Epigenetic signature associated with thyroid cancer progression and metastasis

DNMT1/miR-152-3p/SOS1 signaling axis promotes self-renewal and tumor growth of cancer stem-like cells derived from non-small cell lung cancer

BACKGROUND

CSLCs(Cancer stem cell-like cells), which are central to tumorigenesis, are intrinsically influenced by epigenetic modifications. This study aimed to elucidate the underlying mechanism involving the DNMT1/miR-152-3p/SOS1 axis in regulating the self-renewal and tumor growth of LCSLCs (lung cancer stem-like cells).

MATERIALS AND METHODS

Target genes of miR-152-3p were predicted using TargetScan Human 8.0. Self-renewal and tumor growth of LCSLC were compared in suspension-cultured non-small cell lung cancer (NSCLC) cell lines H460 and A549 cell-derived globe cells. Functional effects of the DNMT1/miR-152-3p/SOS1 axis were assessed through gain-of-function experiments in vitro and in vivo. Additionally, luciferase reporter assays were employed to analyze the interaction among DNMT1, miR-152-3p, and SOS1.

RESULTS

Our findings highlight a negative interaction between DNMT1 and miR-152-3p, resulting in reduced miR-152-3p level. This, in turn, leads to the alleviation of the inhibitory effect of miR-152-3p on the target gene SOS1, ultimately activating SOS1 and playing an essential role in self-renewal and tumor growth of LCSLC. However, the alteration of SOS1 does not affect DNMT1/miR-152-3p regulation. Therefore, it is reasonable to infer that the DNMT1/miR-152-3p negative feedback loop critically sustains self-renewal and tumor growth of LCSLC through SOS1.

CONCLUSIONS

This study reveals a novel mechanism underpinning self-renewal and tumor growth of CSLC (cancer stem cell) in NSCLC and identifies potential therapeutic targets for NSCLC treatment.

N6-methyladenosine-modified VGLL1 promotes ovarian cancer metastasis through high-mobility group AT-hook 1/Wnt/β-catenin signaling

The main causes of death in patients with ovarian cancer (OC) are invasive lesions and the spread of metastasis. The present study aimed to explore the mechanisms that might promote OC metastasis. Here, we identified that VGLL1 expression was remarkably increased in metastatic OC samples. The role of VGLL1 in OC metastasis and tumor growth was examined by cell function assays and mouse models. Mechanistically level, METTL3-mediated N6-methyladenosine (m6A) modification contributed to VGLL1 upregulation in an IGF2BP2 recognition-dependent manner. Furthermore, VGLL1 directly interacts with TEAD4 and co-transcriptionally activates HMGA1. HMGA1 further activates Wnt/β-catenin signaling to enhance OC metastasis by promoting the epithelial-mesenchyme transition traits. Rescue assays indicated that the upregulation of HMGA1 was essential for VGLL1-induced metastasis. Collectively, these findings showed that the m6A-induced VGLL1/HMGA1/β-catenin axis might play a vital role in OC metastasis and tumor growth. VGLL1 might serve as a prognostic marker and therapeutic target against the metastasis of OC.

Effects of low-dose dexamethasone on inflammatory factors in drainage fluid and wound healing after thyroid surgery during perioperative period

This study explored the effect of perioperative use of low-dose dexamethasone on inflammatory factors in drainage fluid and wound healing after thyroid surgery. In the prospective, double-blinded, randomised controlled study, adults who underwent elective thyroidectomy received 0.1 mg/kg of intravenous dexamethasone or a matching volume of placebo (saline) after induction of general anaesthesia. The primary outcome was IL6 and IL10 concentration in drainage at 24 hours postoperative. The secondary endpoint was the SBSES (modified Stony Brook Scar Evaluation Scale) total score at 1 week postoperative. From 8 July to 17 December 2020, 64 patients (mean [SD] age, 40.42 [9.52]; 13 males [20.31%]) were recruited, received operation, and completed the 1-month follow-up. Inflammatory factors in drainage did not differ between the two groups but only had significant differences at different timepoint. The dexamethasone group patients had a higher SBSES total score at 1 week after the treatment but, without statistical significance (dexamethasone vs placebo: 3.13 ± 1.24 vs 2.97 ± 0.93, P = .571). The dexamethasone group patients had a higher SBSES total score (dexamethasone vs placebo: 3.103 ± 1.148 vs 2.868 ± 0.827, P = .011) and colour score (dexamethasone vs placebo: 0.603 ± 0.493 vs 0.412 ± 0.496, P = .026) at 1-week follow-up than the placebo group patients. Preoperative single small-dose intravenous dexamethasone did not show to improve wound healing quality nor reduce incision inflammation but may release pain, and reduce tissue angiogenesis, and thus the scar redness.

Influence of Dehydroxymethylepoxyquinomicin on Radiosensitivity of Thyroid Carcinoma TPC-1 Cells

Objective. To investigate the influence of dehydroxymethylepoxyquinomicin (DHMEQ), an NF-κB inhibitor, on radiosensitivity of thyroid carcinoma (TC) TPC-1 cells. Methods. The isolation of CDl33 positive cells (CD133+ TPC-1) and negative cells (CD133- TPC-1) from TPC-1 cells used immunomagnetic bead sorting. After verification of the toxicity of DHMEQ to cells by MTT and cell cloning assays, the cells were divided into four groups, of which three groups were intervened by DHMEQ, 131I radiation, and DHMEQ +131I radiation, respectively, while the fourth group was used as a control without treatment. Alterations in cell growth, apoptosis, and cell cycle were observed. Results. DHMEQ had certain toxic effects on TPC-1 cells, with an IC50 of 38.57 μg/mL ( $P<0.05$ ). DHMEQ inhibited CD133+ and CD133- TPC-1 proliferation and their clonogenesis after irradiation. DHMEQ + radiation contributed to a growth inhibition rate and an apoptosis rate higher than either or them alone ( $P<0.05$ ), with a more significant effect on CD133- TPC-1 than CD133+ TPC-1 under the same treatment conditions ( $P<0.05$ ). Conclusion. DHEMQ can increase the radiosensitivity of TC cells to 131I, inhibit tumor cell growth, and promote apoptosis. However, its effect is less significant on CD133+ TPC-1 compared with CD133- TPC-1, which may be related to the stem cell-like properties of CD133+ cells. In the future, the application of DHMEQ in TC 131I radiotherapy will effectively improve the clinical effect of patients.