Integrin β3 Inhibition Enhances the Antitumor Activity of ALK Inhibitor in ALK-Rearranged NSCLC

The role of thrombomodulin in modulating ITGB3 expression and its implications for triple-negative breast cancer progression

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer (BC) compared to other BC subtypes in clinical settings. Currently, there are no effective therapeutic strategies for TNBC treatment. Therefore, there is an urgent need to identify suitable biomarkers or therapeutic targets for TNBC patients. Thrombomodulin (TM) plays a role in cancer progression and metastasis in many different cancers. However, the role of TM in TNBC is not yet fully understood. First, silenced-TM in MDA-MB-231 cells caused an increase in proliferative and metastatic activity. In contrast, overexpression of TM in Hs578T cells caused a reduction in proliferation, invasion, and migration rate. Using RNA-seq analysis, we found that Integrin beta 3 (ITGB3) expression may be a downstream target of TM. Furthermore, we found an increase in ITGB3 levels in TM-KD cells by QPCR and western blot analysis but a decrease in ITGB3 levels in TM-overexpressing cells. We found phospho-smad2/3 levels were increased in TM-KD cells but decreased in TM-overexpressing cells. This implies that TM negatively regulates ITGB3 levels through the activation of the smad2/3 pathway. Silencing ITGB3 in TM-KD cells caused a decrease in proliferation and migration. Finally, we found that higher ITGB3 levels were correlated with poor overall survival and relapse-free survival in patients with TNBC. Our results indicated a novel regulatory relationship between TM and ITGB3 in TNBC.

Screening a DNA Aptamer Specifically Targeting Integrin β3 and Partially Inhibiting Tumor Cell Migration

Due to its key roles in malignant tumor progression and reprograming of the tumor microenvironment, integrin β3 has attracted great attention as a new target for tumor therapy. However, the structure-function relationship of integrins β3 remains incompletely understood, leading to the shortage of specific and effective targeting probes. This work uses a purified extracellular domain of integrin β3 and integrin β3-positive cells to screen aptamers, specifically targeting integrin β3 in the native conformation on live cells through the SELEX approach. Following meticulous truncation and characterization of the initial aptamer candidates, the optimized aptamer S10yh2 was produced, exhibiting a low equilibrium dissociation constant (Kd) in the nanomolar range. S10yh2 displays specific recognition of cancer cells with varying levels of integrin β3 expression and demonstrates favorable stability in serum. Subsequent analysis of docking sites revealed that S10yh2 binds to the seven amino acid residues located in the core region of integrin β3. The S10yh2 aptamer can downregulate the level of integrin heterodimer αvβ3 on integrin β3 overexpressed cancer cells and partially inhibit cell migration behavior. In summary, S10yh2 is a promising probe with a small size, simple synthesis, good stability, high binding affinity, and selectivity. It therefore holds great potential for investigating the structure-function relationship of integrins.

ITGB3 promotes cisplatin resistance in osteosarcoma tumors

OBJECTIVE

Osteosarcoma is the most malignant and common primary bone tumor with a high rate of recurrence that mainly occurs in children and young adults. Therefore, it is vital to facilitate the development of novel effective therapeutic means and improve the overall prognosis of osteosarcoma patients via a deeper understanding of the mechanisms of chemoresistance in osteosarcoma progression.

METHODS

In this research, the relationship between ITGB3 and the clinical characteristics of patients was detected through analysis of publicly available clinical datasets. The expression of ITGB3 was analysis in collected human osteosarcoma tissues. In addition, the potential functions of ITGB3 in the cisplatin resistance of osteosarcoma cells were investigated in vitro and in tumor xenotransplantation. Finally, the molecular mechanism of ITGB3 in the progression and recurrence of osteosarcoma were explored via transcriptome analysis.

RESULTS

ITGB3 was identified as a potential regulator of tumorigenicity and cisplatin resistance in relapsed osteosarcoma. Furthermore, the decreased osteosarcoma cell proliferation and migration ability in ITGB3 knockout osteosarcoma cells were related to increased apoptosis and slowing cell cycle progression. In addition, ITGB3 had a positive correlation with cisplatin resistance in cells and tumor xenografts in mice. Accordingly, ITGB3 performed the functions of proliferation and cisplatin resistance in osteosarcoma through the MAPK and VEGF signaling pathways.

CONCLUSION

Our results will contribute to a better understanding of the function and mechanism of ITGB3 in osteosarcoma cisplatin resistance and provide a novel therapeutic target to decrease cisplatin resistance and tumor recurrence in osteosarcoma patients.

