insights gained from this review may be of assistance to learn from experience and find new ideas in developing new chemicals that directly target such“undruggable”molecules.