Deep analysis of N-cadherin/ADH-1 interaction: a computational survey

Regulation of tumor metastasis and CD8+ T cells infiltration by circRNF216/miR-576-5p/ZC3H12C axis in colorectal cancer

BACKGROUND

The tumor immune microenvironment (TIME) is an important regulator of tumor progression, growth and metastasis. In addition, tumor metastasis is one of the principal obstacles to the treatment of colorectal cancer (CRC). Circular RNAs (circRNAs) have been recognized as important regulators in the development of malignancies. However, their specific roles and mechanisms in both CRC metastasis and TIME have not been thoroughly investigated.

METHODS

High-throughput next-generation sequencing technology and real-time fluorescence quantitative PCR technology were performed to identify differential circRNAs in CRC. Functional assays including transwell assay, wound healing assay, and metastasis models were conducted to assess the effect of circRNF216 on CRC metastasis. In addition, luciferase reporter, western blot, RNA immunoprecipitation (RIP), and fluorescent in situ hybridization (FISH) were performed to explore the underlying mechanism of circRNF216. The level of immune infiltration was assessed by bioinformatics analysis and flow cytometry in CRC model. Furthermore, rescue and mutation experiments were used for verification.

RESULTS

circRNF216 was identified as a putative tumor suppressor that is downregulated in CRC tissues and cells. Overexpression of circRNF216 inhibits metastasis in vitro and vivo. Mechanistically, circRNF216 acts as a competitive endogenous RNA (ceRNA) for miR-576-5p, alleviating miR-576-5p repression on its target ZC3H12C, which in turn downregulated N-cadherin. Additionally, circRNF216 could enhance the infiltration level of CD8+ T cells by upregulating ZC3H12C, ultimately inhibiting the development of CRC, which suggests that circRNF216 is a potential biomarker for the treatment of CRC.

CONCLUSIONS

Here, we provide novel mechanistic insight revealing how circRNF216 functioned in CRC metastasis and TIME via the circRNF216/miR-576-5p/ZC3H12C pathway. Therefore, circRNF216 holds promise as a potential therapeutic target and novel diagnostic marker for CRC.

[18F]AlF-NOTA-ADH-1: A new PET molecular radiotracer for imaging of N-cadherin-positive tumors

Background

The cell adhesion molecule (CAM) N-cadherin has become an important target for tumor therapy. The N-cadherin antagonist, ADH-1, exerts significant antitumor activity against N-cadherin-expressing cancers.

Methods

In this study, [¹⁸F]AlF-NOTA-ADH-1 was radiosynthesized. An in vitro cell binding test was performed, and the biodistribution and micro-PET imaging of the probe targeting N-cadherin were also studied in vivo.

Results

Radiolabeling of ADH-1 with [¹⁸F]AlF achieved a yield of up to 30% (not decay-corrected) with a radiochemical purity of >97%. The cell uptake study showed that Cy3-ADH-1 binds to SW480 cells but weakly binds to BXPC3 cells in the same concentration range. The biodistribution results demonstrated that [¹⁸F]AlF-NOTA-ADH-1 had a good tumor/muscle ratio (8.70±2.68) in patient-derived xenograft (PDX) tumor xenografts but a lower tumor/muscle ratio (1.91±0.69) in SW480 tumor xenografts and lowest tumor/muscle ratio (0.96±0.32) in BXPC3 tumor xenografts at 1 h post-injection (p.i.) These findings were in accordance with the immunohistochemistry results. The micro PET imaging results revealed good [18F]AlF-NOTA-ADH-1 tumor uptake in pancreatic cancer PDX xenografts with strong positive N-calcium expression, while lower tumor uptake in SW480 xenografts with positive expression of N-cadherin, and significantly lower tumor uptake in BXPC3 xenografts with low expression of N-cadherin, which was consistent with the biodistribution and immunohistochemistry results. The N-cadherin-specific binding of [18F]AlF-NOTA-ADH-1 was further verified by a blocking experiment involving coinjection of a non radiolabeled ADH-1 peptide, resulting in a significant reduction in tumor uptake in PDX xenografts and SW480 tumor.