Promotion of Lung Cancer Metastasis by SIRT2-Mediated Extracellular Protein Deacetylation

Acetylation of extracellular proteins has been observed in many independent studies where particular attention has been given to the dynamic change of the microenvironmental protein post-translational modifications. While extracellular proteins can be acetylated within the cells prior to their micro-environmental distribution, their deacetylation in a tumor microenvironment remains elusive. Here it is described that multiple acetyl-vWA domain-carrying proteins including integrin β3 (ITGB3) and collagen 6A (COL6A) are deacetylated by Sirtuin family member SIRT2 in extracellular space. SIRT2 is secreted by macrophages following toll-like receptor (TLR) family member TLR4 or TLR2 activation. TLR-activated SIRT2 undergoes autophagosome translocation. TNF receptor associated factor 6 (TRAF6)-mediated autophagy flux in response to TLR2/4 activation can then pump SIRT2 into the microenvironment to function as extracellular SIRT2 (eSIRT2). In the extracellular space, eSIRT2 deacetylates ITGB3 on aK416 involved in cell attachment and migration, leading to a promotion of cancer cell metastasis. In lung cancer patients, significantly increased serum eSIRT2 level correlates with dramatically decreased ITGB3-K416 acetylation in cancer cells. Thus, the extracellular space is a subcellular organelle-like arena where eSIRT2 promotes cancer cell metastasis via catalyzing extracellular protein deacetylation.

Precisely Targeted Nano-Controller of PD-L1 Level for Non-Small Cell Lung Cancer Spinal Metastasis Immunotherapy

Although immune checkpoint inhibitors (ICIs) have been widely applied to treat non-small cell lung cancer (NSCLC), a significant proportion of patients, especially those with spinal metastasis (NSCLC-SM), are insensitive to anti-programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) ICIs. A drug delivery nano-controller of PD-L1 that targets NSCLC-SM can solve this problem, however, none have been developed to date. In this study, it is shown that integrin β3 (β3-int) is strongly upregulated in NSCLC-SM. Its inhibitor RGDyK promotes PD-L1 ubiquitination, indicating the potential application of RGDyK as a new PD-L1 inhibitor in nano-controller and a targeting peptide for NSCLC-SM treatment. According to the synergistic effect of photodynamic therapy and ICIs on T-cell activation through the release of tumor antigens, RGDyK-modified and zinc protoporphyrin (ZnPP)-loaded mesoporous silicon nanoparticles (ZnPP@MSN-RGDyK) are fabricated. The ZnPP@MSN-RGDyK nanoparticles precisely target β3-int to inhibit PD-L1, exhibiting high photodynamic therapy efficiency, and excellent immunotherapeutic effects in an NSCLC-SM mouse model. Collectively, the findings indicate that ZnPP@MSN-RGDyK is a promising immunotherapeutic agent for treating NSCLC-SM.

Integrin β3 Promotes Resistance to EGFR-TKI in Non-Small-Cell Lung Cancer by Upregulating AXL through the YAP Pathway

Integrin β3 plays a key role in the resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI), but the development of integrin β3 inhibitors has been stalled due to the failure of phase III clinical trials for cancer treatment. Therefore, it is imperative to find a potentially effective solution to the problem of acquired resistance to EGFR-TKI for patients with integrin-β3 positive non-small-cell lung cancer (NSCLC) by exploring novel downstream targets and action mechanisms of integrin β3. In the present study, we observed that the expression of integrin β3 and AXL was significantly upregulated in erlotinib-resistant NSCLC cell lines, which was further confirmed clinically in tumor specimens from patients with NSCLC who developed acquired resistance to erlotinib. Through ectopic expression or knockdown, we found that AXL expression was positively regulated by integrin β3. In addition, integrin β3 promoted erlotinib resistance in NSCLC cells by upregulating AXL expression. Furthermore, the YAP pathway, rather than pathways associated with ERK or AKT, was involved in the regulation of AXL by integrin β3. To investigate the clinical significance of this finding, the current well-known AXL inhibitor R428 was tested, demonstrating that R428 significantly inhibited resistance to erlotinib, colony formation, epithelial–mesenchymal transformation and cell migration induced by integrin β3. In conclusion, integrin β3 could promote resistance to EGFR-TKI in NSCLC by upregulating the expression of AXL through the YAP pathway. Patients with advanced NSCLC, who are positive for integrin β3, might benefit from a combination of AXL inhibitors and EGFR-TKI therapy.

Transcriptome analysis reveals upregulation of immune response pathways at the invasive tumour front of metastatic seminoma germ cell tumours

Background

Testicular germ cell tumours (TGCTs) have a high metastasis rate. However, the mechanisms related to their invasion, progression and metastasis are unclear. Therefore, we investigated gene expression changes that might be linked to metastasis in seminomatous testicular germ cell tumour (STGCT) patients.

