scholarly journals The role of delta like non-canonical Notch ligand 1 (DLK1) in cancer

2021 ◽  
Author(s):  
James Frederick Henry Pittaway ◽  
Constantinos Lipsos ◽  
Katia Mariniello ◽  
Leonardo Guasti
Keyword(s):  
High Frequency ◽  
Transmembrane Protein ◽  
Chromosome Band ◽  
Imprinted Genes ◽  
Potential Therapeutic Target ◽  
Notch Signalling Pathway ◽  
Notch Ligand ◽  
Worse Prognosis ◽  
Endocrine Tissues

Delta like non-canonical Notch ligand 1 (DLK1) is a cleavable single-pass transmembrane protein and a member of the Notch/Delta/Serrate family. It is paternally expressed and belongs to a group of imprinted genes located on chromosome band 14q32 in humans and 12qF1 in mice. DLK1 is expressed in many human tissues during embryonic development but in adults expression is low and is mostly restricted to (neuro)endocrine tissues and other immature stem/progenitor cells (notably hepatoblasts). However, DLK1 is expressed at a high frequency in many common malignancies (liver, breast, brain, pancreas, colon and lung). More recently, high levels of expression have been identified in endocrine related cancers such as ovarian and adrenocortical carcinoma. There is growing evidence that DLK1 expression in cancer is associated with worse prognosis and that DLK1 may be a marker of cancer stem cells. Although the exact mechanism through which DLK1 functions is not fully understood, it is known to maintain cells in an undifferentiated phenotype and has oncogenic properties. These effects are partly exacted through interaction with the Notch signalling pathway. In this review, we have detailed the functional role of DLK1 within physiology and malignancy and posit a mechanism for how it exacts its oncogenic effects. In describing the expression of DLK1 in cancer and in healthy tissue, we have highlighted the potential for its use both as a biomarker and as a potential therapeutic target.

Calculation-and-experimental estimation of the role of the frequency ratio in changing the endurance at two-frequency deformation modes

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 64-71 ◽  
Author(s):  
M. M. Gadenin
Keyword(s):  
High Frequency ◽  
Experimental Studies ◽  
Low Frequency ◽  
Reduction Factor ◽  
Single Frequency ◽  
Cyclic Loads ◽  
Small Ratio ◽  
Harmonic Components ◽  
Deformation Modes

The cycle configuration at two-frequency loading regimes depends on the number of parameters including the absolute values of the frequencies and amplitudes of the low-frequency and high-frequency loads added during this mode, the ratio of their frequencies and amplitudes, as well as the phase shift between these harmonic components, the latter having a significant effect only with a small ratio of frequencies. Presence of such two-frequency regimes or service loading conditions for parts of machines and structures schematized by them can significantly reduce their endurance. Using the results of experimental studies of changes in the endurance of a two-frequency loading of specimens of cyclically stable, cyclically softened and cyclically hardened steels under rigid conditions we have shown that decrease in the endurance under the aforementioned conditions depends on the ratio of frequencies and amplitudes of operation low-frequency low-cycle and high-frequency vibration stresses, and, moreover, the higher the level of the ratios of amplitudes and frequencies of those stacked harmonic processes of loading the greater the effect. It is shown that estimation of such a decrease in the endurance compared to a single frequency loading equal in the total stress (strains) amplitudes can be carried out using an exponential expression coupling those endurances through a parameter (reduction factor) containing the ratio of frequencies and amplitudes of operation cyclic loads and characteristic of the material. The reduction is illustrated by a set of calculation-experimental curves on the corresponding diagrams for each of the considered types of materials and compared with the experimental data.