Conclusion

[¹⁸F]AlF-NOTA-ADH-1 was successfully radiosynthesized, and Cy3-ADH-1 showed favorable N-cadherin-specific targeting ability by in vitro data. The biodistribution and microPET imaging of the probe further showed that [18F]AlF-NOTA-ADH-1 could discern different expressions of N-cadherin in tumors. Collectively, the findings demonstrated the potential of [¹⁸F]AlF-NOTA-ADH-1 as a PET imaging probe for non-invasive evaluation of the N-cadherin expression in tumors.

Therapeutic targeting of anoikis resistance in cutaneous melanoma metastasis

The acquisition of resistance to anoikis, the cell death induced by loss of adhesion to the extracellular matrix, is an absolute requirement for the survival of disseminating and circulating tumour cells (CTCs), and for the seeding of metastatic lesions. In melanoma, a range of intracellular signalling cascades have been identified as potential drivers of anoikis resistance, however a full understanding of the process is yet to be attained. Mechanisms of anoikis resistance pose an attractive target for the therapeutic treatment of disseminating and circulating melanoma cells. This review explores the range of small molecule, peptide and antibody inhibitors targeting molecules involved in anoikis resistance in melanoma, and may be repurposed to prevent metastatic melanoma prior to its initiation, potentially improving the prognosis for patients.

Development and application of an agent-based model for the simulation of the extravasation process of circulating tumor cells

The primary cause for cancer-related death is metastasis, and although this phenomenon is the hallmark of cancer, it remains poorly understood. Since studies on the underlying mechanisms are still demanding by experimental means prognostic tools based on computer models can be of great value, not only for elucidating metastasis formation but also for assessing the prospective benefits as well as risks of a therapy for patients with advanced cancer. Here, we present an agent-based model (ABM), describing the complete process of platelet-assisted extravasation of circulating tumor cells (CTCs) from the chemoattraction of blood platelets by the CTCs up to the embedding of the CTCs in the epithelial tissue by computational means. From the simulation results, we conclude that the ABM produces results in consistency with experimental observations, which opens new perspectives for the development of computer models for predicting the efficacity of drug-based tumor therapies and assisting precision medicine approaches.

Development of 99mTc-Hynic-Adh-1 Molecular Probe Specifically Targeting N-Cadherin and Its Preliminary Experimental Study in Monitoring Drug Resistance of Non-Small-Cell Lung Cancer

BACKGROUND

N-cadherin is considered a characteristic protein of EMT and has been found to be closely related to tumor resistance. In this study, a novel molecular imaging probe, ^99mTc-HYNIC-ADH-1, was developed, and its diagnostic value in monitoring drug resistance in NSCLC was preliminarily investigated.

METHODS

ADH-1 was labeled indirectly with ^99mTc. Radiochemical purity and stability, partition coefficients and pharmacokinetics were evaluated. Additionally, the fluorescent probe of ADH-1 was synthesized to study tumor uptake in cells level and in vivo. Biodistribution analysis and small animal SPECT/CT were performed in PC9GR and PC9 tumor-bearing mice.

RESULTS

^99mTc-HYNIC-ADH-1 was highly stable (radiochemical purity ≥ 98% in PBS and serum after 24 h). A cell binding study and fluorescence imaging showed that the uptake was significantly higher in PC9GR cells (gefitinib-resistant) than in PC9 cells (nonresistant) (p < 0.05). Biodistribution analysis showed rapid blood clearance and significant uptake in the kidney and resistant tumor. Small animal SPECT/CT studies showed that uptake in PC9GR tumors (T/NT = 7.73 ± 0.54) was significantly higher than that in PC9 tumors (T/NT = 3.66 ± 0.78) at 1 h (p = 0.002).

CONCLUSIONS

The ^99mTc-HYNIC-ADH-1 molecular probe has a short synthesis time, high labeling rate, high radiochemical purity and good stability, does not require purification, is characterized by rapid blood clearance and is mainly excreted through the urinary system. ^99mTc-HYNIC-ADH-1 is considered a promising probe for monitoring drug resistance in NSCLC.

