Title:Mechanisms of Resistance to Chemotherapy in Gastric Cancer
Volume: 16
Issue: 3
Author(s): J.J.G. Marin, R. Al-Abdulla, E. Lozano, O. Briz, L. Bujanda, J. M. Banales and R.I.R. Macias
Affiliation:
Keywords:
Antitumor drugs, chemoresistance, stomach, treatment, tumor.
Abstract: Although surgical resection is the standard curative therapy for gastric cancer, these tumors are often
diagnosed at an advanced stage, when surgery is not recommended. Alternative treatments such as radiotherapy
and chemotherapy achieve only very modest results. There is therefore an urgent need to advance in this field of
oncologic gastroenterology. The poor response of gastric cancer to chemotherapy is usually due to a combination
of mechanisms of chemoresistance (MOC), which may include a reduction in drug uptake (MOC-1a), enhanced
drug efflux (MOC-1b), a reduced proportion of active agents in tumor cells due to a reduction in pro-drug
activation or an enhancement in drug inactivation (MOC-2), changes in the expression/function of the molecular targets of anticancer
drugs (MOC-3), an enhanced ability of cancer cells to repair anticancer drug-induced DNA damage (MOC-4), and decreased
expression/function of pro-apoptotic factors or up-regulation of anti-apoptotic genes (MOC-5). Two major goals of modern
pharmacology aimed at overcoming this situation are the prediction of a lack of response to chemotherapy and the identification of the
underlying mechanisms accounting for primary or acquired refractoriness to anticancer drugs. These are important issues if we are to
select the best pharmacological regime for each patient and develop novel strategies to overcome chemoresistance. The present review
reports updated information regarding the mechanisms of chemoresistance (from MOC-1 to MOC-5) in gastric cancer, the advances
made in the prediction of the failure of chemotherapeutic treatment, and novel strategies based on gene therapy currently being developed
to treat these tumors.
