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.

Asparagine synthetase and G-protein coupled estrogen receptor are critical responders to nutrient supply in KRAS mutant colorectal cancer.

The nutrient status of the tumor microenvironment has major impacts on cell growth. Under nutrient depletion, asparagine synthetase (ASNS)-mediated asparagine production increases to sustain cell survival. G protein-coupled estrogen receptor-1 (GPER1) signaling converges via cAMP/PI3K/AKT with KRAS signaling to regulate ASNS expression. However, the role of GPER1 in CRC progression is still debated, and the effect of nutrient supply on both ASNS and GPER1 relative to KRAS genotype is not well understood. Here, we modeled a restricted nutrient supply by eliminating glutamine from growing cancer cells in a 3D spheroid model of human female SW48 KRAS wild-type (WT) and KRAS G12A mutant (MT) CRC cells, to examine effects on ASNS and GPER1 expression. Glutamine depletion significantly inhibited cell growth in both KRAS MT and WT cells; however, ASNS and GPER1 were upregulated in KRAS MT compared to WT cells. When nutrient supply was adequate, ASNS and GPER1 were not altered between cell lines. The impact of estradiol, a ligand for GPER1, was examined for any additional effects on cell growth. Under glutamine deplete conditions, estradiol decreased the growth of KRAS WT cells but had no effect on KRAS MT cells; estradiol had no additive or diminutive effect on the upregulation of ASNS or GPER1 between the cell lines. We further examined the association of GPER1 and ASNS levels with overall survival in a clinical colon cancer cohort of The Cancer Genome Atlas. Both high GPER1 and ASNS expression associated with poorer overall survival for females only in advanced stage tumors. These findings suggest that KRAS MT cells have mechanisms in place that respond to decreased nutrient supply, typically observed in advanced tumors, by increasing the expression of ASNS and GPER1 to drive cell growth. Furthermore, KRAS MT cells are resistant to the protective effects of estradiol under nutrient deplete conditions. ASNS and GPER1 may therefore be potential therapeutic targets that can be exploited to manage and control KRAS MT CRC.

Reactivation of latent HIV-1 in latently infected cells by coumarin compounds: Hymecromone and ScoparoneReactivation of Latent HIV-1 in Latently Infected Cells by Coumarin Compounds: Hymecromone and Scoparone.

BACKGROUND: Current antiretroviral therapy (ART) cannot cure HIV-1 infection due to the presence of latent viral reservoirs. The "shock and kill" strategy is a promising approach to eliminate the viral reservoir. However, there are various limits existing in current latency-reversing agents, searching for new activators are urgently needed. OBJECTIVE: The present study aimed at investigating the ability of hymecromone and scoparone for activating HIV-1 from latent reservoirs. METHODS: Jurkat T cell model of HIV-1 latently were used to evaluate the effect of hymecromone and scoparone. The percentage of green florescence protein expression as a marker for reactivation of HIV-1 promoter was measured via FACScan. The expression of CD25 and CD69 in human peripheral blood mononuclear cells was measured by flow cytometry at 72 h post-treatment with hymecromone or scoparone or prostratin using antibodies against CD25 and CD69. RESULTS: Hymecromone and scoparone can induce HIV-1 LTR reactivation in a dose and timedependent. We further show that hymecromone and scoparone can reactivate latent virus without inducing the activation of global T cells. We also found that scoparone acts by NF-&kgr;B signal pathway. CONCLUSION: Hymecromone and scoparone can effectively reactivate latent HIV-1 with low cellular toxicity, indicating hymecromone and scoparone might be potential drugs for HIV-1 reservoir eradication strategies in the future.