Telmisartan anti‐cancer activities mechanism through targeting N‐cadherin by mimicking ADH‐1 function

This study aimed to investigate if Telmisartan as a novel N‐cadherin antagonist, can overcome cell migration of cancer cells. We investigated the mechanism and influence of Docetaxel and Telmisartan (as an analogous to ADH‐1, which is a well‐known N‐cadherin antagonist) on cancer cells. The effect of ADH‐1 and Telmisartan on cell attachment in PC3, DU145, MDA‐MB‐468 cell lines using recombinant human N‐cadherin was studied. Cell viability assay was performed to examine the anti‐proliferative effects of Telmisartan, ADH‐1 and Docetaxel. Migration was examined via wound healing assay, and apoptosis was determined by flow cytometry. The expression of AKT‐1 as a downstream gene of N‐cadherin signalling pathway was assayed by real‐time PCR. Treatment of PC3, MDA‐MB‐468 and DU145 cells with Telmisartan (0.1 µM) and ADH‐1 (40 µM) resulted in 50%, 58% and approximately 20% reduction in cell attachment to N‐cadherin coated plate respectively. It shows reduction of cell attachment in PC3 and MDA‐MB‐468 cell lines appeared to be more sensitive than that of DU145 cells to the Telmisartan and ADH‐1 treatments. Telmisartan (0.1 µM) and Docetaxel (0.01 nM) significantly reduced cell migration in PC3 and MDA‐MB‐468 cell lines compared with the control group. Using Real‐time PCR, we found that Telmisartan, Docetaxel and ADH‐1 had significant influence on the AKT‐1 mRNA level. The results of the current study for the first time suggest that, Telmisartan, exerts anti‐proliferation and anti‐migration effects by targeting antagonistically N‐cadherin. Also, these data suggest that Telmisartan as a less expensive alternative to ADH‐1 could potentiate Docetaxel anticancer effects.

A systems pharmacology approach to identify the autophagy-inducing effects of Traditional Persian medicinal plants

Aging is correlated with several complex diseases, including type 2 diabetes, neurodegeneration diseases, and cancer. Identifying the nature of this correlation and treatment of age-related diseases has been a major subject of both modern and traditional medicine. Traditional Persian Medicine (TPM) embodies many prescriptions for the treatment of ARDs. Given that autophagy plays a critical role in antiaging processes, the present study aimed to examine whether the documented effect of plants used in TPM might be relevant to the induction of autophagy? To this end, the TPM-based medicinal herbs used in the treatment of the ARDs were identified from modern and traditional references. The known phytochemicals of these plants were then examined against literature for evidence of having autophagy inducing effects. As a result, several plants were identified to have multiple active ingredients, which indeed regulate the autophagy or its upstream pathways. In addition, gene set enrichment analysis of the identified targets confirmed the collective contribution of the identified targets in autophagy regulating processes. Also, the protein-protein interaction (PPI) network of the targets was reconstructed. Network centrality analysis of the PPI network identified mTOR as the key network hub. Given the well-documented role of mTOR in inhibiting autophagy, our results hence support the hypothesis that the antiaging mechanism of TPM-based medicines might involve autophagy induction. Chemoinformatics study of the phytochemicals using docking and molecular dynamics simulation identified, among other compounds, the cyclo-trijuglone of Juglans regia L. as a potential ATP-competitive inhibitor of mTOR. Our results hence, provide a basis for the study of TPM-based prescriptions using modern tools in the quest for developing synergistic therapies for ARDs.

Decreasing the immunogenicity of Erwinia chrysanthemi asparaginase via protein engineering: computational approach

Immunogenicity of therapeutic proteins is one of the main challenges in disease treatment. L-Asparaginase is an important enzyme in cancer treatment which sometimes leads to undesirable side effects such as immunogenic or allergic responses. Here, to decrease Erwinase (Erwinia chrysanthemiL-Asparaginase) immunogenicity, which is the main drawback of the enzyme, firstly conformational B cell epitopes of Erwinase were predicted from three-dimensional structure by three different computational methods. A few residues were defined as candidates for reducing immunogenicity of the protein by point mutation. In addition to immunogenicity and hydrophobicity, stability and binding energy of mutants were also analyzed computationally. In order to evaluate the stability of the best mutant, molecular dynamics simulation was performed. Among mutants, H240A and Q239A presented significant reduction in immunogenicity. In contrast, the immunogenicity scores of D235A slightly decreased according to two servers. Binding affinity of substrate to the active site reduced significantly in K265A and E268A. The final results of molecular dynamics simulation indicated that H240A mutation has not changed the stability, flexibility, and the total structure of desired protein. Overall, point mutation can be used for reducing immunogenicity of therapeutic proteins, in this context, in silico approaches can be used to screen suitable mutants.