Methods

Defined areas [invasive tumour front (TF) and tumour centre (TC)] of non-metastatic (with surveillance and recurrence-free follow-up >2 years) and metastatic STGCTs were collected separately using laser capture microdissection. The expression of 760 genes related to tumour progression and metastasis was analysed using nCounter technology and validated with quantitative real-time PCR and enzyme-linked immunosorbent assay.

Results

Distinct gene expression patterns were observed in metastatic and non-metastatic seminomas with respect to both the TF and TC. Comprehensive pathway analysis showed enrichment of genes related to tumour functions such as inflammation, angiogenesis and metabolism at the TF compared to the TC. Remarkably, prominent inflammatory and cancer-related pathways, such as interleukin-6 (IL-6) signalling, integrin signalling and nuclear factor-κB signalling, were significantly upregulated in the TF of metastatic vs non-metastatic tumours.

Conclusions

IL-6 signalling was the most significantly upregulated pathway in metastatic vs non-metastatic tumours and therefore could constitute a therapeutic target for future personalised therapy. In addition, this is the first study showing intra- and inter-tumour heterogeneity in STGCT.

Stereospecific inhibition of AMPK by (R)-crizotinib induced changes to the morphology and properties of cancer and cancer stem cell-like cells

Crizotinib is used in the clinic for treating patients with ALK- or ROS1-positive non-small-cell lung carcinoma. The objective of the present study was to determine if crizotinib enantiomers could induce changes to the properties of cancer and cancer stem cell (CSC)-like cells at a high concentration (∼ 3 μM). While (R)-crizotinib induced changes in morphologies or sizes of cells, (S)-crizotinib did not. Pretreatment with (R)-crizotinib suppressed the proliferation of cancer or CSC-like cells in vitro and tumor growth in vivo. In vivo administration of (R)-crizotinib inhibited the growth of tumors formed from CSC-like cells by 72%. %. Along with the morphological changes induced by (R)-crizotinib, the expression levels of CD44 (NCI-H23 and HCT-15), ALDH1 (NCI-H460), nanog (PC-3), and Oct-4A (CSC-like cells), which appear to be specific marker proteins, were greatly changed, suggesting that changes in cellular properties accompanied the morphological changes in the cells. The expression levels of Snail, Slug, and E-cadherin were also greatly altered by (R)-crizotinib. Among several signal transduction molecules examined, AMPK phosphorylation appeared to be selectively inhibited by (R)-crizotinib. BML-275 (an AMPK inhibitor) and AMPKα2 siRNA efficiently induced morphological changes to all types of cells examined, suggesting that (R)-crizotinib might cause losses of characteristics of cancer or CSCs via inhibition of AMPK. These results indicate that (R)-crizotinib might be an effective anticancer agent that can cause alteration in cancer cell properties.

Shifting Gears in Precision Oncology-Challenges and Opportunities of Integrative Data Analysis

For decades, research relating to modification of host immunity towards antitumor response activation has been ongoing, with the breakthrough discovery of immune-checkpoint blockers. Several biomarkers with potential predictive value have been reported in recent studies for these novel therapies. However, with the plethora of therapeutic options existing for a given cancer entity, modern oncology is now being confronted with multifactorial interpretation to devise “the best therapy” for the individual patient. Into the bargain come the multiverse guidelines for established and emerging diagnostic biomarkers, as well as the complex interplay between cancer cells and tumor microenvironment, provoking immense challenges in the therapy decision-making process. Through this review, we present various molecular diagnostic modalities and techniques, such as genomics, immunohistochemistry and quantitative image analysis, which have the potential of becoming powerful tools in the development of an optimal treatment regime when analogized with patient characteristics. We will summarize the underlying complexities of these methods and shed light upon the necessary considerations and requirements for data integration. It is our hope to provide compelling evidence to emphasize on the need for inclusion of integrative data analysis in modern cancer therapy, and thereupon paving a path towards precision medicine and better patient outcomes.

CXCL12-mediated HOXB5 overexpression facilitates Colorectal Cancer metastasis through transactivating CXCR4 and ITGB3

