Fibronectin Regulation of Integrin B1 and SLUG in Circulating Tumor Cells

Survival mechanisms of circulating tumor cells and their implications for cancer treatment

Metastasis remains the principal trigger for relapse and mortality across diverse cancer types. Circulating tumor cells (CTCs), which originate from the primary tumor or its metastatic sites, traverse the vascular system, serving as precursors in cancer recurrence and metastasis. Nevertheless, before CTCs can establish themselves in the distant parenchyma, they must overcome significant challenges present within the circulatory system, including hydrodynamic shear stress (HSS), oxidative damage, anoikis, and immune surveillance. Recently, there has been a growing body of compelling evidence suggesting that a specific subset of CTCs can persist within the bloodstream, but the precise mechanisms of their survival remain largely elusive. This review aims to present an outline of the survival challenges encountered by CTCs and to summarize the recent advancements in understanding the underlying survival mechanisms, suggesting their implications for cancer treatment.

Molecular biomarkers in prostate cancer tumorigenesis and clinical relevance

Prostate cancer (PCa) is the second most frequent type of cancer in men and assessing circulating tumor cells (CTCs) by liquid biopsy is a promising tool to help in cancer early detection, staging, risk of recurrence evaluation, treatment prediction and monitoring. Blood-based liquid biopsy approaches enable the enrichment, detection and characterization of CTCs by biomarker analysis. Hence, comprehending the molecular markers, their role on each stage of cancer development and progression is essential to provide information that can help in future implementation of these biomarkers in clinical assistance. In this review, we studied the molecular markers most associated with PCa CTCs to better understand their function on tumorigenesis and metastatic cascade, the methodologies utilized to analyze these biomarkers and their clinical significance, in order to summarize the available information to guide researchers in their investigations, new hypothesis formulation and target choice for the development of new diagnostic and treatment tools.

Recent Advances in Microfluidic Platform for Physical and Immunological Detection and Capture of Circulating Tumor Cells

CTCs (circulating tumor cells) are well-known for their use in clinical trials for tumor diagnosis. Capturing and isolating these CTCs from whole blood samples has enormous benefits in cancer diagnosis and treatment. In general, various approaches are being used to separate malignant cells, including immunomagnets, macroscale filters, centrifuges, dielectrophoresis, and immunological approaches. These procedures, on the other hand, are time-consuming and necessitate multiple high-level operational protocols. In addition, considering their low efficiency and throughput, the processes of capturing and isolating CTCs face tremendous challenges. Meanwhile, recent advances in microfluidic devices promise unprecedented advantages for capturing and isolating CTCs with greater efficiency, sensitivity, selectivity and accuracy. In this regard, this review article focuses primarily on the various fabrication methodologies involved in microfluidic devices and techniques specifically used to capture and isolate CTCs using various physical and biological methods as well as their conceptual ideas, advantages and disadvantages.

Decreased endostatin in db/db retinas is associated with optic disc intravitreal vascularization

Endostatin, a naturally cleaved fragment of type XVIII collagen with antiangiogenic activity, has been involved in the regulation of neovascularization during diabetic retinopathy. Here, the intracellular distribution of endostatin in healthy mouse and human neuroretinas has been analyzed. In addition, to study the effect of experimental hyperglycemia on retinal endostatin, the db/db mouse model has been used. Endostatin protein expression in mouse and human retinas was studied by immunofluorescence and Western blot, and compared with db/db mice. Eye fundus angiography, histology, and immunofluorescence were used to visualize mouse retinal and intravitreal vessels. For the first time, our results revealed the presence of endostatin in neurons of mouse and human retinas. Endostatin was mainly expressed in bipolar cells and photoreceptors, in contrast to the optic disc, where endostatin expression was undetectable. Diabetic mice showed a reduction of endostatin in their retinas associated with the appearance of intravitreal vessels at the optic disc in 50% of db/db mice. Intravitreal vessels showed GFAP positive neuroglia sheath, basement membrane thickening by collagen IV deposition, and presence of MMP-2 and MMP-9 in the vascular wall. All together, these results point that decreased retinal endostatin during experimental diabetes is associated with optic disc intravitreal vascularization. Based on their phenotype, these intravitreal vessels could be neovessels. However, it cannot be ruled out the possibility that they may also represent persistent hyaloid vessels.

Characterization of TGFβ-associated molecular features and drug responses in gastrointestinal adenocarcinoma

Background

Gastrointestinal adenocarcinoma (GIAD) has caused a serious disease burden globally. Targeted therapy for the transforming growth factor beta (TGF-β) signaling pathway is becoming a reality. However, the molecular characterization of TGF-β associated signatures in GIAD requires further exploration.

Methods

Multi-omics data were collected from TCGA and GEO database. A pivotal unsupervised clustering for TGF-β level was performed by distinguish status of TGF-β associated genes. We analyzed differential mRNAs, miRNAs, proteins gene mutations and copy number variations in both clusters for comparison. Enrichment of pathways and gene sets were identified in each type of GIAD. Then we performed differential mRNA related drug response by collecting data from GDSC. At last, a summarized deep neural network for TGF-β status and GIADs was constracted.

