"Five-point eight-line" anatomic flap design for precise hemitongue reconstruction.

BACKGROUND: Reconstruction of hemiglossectomy defects requires careful flap design to avoid adverse functional and aesthetic outcomes. METHODS: Hemitongue specimens were obtained from minipigs to study the three-dimensional anatomy and to define anatomic landmarks for precise measurements of flap requirement. The concept developed in animal models was then applied to hemiglossectomy reconstruction in clinical practice. Sixty-one patients were randomly enrolled into the following two groups: a "five-point eight-line segment" (FIPELS) flap design group (28 patients) and a conventional group (33 patients). Functional and aesthetic outcomes were compared between the two groups. RESULTS: All flaps designed with the FIPELS technique matched the hemiglossectomy defects without the need for flap trimming, thus reducing the operating time (P = .03). Swallowing functions, speech intelligibility, and aesthetic outcomes were superior in the FIPELS group than that in the conventional group (P < .05). CONCLUSIONS: The FIPELS flap design for hemiglossectomy reconstruction yields improved functional and aesthetic outcomes compared to a conventional flap design.

The Use of a Honeycomb Technique Combined with Ultrasonic Aspirators and Indocyanine Green Fluorescence Angiography for a Superthin Anterolateral Thigh Flap: A Pilot Study.

BACKGROUND: Harvesting an optimally thinned anterolateral thigh flaps is a challenge in overweight individuals and in the Western population. The authors describe a novel honeycomb technique to achieve a superthin anterolateral thigh flap in overweight patients. METHODS: Forty patients with a body mass index greater than 25 kg/m(2) who required a thinned anterolateral thigh flap for reconstruction were assigned randomly to a honeycomb technique group or a microdissection technique group. The honeycomb technique group underwent flap thinning with the Cavitron Ultrasonic Surgical Aspirator, and flap thinning was performed with a conventional microdissection technique in the microdissection technique group. Perfusion of all flaps was measured by indocyanine green fluorescence angiography before and after thinning. Hypoperfusion was defined as 30 percent. RESULTS: The mean body mass index was 28.6 ± 2.0 kg/m(2) and 27.3 ± 1.9 kg/m(2) in the honeycomb group and the microdissection group, respectively. Flap size, perforator, type of dissection, and initial perfusion were comparable between the two groups. However, significantly more patients (nine of 21) experienced final hypoperfusion in the microdissection group than in the honeycomb group (two of 19) (p = 0.034). In addition, blood loss and final flap thickness were significantly lower in the honeycomb group (p < 0.05), and the duration of thinning was comparable between the two groups. No flap necrosis was found in either group. CONCLUSION: The honeycomb technique in combination with the Cavitron Ultrasonic Surgical Aspirator and indocyanine green angiography was able to remove adipose tissue but protect the integrity of the subcutaneous vascular plexus to reduce potential risk of jeopardizing flap perfusion while obtaining a superthin anterolateral thigh flap in an overweight population. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Chromatin accessibility contributes to simultaneous mutations of cancer genes.

Somatic mutations of many cancer genes tend to co-occur (termed co-mutations) in certain patterns during tumor initiation and progression. However, the genetic and epigenetic mechanisms that contribute to the co-mutations of these cancer genes have yet to be explored. Here, we systematically investigated the association between the somatic co-mutations of cancer genes and high-order chromatin conformation. Significantly, somatic point co-mutations in protein-coding genes were closely associated with high-order spatial chromatin folding. We propose that these regions be termed Spatial Co-mutation Hotspots (SCHs) and report their occurrence in different cancer types. The conserved mutational signatures and DNA sequences flanking these point co-mutations, as well as CTCF-binding sites, are also enriched within the SCH regions. The genetic alterations that are harboured in the same SCHs tend to disrupt cancer driver genes involved in multiple signalling pathways. The present work demonstrates that high-order spatial chromatin organisation may contribute to the somatic co-mutations of certain cancer genes during tumor development.

Targeting endogenous DLK1 exerts antitumor effect on hepatocellular carcinoma through initiating cell differentiation.

Cancer stem cells (CSCs) are responsible for tumor initiation and progression. We previously showed that Delta-like homolog 1 (DLK1) may be a therapeutic target against the CSCs of human hepatocellular carcinoma (HCC). However, the therapeutic efficacy and underlying mechanism remain unclear. Here we demonstrated that knockdown of DLK1 using a tet-inducible short hairpin RNA (shRNA) system significantly inhibited proliferation, spheroid formation and in vivo xenograft tumor growth of human HCC cells. Furthermore, in an orthotopic xenograft mouse model, adenovirus-mediated DLK1 knockdown could significantly reduce tumor size, as shown by in vivo imaging approach. Subsequently, an adenoviral vector harboring mouse Dlk1 shRNA was applied. The results showed that Dlk1 knockdown also could inhibit tumor progression in a diethylnitrosamine (DEN) induced mouse HCC model. At cellular mechanism, DLK1 knockdown delayed the cell cycle G1-S transition, along with the decreased expression of cyclin E1 and D1. Significantly, DLK1 knockdown resulted in the decrease of molecular markers such as AFP and EpCAM for hepatic progenitor cells, but the increase of KRT18 and KRT19 for the differentiated hepatocytes. The collective data indicated that targeting endogenous DLK1 may exert antitumor effect on HCCs possibly through initiating cell differentiation.

