Anti-DKK4 monoclonal antibody, clone FQS8978(3)

Further elucidation of the molecular mechanisms underlying lung cancer (LC) is essential for the development of new effective therapeutic agents. Recently, involvement of Wnt antagonists in oncogenesis has been demonstrated in several cancers. The investigation of their contribution to lung carcinogenesis is still under investigation. We aimed to investigate whether there is a susceptibility or preventive effect of Wnt antagonist gene polymorphisms on the development and/or prognosis of LC. We investigated 110 LC patients and 160 controls. Single-nucleotide polymorphisms of Wnt antagonist genes including DKK2 (rs17037102), DKK3 (rs3206824), DKK3 intron4 G/C (rs7396187), DKK4 (rs2073664), and sFRP4 (rs1802074) were analyzed using nested polymerase chain reaction and restriction fragment length polymorphism. Results showed that patients with DKK3 AA compared with controls have a decreased risk of LC (adjusted for smoking habit, body mass index, and familial history) (P = 0.02; odds ratio [OR],0.08; 95% confidence interval [95% CI], 0.01-0.7). It was found that, for sFRP4 polymorphism, patients with GG and GA genotypes versus AA genotype controls showed a decreased risk for LC (P = 0.01; [OR, 0.19; 95% CI, 0.05-0.73 for GG genotype]; [OR = 0.18, 95% CI, 0.04-0.72 for GA genotype]). In addition, a decreased risk of LC was also found for the genotype combination of DKK3 (rs3206824) GG and sFRP4 AG + GG (P = 0.004; OR, 0.12; 95% CI, 0.02-0.58). We suggest that these 2 polymorphisms have a protective effect on LC in this study.

Altered glucose uptake and metabolism is the key characteristic of cancer cells including hepatocellular carcinoma (HCC). However, role of glucose availability in chemotherapeutic outcome of HCC is unclear. The present study investigates the effect of glucose facilitated sensitization of HCC cells towards doxorubicin (DOX) and sorafenib (SORA). In HCC cells, we observed that hyperglycemic culture condition (HG) is associated with increased sensitivity towards DOX and SORA. P-glycoprotein (P-gp), a transporter involved in drug efflux, was elevated in HCC cells in NG, rendering them less susceptible to DOX and SORA. Further, this study demonstrated that knockdown of dickkopf protein 4 (DKK4), a Wnt antagonist protein, causes enhanced glucose uptake and reduction in P-gp level rendering HCC cells in NG sensitive to DOX and SORA. Moreover, HG elevates the level of intracellular reactive oxygen species (ROS), which regulates P-gp. Alteration in intracellular ROS did not directly affect regulation of DKK4 in HCC cells. Functional assays suggest that alterations in DKK4 and P-gp level in HCC cells are dependent on glucose availability and changes in ROS level because of enhanced glucose utilization, respectively. Collectively, the present study highlights direct involvement of glucose-induced ROS, DKK4 and P-gp in altering the sensitivity of HCC cells towards DOX and SORA.