Abnormal structural and molecular changes in malignant tissues were thoroughly investigated and utilized to target
tumor cells, hence rescuing normal healthy tissues and lowering the unwanted side effects as non-specific cytotoxicity. Various
ligands for
cancer cell specific markers have been uncovered and inspected for directional delivery of the anti-
cancer drug to the
tumor site, in addition to diagnostic applications. Over the past few decades research related to the
ligand targeted
therapy (LTT) increased tremendously aiming to treat various pathologies, mainly
cancers with well exclusive markers. Malignant
tumors are known to induce elevated levels of a variety of
proteins and
peptides known as
cancer "markers" as certain
antigens (e.g., Prostate specific membrane
antigen "PSMA",
carcinoembryonic antigen "CEA"), receptors (
folate receptor, somatostatin receptor),
integrins (
Integrin αvβ3) and cluster of differentiation molecules (CD13). The choice of an appropriate marker to be targeted and the design of effective
ligand-drug conjugate all has to be carefully selected to generate the required
therapeutic effect. Moreover, since some
tumors express aberrantly high levels of more than one marker, some approaches investigated targeting
cancer cells with more than one
ligand (dual or multi targeting). We aim in this review to report an update on the
cancer-specific receptors and the vehicles to deliver cytotoxic drugs, including recent advancements on
nano delivery systems and their implementation in targeted
cancer therapy. We will discuss the advantages and limitations facing this approach and possible solutions to mitigate these obstacles. To achieve the said aim a literature search in electronic data bases (PubMed and others) using keywords "
Cancer specific receptors,
cancer specific antibody,
tumor specific
peptide carriers,
cancer overexpressed
proteins,
gold nanotechnology and
gold nanoparticles in
cancer treatment" was carried out.