Results

The TGF-β^high group had a worse prognosis in overall GIAD patients, and had a worse prognosis trend in gastric cancer and colon cancer specifically. Signatures (including mRNA and proteins) of the TGF-β^high group is highly correlated with EMT. According to miRNA analysis, miR-215-3p, miR-378a-5p, and miR-194-3p may block the effect of TGF-β. Further genomic analysis showed that TGF-β^low group had more genomic changes in gastric cancer, such as TP53 mutation, EGFR amplification, and SMAD4 deletion. And drug response dataset revealed tumor-sensitive or tumor-resistant drugs corresponding to TGF-β associated mRNAs. Finally, the DNN model showed an excellent predictive effect in predicting TGF-β status in different GIAD datasets.

Conclusions

We provide molecular signatures associated with different levels of TGF-β to deepen the understanding of the role of TGF-β in GIAD and provide potential drug possibilities for therapeutic targets in different levels of TGF-β in GIAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01869-4.

Research Progress for the Clinical Application of Circulating Tumor Cells in Prostate Cancer Diagnosis and Treatment

Prostate cancer is a life-threatening and highly heterogeneous malignancy. In the past decade, circulating tumor cells (CTCs) have been suggested to play a critical role in the occurrence and progression of prostate cancer. In particular, as the “seed” of the cancer metastasis cascade, CTCs determine numerous biological behaviors, such as tumor invasion into adjacent tissues and migration to distant organs. Many studies have shown that CTCs are necessary in the processes of tumor progression, including tumorigenesis, invasion, metastasis, and colonization. Furthermore, CTCs express various biomarkers relevant to prostate cancer and thus can be applied clinically in noninvasive tests. Moreover, CTCs can serve as potential prognostic targets in prostate cancer due to their roles in regulating many processes associated with cancer metastasis. In this review, we discuss the isolation and detection of CTCs as predictive markers of prostate cancer, and we discuss their clinical application in the diagnosis and prognosis of prostate cancer and in monitoring the response to treatment and the prediction of metastasis.

Changes in serum fibronectin levels predict tumor recurrence in patients with early hepatocellular carcinoma after curative treatment

Fibronectin, a matrix glycoprotein aberrantly expressed in various tumor cells, is a known candidate biomarker for the early diagnosis of hepatocellular carcinoma (HCC). In this study, we investigated whether serum fibronectin levels could predict tumor recurrence in patients with early-stage HCC after curative treatment. A total of 83 patients who showed complete response after initial curative treatment were included. The levels of serum fibronectin at baseline and 4–6 weeks after initial treatment were analyzed with regard to their associations with recurrence. Multivariate logistic regression analyses were performed to construct a prognostic nomogram. Baseline fibronectin levels were not significantly correlated with tumor size, number, stage, and serum α-fetoprotein levels. However, decrease in serum fibronectin levels after treatment was significantly associated with reduced HCC recurrence in multivariate logistic regression (odds ratio, 0.009; p < 0.001). Furthermore, a nomogram consisting of gender and changes in serum fibronectin showed a good discriminatory capability for the prediction of HCC recurrence with an area under the receiver-operating curve of 0.87. In conclusion, changes in serum fibronectin levels may be a surrogate indicator for assessment of treatment response in patients with early HCC after curative treatment.

Arsenic trioxide-increased MDCK cells proliferation requires activator protein 1-mediated increase of the sodium/proton exchanger 1 activity

The release of protons (H⁺) occurs via the Na⁺/H⁺ exchanger isoform 1 (NHE1) leading to a stable intracellular pH (pHi) in MDCK cells. Chronic intake of arsenic trioxide (ATO), in the drinking water, associated with higher morbidity and mortality in neoplastic tissues. ATO increased NHE1 expression and activity, resulting in intracellular alkalization and higher MDCK cells proliferation. Since the pro-proliferative transcription factor activator protein 1 (AP-1) gets activated by al alkaline intracellular pH, a phenomenon paralleled by higher NHEs activity, we asked whether ATO-increased MDCK cells proliferation involves AP-1-dependent NHE1 activation. Cells were exposed (48 h) to ATO (0.05 μmol/L), SR11302 (1 μmol/L, AP-1 inhibitor), HOE-694 (100 nmol/L, NHE1 inhibitor) and EIPA (50 μmol/L, NHE1/NHE3 inhibitor) in the presence of S3226 (10 μmol/L, NHE3 inhibitor), concanamycin A (0.1 μmol/L, V-ATPases inhibitor), and Schering (10 μmol/L, H⁺/K⁺-ATPase inhibitor). [³H]Thymidine incorporation, cell counting, wound healing assay, and AP-1 activity were determined. The pHi was measured in cells pre-loaded (10 min) with 2,7-bicarboxyethyl-5,6-carboxyfluorescein acetoxymethyl ester (12 mmol/L) and exposed to NH₄Cl (20 mmol/L). Basal pHi and recovery rate (dpHi/dt), intracellular buffer capacity (βi) and H⁺ flux (J_H⁺) were determined. NHE1 protein abundance was measured by Western blotting and immunofluorescence. ATO increased the cell growth (1.5 fold), basal pHi (0.4 pHi units), dpHi/dt (1.8 fold), J_H⁺ (1.4 fold), AP-1 activity and NHE1 protein abundance (1.3 fold). ATO also increased (1.5 fold) the nuclear/perinuclear NHE1 immunosignal. SR11302 and HOE-694 blocked ATO effects. Thus, ATO-increased proliferation resulted from AP-1-dependent NHE1 activation in MDCK cells.