T2 Gallbladder Cancer—Aggressive Therapy is Warranted

2016 ◽  
Vol 82 (6) ◽  
pp. 518-521 ◽  
Author(s):  
Mohd Raashid Sheikh ◽  
Houssam Osman ◽  
Susannah Cheek ◽  
Shenee Hunter ◽  
Dhiresh Rohan Jeyarajah
Keyword(s):  
Clinical Presentation ◽  
Radical Surgery ◽  
Radical Resection ◽  
Gall Bladder Cancer ◽  
Incidental Diagnosis ◽  
Radical Cholecystectomy ◽  
Node Positive ◽  
Operative Findings ◽  
Worse Prognosis

Treatment of gall bladder cancer (GBC) has traditionally been viewed with pessimism and lymph node positivity has been associated with worse prognosis. The aim of this study is to analyze the role of radical cholecystectomy in T2 tumors. All patients who underwent surgery for GBC between September 2005 and June 2014 were identified retrospectively. Data collected included clinical presentation, operative findings, and histopathological data. Twenty-five patients had incidental GBC diagnosis after cholecystectomy. Ten patients were T2 on initial cholecystectomy pathology and all underwent radical resection. Two patients were N1 on initial cholecystectomy pathology. Four were upstaged to N1 and two patients were upstaged to T3 after further surgery. Overall, 60 per cent patients with T2 disease had node positivity and 60 per cent were upstaged by further surgery. Eleven patients were diagnosed on imaging. Four of these patients were unresectable and six were either stage T3 or higher or node positive. Sixty per cent of T2 GBC was node positive and 60 per cent were upstaged with radical cholecystectomy. This finding supports the call for radical resection in patients with incidental diagnosis of T2 tumor on cholecystectomy. This study also emphasizes the role of radical surgery in accurate T staging.

scholarly journals Sialic Acid—Modified Nanoparticles—New Approaches in the Glioma Management—Perspective Review

2021 ◽  
Vol 22 (14) ◽  
pp. 7494
Author(s):  
Przemyslaw Wielgat ◽  
Katarzyna Niemirowicz-Laskowska ◽  
Agnieszka Z. Wilczewska ◽  
Halina Car
Keyword(s):  
Sialic Acid ◽  
Clinical Observation ◽  
Malignant Cell ◽  
Cellular Heterogeneity ◽  
Molecular Processes ◽  
Management Perspective ◽  
Therapeutic Tools ◽  
And Function ◽  
Worse Prognosis

The cell surface is covered by a dense and complex network of glycans attached to the membrane proteins and lipids. In gliomas, the aberrant sialylation, as the final stage of glycosylation, is an important regulatory mechanism of malignant cell behavior and correlates with worse prognosis. Better understanding of the role of sialylation in cellular and molecular processes opens a new way in the development of therapeutic tools for human brain tumors. According to the recent clinical observation, the cellular heterogeneity, activity of brain cancer stem cells (BCSCs), immune evasion, and function of the blood–brain barrier (BBB) are attractive targets for new therapeutic strategies. In this review, we summarize the importance of sialic acid-modified nanoparticles in brain tumor progression.

scholarly journals Overexpressed pseudogene MT1L associated with tumor immune infiltrates and indicates a worse prognosis in BLCA

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yanpeng Ding ◽  
Nuomin Liu ◽  
Mengge Chen ◽  
Yulian Xu ◽  
Sha Fang ◽  
...  
Keyword(s):  
Immune Cells ◽  
Biological Function ◽  
Prognostic Biomarker ◽  
Poor Survival ◽  
Common Cancer ◽  
Kaplan Meier ◽  
Cox Analysis ◽  
Kaplan Meier Plotter ◽  
Worse Prognosis

Abstract Background BLCA is a common cancer worldwide, and it is both aggressive and fatal. Immunotherapy (ICT) has achieved an excellent curative effect in BLCA; however, only some BLCA patients can benefit from ICT. MT1L is a pseudogene, and a previous study suggested that MT1L can be used as an indicator of prognosis in colorectal cancer. However, the role of MT1L in BLCA has not yet been determined. Methods Data were collected from TCGA, and logistic regression, Kaplan-Meier plotter, and multivariate Cox analysis were performed to demonstrate the correlation between the pseudogene MT1L and the prognosis of BLCA. To identify the association of MT1L with tumor-infiltrating immune cells, TIMER and TISIDB were utilized. Additionally, GSEA was performed to elucidate the potential biological function. Results The expression of MT1L was decreased in BLCA. Additionally, MT1L was positively correlated with immune cells, such as Tregs (ρ = 0.708) and MDSCs (ρ = 0.664). We also confirmed that MT1L is related to typical markers of immune cells, such as PD-1 and CTLA-4. In addition, a high MT1L expression level was associated with the advanced T and N and high grade in BLCA. Increased expression of MT1L was significantly associated with shorter OS times of BLCA patients (p < 0.05). Multivariate Cox analysis revealed that MT1L expression could be an independent prognostic factor in BLCA. Conclusion Collectively, our findings demonstrated that the pseudogene MT1L regulates the immune microenvironment, correlates with poor survival, and is an independent prognostic biomarker in BLCA.

