Suberoylanilide hydroxamic acid (SAHA) is a well-known histone deacetylase (HDAC) inhibitor and has been used as practical therapy for breast cancer and non-small cell lung cancer (NSCLC). It is previously demonstrated that SAHA treatment could extensively change the profile of acetylome and proteome in cancer cells. However, little is known about the impact of SAHA on other protein modifications and the crosstalks among different modifications and proteome, hindering the deep understanding of SAHA-mediated cancer therapy. In this work, by using SILAC technique, antibody-based affinity enrichment and high-resolution LC-MS/MS analysis, we investigated quantitative proteome, acetylome and ubiquitylome as well as crosstalks among the three datasets in A549 cells toward SAHA treatment. In total, 2968 proteins, 1099 acetylation sites and 1012 ubiquitination sites were quantified in response to SAHA treatment, respectively. With the aid of intensive bioinformatics, we revealed that the proteome and ubiquitylome were negatively related upon SAHA treatment. Moreover, the impact of SAHA on acetylome resulted in 258 up-regulated and 99 down-regulated acetylation sites at the threshold of 1.5 folds. Finally, we identified 55 common sites with both acetylation and ubiquitination, among which ubiquitination level in 43 sites (78.2%) was positive related to acetylation level.

e Nucleos(t)ide analogues rarely result in a durable off-treatment response in chronic hepatitis B infection, whereas pegylated interferon (Peg-IFN) induces a long-lasting response only in a subset of patients. We assessed the effect of sequential combination therapy with Peg-IFN-␣2a and entecavir in hepatitis B e antigen (HBeAg)-positive patients with prior long-term entecavir therapy and investigated the predictors of response to treatment. HBeAg-positive individuals who did not achieve HBeAg seroconversion during previous long-term entecavir therapy, receiving Peg-IFN-␣2a added to ongoing entecavir therapy (sequential combination [S-C] therapy; n ‫؍‬ 81) for 48 weeks or remaining on entecavir monotherapy (n ‫؍‬ 116), were retrospectively included. A matched pair was created at a 1:1 ratio from each treatment group. The primary endpoint was HBeAg seroconversion at week 48. Subgroup analysis of response prediction was conducted for 81 patients with S-C therapy. More patients in the S-C therapy group achieved HBeAg seroconversion than those in the entecavir group (44% versus 6%; P < 0.0001). An HBeAg level of <200 signal-to-cutoff ratio (S/CO) at baseline was a strong predictor for higher HBeAg seroconversion than that achieved when HBeAg was >200 S/CO (64.2% versus 17.9%; P < 0.0001). Hepatitis B surface antigen (HBsAg) levels at baseline and the decrease in HBsAg levels predicted HBsAg loss in the S-C therapy group. The combination of baseline HBeAg of <200 S/CO and HBsAg of <1,000 IU/ml and an HBsAg decline at week 12 of >0.5 log 10 IU/ml provided the highest rate of HBeAg seroconversion (92.31%) and HBsAg loss (83.3%) at week 48. Patients receiving sequential combination therapy have a higher rate of HBeAg seroconversion and are more likely to experience HBsAg clearance than do those continuing entecavir monotherapy. Sequential combination therapy can be guided by baseline HBsAg/HBeAg levels and on-treatment HBsAg dynamics. Hepatitis B virus (HBV) infection is endemic in Asia, the Pacific islands, Africa, Southern Europe, and Latin America, and chronic hepatitis B (CHB) is a global health threat. There are approximately 350 million chronic HBV surface antigen (HBsAg) carriers worldwide (1). Patients with CHB have an increased risk of developing cirrhosis, hepatic decompensation, and hepatocellular carcinoma (HCC), which results in about 1 million deaths per year (2). Antiviral treatment is effective in halting progression of CHB in many patients. Two classes of antiviral agents are available: nucleos(t)ide analogues (NUCs), such as entecavir (ETV), which inhibit the viral polymerase and interfere with viral replication, and interferon alpha (IFN-␣), including conventional and pegylated forms, which has antiviral and immunomodulatory effects (3). NUCs are effective in most patients but must be continued indefinitely in the patients that do not achieve hepatitis B e antigen (HBeAg) seroconversion. In contrast, a finite course of pegylated IFN-␣ (Peg-IFN-␣) can induce a long-lasting therapeutic response, but on...

Lysine crotonylation is a newly discovered protein post-translational modification and was reported to share transferases and deacylases with lysine acetylation. The acetyltransferase p300 was reported to also contain crotonyltransferase activity, and class I histone deacetylases were demonstrated to be the major histone decrotonylases. However, the decrotonylases for nonhistone proteins are unclear. Moreover, because of the lack of high-quality pan-antibodies, large-scale analysis of crotonylome still remains a challenge. In this work, we comprehensively studied lysine crotonylome on both histones and nonhistone proteins upon SAHA treatment and dramatically identified 10 163 lysine crotonylation sites in A549 cells. This is the first identification of tens of thousands of lysine crotonylation sites and also the largest lysine crotonylome data set up to now. Moreover, a parallel-reaction-monitoring-based experiment was performed for validation, which presented highly consistent results with the SILAC experiments. By intensive bioinformatic analysis, it was found that lysine crotonylation participates in a wide range of biological functions and processes. More importantly, it was revealed that both the crotonylation and acetylation levels of most core histones sites and a number of nonhistone proteins as well as some known substrates of class IIa and IIb HDACs were up-regulated after SAHA treatment. These results suggest that SAHA may have decrotonylation inhibitory activities on both histones and nonhistone proteins by inhibiting HDACs.

The c-Myc proto-oncogene is activated in more than half of all human cancers. However, the precise regulation of c-Myc protein stability is unknown. Here, we show that the lncRNA-MIF (c-Myc inhibitory factor), a c-Myc-induced long non-coding RNA, is a competing endogenous RNA for miR-586 and attenuates the inhibitory effect of miR-586 on Fbxw7, an E3 ligase for c-Myc, leading to increased Fbxw7 expression and subsequent c-Myc degradation. Our data reveal the existence of a feedback loop between c-Myc and lncRNA-MIF, through which c-Myc protein stability is finely controlled. Additionally, we show that the lncRNA-MIF inhibits aerobic glycolysis and tumorigenesis by suppressing c-Myc and miR-586.