Abstract: The invention relates to novel cyclic compounds (cyclic peptides), linkers useful as beta-turn promoters in cyclic peptides, and methods for treatment of malignant cells in vitro or in vivo using one or more linear and cyclic peptides. The peptides can act as integrin interaction inhibitors and may be used in the treatment of cancers as monotherapies or in combination with other anti-cancer agents, such as proteasome inhibitors, inhibitors of autophagy, alkylating agents, MEK inhibitors, FAK/PYK2 inhibitors, and EGFR inhibitors. The invention further concerns a method of predicting the binding of a cyclic or linear HYD1 peptide to a cancer cell by assessing overexpression of biomarkers such as CD44, VLA-4 integrin, basigin, CD138 (syndecan 1), NCAM, ICAM1, ICAM3, and CD59.

Abstract: The subject invention pertains to compositions and methods for treatment of malignancies and inhibiting the growth of cancer cells, such as multiple myeloma and other hematologic malignancies, using HYD1 peptides. Other aspects of the invention are directed to methods for selection of agents useful in the treatment of malignancies and inhibiting the growth of cancer cells. Further aspects of the invention include methods for determining whether a cancer is sensitive or resistant to treatment with HYD1 peptides based on the presence of certain biomarkers, such as ?4 integrin and CD44 expression.