The genesis and progression of cancer are exceptionally complex. The incidence rate of diverse cancer types is increasing alarmingly around the world. The major problems in the development of cancer drugs are chemo-resistance and tumor recurrence. Conventional therapies have proved unsuccessful in eliminating tumors completely.

Abnormal singaling has been implicated in tumor formation, including the phosphoinositide 3-kinase (PI3K)/Akt, mammalian target of rapamycin (mTOR), Wnt/β-Catenin, mitogen-activated protein kinase (MAPK), signal transducer and activator of transcription 3 (STAT3), and notch signaling pathways. Targeted chemotherapy has been shown to be successful in treating certain malignancies. However, its efficacy has often been limited by drug resistance and side effects on normal tissues and cells. Immunotherapy is one promising area that has attracted much interest. Along with abnormal tumor signaling pathways, targeting cancer stem cells and microRNAs are playing key roles in cancer drug development. It is well known that cancer stem cells are the major reason for the drug resistance and tumor recurrence. MicroRNAs regulate multiple key signaling pathways that promote tumorigenesis.

This Special Issue aims to collate original research and review articles that describe some of these promising anticancer targets, including (PI3K)/Akt, mTOR, Wnt/β-Catenin, MAPK, STAT3, and notch signaling pathways along with cancer stem cells, microRNAs, and other key targets. In addition, articles describing promising drug candidates of natural and synthetic origin under various phases of clinical trials are also welcome.

Potential topics include but are not limited to the following:

• Notch signaling and its regulation in cancer
• The role of oncomirs in the regulation of various cancers
• Cancer stem cells and their role in chemo-resistance
• Immunotoxins and immunotherapy
• Promising natural agents targeting microRNAs in cancer
• Exosome-based therapy to target cancer stem cells
• Potential drugs targeting the Hedgehog pathway for the treatment of cancer
• Antibody-cytokine fusion proteins: a novel class of biopharmaceuticals for the therapy of cancer
• The centrosome: a future candidate in cancer therapy
• Sphingosine kinase as a target to treat gastrointestinal cancers
• mTOR pathway inhibitors as anticancer agents
• CXCR4 and CCR7 targets in cancer therapy
• STAT3 inhibitors for the treatment of inflammation-driven cancers
• Plant-derived natural products and synthetic compounds acting on key signaling pathways in cancer