Background: Metastasis is the major reason for the high mortality of colorectal cancer (CRC). However, the molecular mechanism underlying CRC metastasis remains unclear. Here, we report a novel role of homeobox B5 (HOXB5), a member of the HOX family, in promoting CRC metastasis. Method: The expression of HOXB5 and its target genes were examined by immunohistochemistry in human CRC. Chromatin immunoprecipitation and luciferase reporter assays were performed to measure the transcriptional regulation of target genes by HOXB5. The metastatic capacities of CRC cells were evaluated by in vivo lung and liver metastatic models. Results: The elevated expression of HOXB5 was positively correlated with distant metastasis, higher AJCC stage, and poor prognosis in CRC patients. HOXB5 expression was an independent and significant risk factor for the recurrence and survival in CRC patients. Overexpression of HOXB5 promoted CRC metastasis by transactivating metastatic related genes, C-X-C motif chemokine receptor 4 (CXCR4) and integrin subunit beta 3 (ITGB3). C-X-C motif chemokine ligand 12 (CXCL12), which is the ligand of CXCR4, upregulated HOXB5 expression through the extracellular regulated protein kinase (ERK)/ETS proto-oncogene 1, transcription factor (ETS1) pathway. The knockdown of HOXB5 decreased CXCL12-enhanced CRC metastasis. Furthermore, AMD3100, a specific CXCR4 inhibitor, significantly suppressed HOXB5-mediated CRC metastasis. HOXB5 expression was positively correlated with CXCR4 and ITGB3 expression in human CRC tissues, and patients with positive co-expression of HOXB5/CXCR4, or HOXB5/ITGB3 exhibited the worst prognosis. Conclusion: Our study implicates HOXB5 as a prognostic biomarker in CRC, and defines a CXCL12-HOXB5-CXCR4 positive feedback loop that plays an important role in promoting CRC metastasis.

Integrin β3 promotes cardiomyocyte proliferation and attenuates hypoxia-induced apoptosis via regulating the PTEN/Akt/mTOR and ERK1/2 pathways

Objective: Integrin β3 is one of the main integrin heterodimer receptors on the surface of cardiac myocytes. Our previous studies showed that hypoxia induces apoptosis and increases integrin β3 expression in cardiomyocytes. However, the exact mechanism by which integrin β3 protects against apoptosis remains unclear. Hence, the present investigation aimed to explore the mechanism of integrin β3 in cardiomyocyte proliferation and hypoxia-induced cardiomyocyte apoptosis. Methods: Stable cells and in vivo acute and chronic heart failure rat models were generated to reveal the essential role of integrin β3 in cardiomyocyte proliferation and apoptosis. Western blotting and immunohistochemistry were employed to detect the expression of integrin β3 in the stable cells and rat cardiac tissue. Flow cytometer was used to investigate the role of integrin β3 in hypoxia-induced cardiomyocyte apoptosis. Confocal microscopy was used to detect the localization of integrin β3 and integrin αv in cardiomyocytes. Results: A cobaltous chloride-induced hypoxic microenvironment stimulated cardiomyocyte apoptosis and increased integrin β3 expression in H9C2 cells, AC16 cells, and cardiac tissue from acute and chronic heart failure rats. The overexpression of integrin β3 promoted cardiomyocyte proliferation, whereas silencing integrin β3 expression resulted in decreased cell proliferation in vitro. Furthermore, knocking down integrin β3 expression using shRNA or the integrin β3 inhibitor cilengitide exacerbated cobaltous chloride-induced cardiomyocyte apoptosis, whereas overexpression of integrin β3 weakened cobaltous chloride-induced cardiomyocytes apoptosis. We found that integrin β3 promoted cardiomyocytes proliferation through the regulation of the PTEN/Akt/mTOR and ERK1/2 signaling pathways. In addition, we found that knockdown of integrin αv or integrin β1 weakened the effect of integrin β3 in cardiomyocyte proliferation. Conclusion: Our findings revealed the molecular mechanism of the role of integrin β3 in cardiomyocyte proliferation and hypoxia-induced cardiomyocyte apoptosis, providing new insights into the mechanisms underlying myocardial protection.

The YAP1-NMU Axis Is Associated with Pancreatic Cancer Progression and Poor Outcome: Identification of a Novel Diagnostic Biomarker and Therapeutic Target

Yes-associated protein (YAP)-1 is highly upregulated in pancreatic cancer and associated with tumor progression. However, little is known about the role of YAP1 and related genes in pancreatic cancer. Here, we identified target genes regulated by YAP1 and explored their role in pancreatic cancer progression and the related clinical implications. Analysis of different pancreatic cancer databases showed that Neuromedin U (NMU) expression was positively correlated with YAP1 expression in the tumor group. The Cancer Genome Atlas data indicated that high YAP1 and NMU expression levels were associated with poor mean and overall survival. YAP1 overexpression induced NMU expression and transcription and promoted cell motility in vitro and tumor metastasis in vivo via upregulation of epithelial-mesenchymal transition (EMT), whereas specific inhibition of NMU in cells stably expressing YAP1 had the opposite effect in vitro and in vivo. To define this functional association, we identified a transcriptional enhanced associate domain (TEAD) binding site in the NMU promoter and demonstrated that YAP1-TEAD binding upstream of the NMU gene regulated its transcription. These results indicate that the identified positive correlation between YAP1 and NMU is a potential novel drug target and biomarker in metastatic pancreatic cancer.