An insulin-like growth factor-II intronic variant affects local DNA conformation and ovarian cancer survival.

Insulin-like growth factor-II (IGF-II) may be a prognostic marker in ovarian cancer, and its intronic single nucleotide polymorphism (SNP) rs4320932 has been associated with risk of the disease. We determined whether rs4320932 is associated with IGF-II expression and patient survival in ovarian cancer, and explored whether the SNP variation affects DNA conformation both in the absence of and presence of carboplatin. IGF-II genotype (rs4320932) and phenotype were analyzed in 212 primary invasive epithelial ovarian cancer tissue samples with Taqman® SNP genotyping assays, quantitative reverse transcription-polymerase chain reaction and commercial enzyme-linked immunosorbent assay. DNA conformation was evaluated by circular dichroism (CD) spectra. Kaplan-Meier survival curves and Cox proportional hazard regression models were used to analyze the SNP associations with patient survival. The C allele of rs4320932, previously associated with decreased risk of ovarian cancer development, was here associated with significantly elevated risks of relapse (Ptrend = 0.0002) and death (Ptrend = 0.0006), remaining significant in multivariate analyses. The adjusted hazard ratios were 3.05 (95% confidence interval [CI]: 1.47-6.37) for relapse and 3.28 (95% CI: 1.64-6.57) for death, respectively. The variant was also significantly associated with chemotherapy response, but not with other clinicopathologic variables or with IGF-II expression. DNA with genotypes TT and CC had distinct CD spectra in both the absence of and presence of carboplatin. These findings suggest that the intronic SNP rs4320932 affects patient survival and chemotherapy response via alteration of DNA conformation, but not through regulation of IGF-II expression. This novel finding may have implications in individualized medicine for the design of specific molecules targeting DNA of specific conformations.

Dynamic changes of circulating soluble PD-1/PD-L1 and its association with patient survival in immune checkpoint blockade-treated melanoma.

Immune checkpoint PD-1 and its ligand PD-L1 lead to T cell exhaustion, and a high level of circulating soluble PD-L1 at baseline indicates a poor prognosis in melanoma and other solid tumor types. Here we show that the dynamic changes of circulating soluble PD-1 and PD-L1 across the course of immune checkpoint blockades (ICBs) and their changes associate with patient survival in melanoma in a retrospective study. A high change of soluble PD-L1 level at a time-point but not PD-1 significantly increased the mortality, whereas a high change of soluble PD-1/PD-L1 ratio significantly reduced the mortality. After the initial immunotherapy, both soluble PD-1 and PD-L1 increased. However, the change pattern of soluble PD-L1 level was particularly dependent on patients' survival status. These findings indicate that the magnitudes of circulating soluble PD-L1 and PD-1/PD-L1 ratio changes over the time may reflect the patients' response to ICBs or the progression of the disease and predict the survival in melanoma patients treated with ICBs.