Assays for predicting and monitoring responses to lung cancer immunotherapy

Immunotherapy has become a key strategy for cancer treatment, and two immune checkpoints, namely, programmed cell death 1(PD-1) and its ligand(PD-L1), have recently emerged as important targets. The interaction blockade of PD-1 and PD-L1 demonstrated promising activity and antitumor efficacy in early phase clinical trials for advanced solid tumors such as non-small cell lung cancer(NSCLC). Many cell types in multiple tissues express PD-L1 as well as several tumor types, thereby suggesting that the ligand may play important roles in inhibiting immune responses throughout the body. Therefore, PD-L1 is a critical immunomodulating component within the lung microenvironment, but the correlation between PD-L1 expression and prognosis is controversial. More evidence is required to support the use of PD-L1 as a potential predictive biomarker. Clinical trials have measured PD-L1 in tumor tissues by immunohistochemistry(IHC) with different antibodies, but the assessment of PD-L1 is not yet standardized. Some commercial antibodies lack specificity and their reproducibility has not been fully evaluated. Further studies are required to clarify the optimal IHC assay as well as to predict and monitor the immune responses of the PD-1/PD-L1 pathway.

Systemic treatment in EGFR-ALK NSCLC patients:second line therapy and beyond

Lung cancer is the most frequently diagnosed cancer and a leading cause of cancer mortality worldwide, with adenocarcinoma being the most common histological subtype. Deeper understanding of the pathobiology of non-small cell lung cancer(NSCLC) has led to the development of small molecules that target genetic mutations known to play critical roles in progression to metastatic disease and to influence response to targeted therapies. The principle goal of precision medicine is to define those patient populations most likely to respond to targeted therapies. However, the cancer genome landscape is composed of relatively few "mountains" [representing the most commonly mutated genes like KRAS, epidermal growth factor(EGFR), and anaplastic lymphoma kinase(ALK)] and a vast number of "hills"(representing low frequency but potentially actionable mutations). Low-frequency lesions that affect a druggable gene product allow a relatively small population of cancer patients for targeted therapy to be selected.

Identification of a novel PAK1 inhibitor to treat pancreatic cancer

Pancreatic cancer is one of the most aggressive cancers with poor prognosis and a low 5-year survival rate.The family of P21-activated kinases(PAKs)appears to modulate many signaling pathways that contribute to pancreatic carcinogenesis.In this work,we demonstrated that PAK1 is a critical regulator in pancreatic cancer cell growth.PAK1-targeted inhibition is therefore a new potential therapeutic strategy for pancreatic cancer.Our small molecule screening identified a relatively specific PAK1-targeted inhibitor,CP734.Pharmacological and biochemical studies indicated that CP734 targets residue V342 of PAK1 to inhibit its ATPase activity.Further in vitro and in vivo studies elucidated that CP734 suppresses pancreatic tumor growth through depleting PAK1 kinase activity and its downstream signaling pathways.Little toxicity of CP734 was observed in murine models.Combined with gemcitabine or 5-fluorouracil,CP734 also showed synergistic effects on the anti-proliferation of pancreatic cancer cells.All these favorable results indicated that CP734 is a new potential therapeutic candidate for pancreatic cancer.