Epigenetic silencing of JMJD5 promotes the proliferation of hepatocellular carcinoma cells by down-regulating the transcription of CDKN1A 686.

Proteins that contain jumonji C (JmjC) domains have recently been identified as major contributors to various malignant human cancers through epigenetic remodeling. However, the roles of these family members in the pathogenesis of hepatocellular carcinoma (HCC) are obscure. By mining public databases, we found that the HCC patients with lower JmjC domain-containing protein 5 (JMJD5) expression exhibited shorter survival time. We then confirmed that JMJD5 expression was indeed decreased in HCC specimens, which was caused by the altered epigenetic histone modifications, the decreased H3K9ac, H3K27ac and H3K4me2/3 together with the increased trimethylation of H3K27 and H3K9 on the JMJD5 promoter. Functional experiments revealed that JMJD5 knockdown promoted HCC cell proliferation and in vivo tumorigenicity by accelerating the G1/S transition of the cell cycle; in contrast, ectopic JMJD5 expression had the opposite effects. At molecular mechanism, we found that, in HCC cell lines including TP53-null Hep3B, JMJD5 knockdown led to the down-regulation of CDKN1A and ectopic expression of JMJD5 not only increased but also rescued CDKN1A transcription. Moreover, CDKN1A knockdown could abrogate the effect of JMJD5 knockdown or overexpression on cell proliferation, suggesting that JMJD5 inhibits HCC cell proliferation mainly by activating CDKN1A expression. We further revealed that JMJD5 directly enhances CDKN1A transcription by binding to CDKN1A's promoter independent of H3K36me2 demethylase activity. In short, we first prove that JMJD5 is a tumor suppressor gene in HCC pathogenesis, and the epigenetic silencing of JMJD5 promotes HCC cell proliferation by directly down-regulating CDKN1A transcription.

Deficiency of IRTKS as an adaptor of insulin receptor leads to insulin resistance.

IRTKS encodes a member of the IRSp53/MIM homology domain family, which has been shown to play an important role in the formation of plasma membrane protrusions. Although the phosphorylation of IRTKS occurs in response to insulin stimulation, the role of this protein in insulin signaling remains unknown. Here we show that IRTKS-deficient mice exhibit insulin resistance, including hyperglycemia, hyperinsulinemia, glucose intolerance, decreased insulin sensitivity, and increased hepatic glucose production. The administration of ectopic IRTKS can ameliorate the insulin resistance of IRTKS-deficient and diabetic mice. In parallel, the expression level of IRTKS was significantly decreased in diabetic mouse model. Furthermore, DNA hypermethylation of the IRTKS promoter was also observed in these subjects. We also show that IRTKS, as an adaptor of the insulin receptor (IR), modulates IR-IRS1-PI3K-AKT signaling via regulating the phosphorylation of IR. These findings add new insights into our understanding of insulin signaling and resistance.

Insulin receptor tyrosine kinase substrate activates EGFR/ERK signalling pathway and promotes cell proliferation of hepatocellular carcinoma.

Insulin receptor tyrosine kinase substrate (IRTKS) is closely associated with actin remodelling and membrane protrusion, but its role in the pathogenesis of malignant tumours, including hepatocellular carcinoma (HCC), is still unknown. In this study, we showed that IRTKS was frequently upregulated in HCC samples, and its expression level was significantly associated with tumour size. Enforced expression of IRTKS in human HCC cell lines significantly promoted their proliferation and colony formation in vitro, and their capacity to develop tumour xenografts in vivo, whereas knockdown of IRTKS resulted in the opposite effects. Furthermore, the bromodeoxyuridine (BrdU) incorporation analyses and propidium iodide staining indicated that IRTKS can promote the entry into S phase of cell cycle progression. Significantly, IRTKS can interact with epidermal growth factor receptor (EGFR), results in the phosphorylation of extracellular signal-regulated kinase (ERK). By contrast, inhibition of ERK activation can attenuate the effects of IRTKS overexpression on cellular proliferation. Taken together, these data demonstrate that IRTKS promotes the proliferation of HCC cells by enhancing EGFR-ERK signalling pathway.