A Novel Drug, CC-122, Inhibits Tumor Growth in Hepatocellular Carcinoma through Downregulation of an Oncogenic TCF-4 Isoform

Detection of Naturally occurring abortive transcripts by Base-Stacking Hybridization Assisted Ligation and PCR amplification

Abortive transcripts (ATs) refer to nascent 2-10 nucleotides (nt) RNAs released by RNA polymerases before synthesizing productive RNAs. The quantitative detection of ATs is important for studying transcription initiation and the biological function of ATs; however, no method is available for the qualitative and quantitative assessment of such ultra-short oligonucleotides (typically shorter than 11 nt) in vivo at present, even with the LNA probes, the detection limit can only reach 11 nt. Here, we demonstrated the base stacking hybridization assisted ligation (BSHAL) technique, combined with TaqMan-MGB qPCR, can detect 4-10 nt ATs with a specificity of nucleotide resolution and a sensitivity of approximately 10 pM. By this technique, we detected endogenous ATs in cell lines, mice plasmas, and mice liver tissues, respectively, and proved that naturally occurring ATs do exist. We found that the 8 nt ATs of HMSB and Gapdh could be used as reference ATs for data normalization in Homo and mouse respectively, and 8 nt ATs of Afp and Gpc3 were suitable for use as plasma biomarkers of Hepatocellular carcinoma in mouse, indicate ATs are promising biomarkers. This study offers opportunities to study ATs and other ultra-short oligonucleotides in biological samples.

Anti-tumor effect of avadomide in gemcitabine-resistant pancreatic ductal adenocarcinoma

PURPOSE

Although gemcitabine-based chemotherapy is most recommended for pancreatic ductal adenocarcinoma (PDAC), its effectiveness is limited because of drug resistance. Given thalidomide's anti-tumor effects in solid tumors, we investigated the effect of avadomide, a novel thalidomide analog, on PDAC and explored its anti-tumor mechanisms.

METHODS

PDAC cell lines, including gemcitabine-resistant (GR) clones derived from MiaPaCa2 cells, were used to evaluate the effects of avadomide. An annexin V assay, a cell cycle assay, and western blot analysis were performed to explain the mechanism of avadomide as an anti-tumor reagent. Moreover, we investigated the anti-tumor effect on tumor growth using a subcutaneous xenograft murine model.

RESULTS

Avadomide showed anti-tumor effects in human PDAC cell lines. The proportion of apoptotic cells and G0/G1 phase cells after avadomide treatment increased, especially in the GR PDAC clones. Western blot analysis also showed the induction of the apoptotic pathway by inhibiting the NF-κB process and G1 phase cell cycle arrest. The xenograft murine model revealed that the proportion of viable cells in the avadomide-treated group was lower than that in the untreated group.

CONCLUSION

Our findings suggest that avadomide could be a novel therapeutic option to overcome gemcitabine resistance in patients with PDAC.

miR-20a/TCF4 axis-mediated inhibition of hepatocytes proliferation impairs liver regeneration in mice PHx model by regulating CDC2 and CDC6

MicroRNAs have emerged as essential regulators in the biological process of liver regeneration by modulating the post‐transcriptional expression of the target genes. In the present study, we found miR‐20a expression is decreased remarkably in three rodent liver regeneration models using miRNA PCR array and Venn diagram analysis. Inhibition of miR‐20a expression enhanced hepatocytes proliferation in vivo and in vitro. In contrast, overexpression of miR‐20a reduces hepatocytes proliferation and subsequently impaired liver regeneration in the mouse PHx model. Moreover, we have identified TCF4 as a target gene of miR‐20a using the PCR Array and luciferase assay. Next, mice with TCF4 deficiency were used to establish the PHx model and subjected to the examination of liver regeneration capacity. We found TCF4‐deficient mice exhibited impaired liver regeneration compared with control. Given that TCF4 acts as a transcription factor, we sort to elucidate the downstream genes involved in liver regeneration. Promoter analysis and Chip assay confirmed that TCF4 enhances CDC2 and CDC6 expression through binding to the promoter region and leads to the proliferation and cell cycle progression in hepatocytes. In conclusion, this study provides evidence that the miR20a‐TCF4‐CDC2/6 axis plays an essential role during liver regeneration.

Population Pharmacokinetics of CC-122

Background

CC-122 is a cereblon-modulating agent that exerts direct cell-autonomous activity against malignant B cells and immunomodulatory effects. Herein, a population pharmacokinetic (popPK) model of CC-122 was developed and the influence of demographic and disease-related covariates on population pharmacokinetic parameters was assessed based on data from three clinical studies of CC-122 (dose range, 0.5–15 mg) in healthy subjects and cancer patients.

Methods

Nonlinear mixed effects modeling was employed in developing a population pharmacokinetic model of CC-122 based on 298 patients from 3 clinical studies.

Results

The PK of CC-122 was adequately described with a two-compartment model with first-order absorption and elimination. Tumor types were found to be significantly correlated with apparent clearance (CL/F) and apparent volume of distribution of the central compartment. Creatinine clearance was identified as a statistically significant covariate of CL/F. Sex and body weight were statistically but not clinically relevant on V2/F.

Conclusion

In conclusion, the two-compartment model built can be used to adequately describe the time course of the population pharmacokinetics of CC-122 and should serve as the basis for dose adjustment decision-making of CC-122.

Single-Dose Pharmacokinetics, Safety, and Tolerability of Avadomide (CC-122) in Subjects With Mild, Moderate, or Severe Renal Impairment

CC-122 (Avadomide) is a nonphthalimide analogue of thalidomide that has multiple pharmacological activities including immune modulation of several immune cell subsets, antigrowth activity, antiproliferative activity, and antiangiogenic activity. CC-122 as monotherapy and in combination with other agents is being evaluated for multiple indications including hematologic malignancies and advanced solid tumors. Given that renal clearance is one of the major routes of elimination for CC-122 and its clearance/exposure could be affected by renal impairment, a total of 50 subjects with various degrees of renal function were enrolled in an open-label, single-dose study to evaluate the impact of renal impairment on CC-122 pharmacokinetic disposition. The study showed that following administration of a single oral dose of 3 mg CC-122, renal impairment reduced both the apparent total plasma clearance and renal clearance of CC-122, but it had less impact on CC-122 absorption, as demonstrated by similar T_max and C_max among groups with various degrees of renal function. Compared with exposure in subjects with normal renal function, total plasma exposure to CC-122 increased by ∼20%, ∼50%, and ∼120% in subjects with mild, moderate, and severe renal insufficiency, respectively. Results from this study combined with modeling/simulation suggest that dose adjustments are necessary in patients with moderate or severe but not with mild renal impairment. Finally, a single dose of 3 mg CC-122 was safe and well tolerated by healthy subjects and subjects with mild, moderate, and severe renal impairment.