scholarly journals YAP inhibits autophagy and promotes progression of colorectal cancer via upregulating Bcl-2 expression

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Lan Jin ◽  
Yunhe Chen ◽  
Dan Cheng ◽  
Zhikai He ◽  
Xinyi Shi ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Death ◽  
Transcriptional Coactivator ◽  
Inhibitory Protein ◽  
Potential Therapeutic Target ◽  
Related Cell ◽  
Autophagy Inhibition

AbstractColorectal cancer (CRC) is one of the most aggressive and lethal cancers. The role of autophagy in the pathobiology of CRC is intricate, with opposing functions manifested in different cellular contexts. The Yes-associated protein (YAP), a transcriptional coactivator inactivated by the Hippo tumor-suppressor pathway, functions as an oncoprotein in a variety of cancers. In this study, we found that YAP could negatively regulate autophagy in CRC cells, and consequently, promote tumor progression of CRC in vitro and in vivo. Mechanistically, YAP interacts with TEAD forming a complex to upregulate the transcription of the apoptosis-inhibitory protein Bcl-2, which may subsequently facilitate cell survival by suppressing autophagy-related cell death; silencing Bcl-2 expression could alleviate YAP-induced autophagy inhibition without affecting YAP expression. Collectively, our data provide evidence for YAP/Bcl-2 as a potential therapeutic target for drug exploration against CRC.

scholarly journals The role of Notch ligand, Delta-like ligand 4 (DLL4), in cancer angiogenesis—implications for therapy

2021 ◽  
Author(s):  
Marlena Brzozowa-Zasada
Keyword(s):  
Cancer Therapy ◽  
Notch Signalling ◽  
Signalling Pathway ◽  
Gamma Secretase ◽  
Tumour Angiogenesis ◽  
Notch Signalling Pathway ◽  
Expression Levels ◽  
Blocking Agents ◽  
Anti Cancer

Summary Background It is generally accepted that angiogenesis is a complex and tightly regulated process characterized by the growth of blood vessels from existing vasculature. Activation of the Notch signalling pathway affects multiple aspects of vascular development. One of the components of the Notch signalling pathway, Delta-like ligand 4 (DLL4), has recently appeared as a critical regulator of tumour angiogenesis and thus as a promising therapeutic target. Methods This review article includes available data from peer-reviewed publications associated with the role of DLL4 in cancer angiogenesis. Searches were performed in PubMed, EMBASE, Google Scholar and Web of Science using the terms “tumour angiogenesis”, “DLL4”, “Notch signalling” and “anti-cancer therapy”. Results The survival curves of cancer patients revealed that the patients with high DLL4 expression levels had significantly shorter survival times than the patients with low DLL4 expression. Moreover, a positive correlation was also identified between DLL4 and VEGF receptorsʼ expression levels. It seems that inhibition of DLL4 may exert potent growth inhibitory effects on some tumours resistant to anti-VEGF therapies. A great number of blocking agents of DLL4/Notch signalling including anti-DLL4 antibodies, DNA vaccination, Notch antibodies and gamma-secretase inhibitors have been studied in preclinical tumour models. Conclusion DLL4 seems to be a promising target in anti-cancer therapy. Nevertheless, the careful evaluation of adverse effects on normal physiological processes in relation to therapeutic doses of anti-DLL4 drugs will be significant for advancement of DLL4 blocking agents in clinical oncology.

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