Relationship between circulating tumor cells undergoing EMT and short-term efficacy following interventional treatment in patients with hepatocellular carcinoma

Objective

A growing number of studies have indicated that epithelial-mesenchymal transition (EMT) phenotypes and the number of circulating tumor cells (CTCs) are significant indicators of tumor characteristics and treatment efficacy, and thus have a broad range of potential applications in the diagnosis and treatment of malignant tumors. The value of data on CTC phenotypes and CTC counts in the diagnosis of hepatocellular carcinoma (HCC) and assessment of efficacy after comprehensive interventional therapy remains unclear.

Methods

Data of 107 patients who exhibited space-occupying lesions in the liver on enhanced CT/MRI scans at the Guangdong Provincial People’s Hospital (a tertiary medical center) between August 2017 and October 2018, were retrospectively analyzed. All enrolled patients were treated with transcatheter arterial chemoembolization (TACE) combined with microwave ablation (MWA). An imFISH CTC assay was used to isolate and count CTCs with different EMT phenotypes in the patients’ peripheral blood, which facilitated an analysis of the value of CTC phenotype and CTC count data in the diagnosis or treatment of HCC.

Results

The CTC count and EMT phenotypes in HCC patients were not associated with patient characteristics such as age, sex, Hepatitis B Virus (HBV)-DNA status, alcohol consumption history, Aspartate Transaminase (AST) to Platelet Ratio Index (APRI) score, Eastern Cooperative Oncology Group (ECOG) score, Child-Pugh score, alpha-fetoprotein (AFP), number and size of tumors, vascular invasion, or metastasis (P ​> ​0.05). The CTC count and EMT phenotypes in HCC patients before treatment were not predictive of short-term efficacy (P ​> ​0.05). Comprehensive interventional therapy reduced the total CTC count and mesenchymal CTC count (P ​= ​0.034 and 0.022, respectively).

Conclusion

TACE in combination with ablation reduced the total CTC count and mesenchymal CTC count. The CTC count and EMT phenotypes may be associated with long-term efficacy.

Circulating Tumor Cell Migration Requires Fibronectin Acting through Integrin B1 or SLUG

Fibronectin (FN1) is an extracellular matrix protein gaining increasing attention for its multifaceted roles in cancer progression. Using our recently established circulating tumor cell (CTC) lines, we had demonstrated increased FN1 expression and enhanced migration in CTC lines, in comparison to primary tumor cell lines. Whether increased FN1 expression is directly required for CTC migration, and the specific role of FN1’s regulation of integrin B1 (ITGB1) and SLUG (SNAI2) in CTC migration remains unclear. Here, for the first time, we report that the knockdown of FN1, ITGB1, or SLUG expression in CTCs leads to a significant decrease in CTC migration. Knocking down two or all three of these proteins simultaneously did not further inhibit migration. We observed a corresponding increase in CTC migration when recombinant FN1 was added to CTCs. This effect was significantly impeded by prior knockdown of ITGB1 or SLUG. Using knock down experiments and western blotting analysis, we confirmed FN1’s regulation of ITGB1 and SLUG to occur via two separate, independent pathways. Consequently, we can conclude that FN1-dependent enhanced migration of CTCs requires downstream signaling through either ITGB1 or SLUG and that FN1 regulation of ITGB1 and SLUG may have important implications for cancer progression and metastasis.

Fibronectin promotes tumor cells growth and drugs resistance through a CDC42-YAP-dependent signaling pathway in colorectal cancer

Fibronectin (FN) is a high-molecular-weight glycoprotein of the extracellular matrix (ECM) that binds to membrane-spanning receptor proteins or other elements in ECM. The expression of FN could be involved in the cancer cells proliferation or migration, and the molecular mechanisms responsible for FN induced protumor signals begin to be elucidated. Here, we report that the elevated expression of FN was observed in those chemoresistant tumor tissues from patients with colorectal cancer. Consistently, FN culture significantly strengthened the proliferation of colorectal cancer cells, induced the colorectal tumor sustained growth and drug resistance in vitro and in vivo. In mechanism, FN could bind to integrin αvβ1, resulting the downstream cell division cycle 42/yes-associated protein 1 (CDC42/YAP-1) signaling pathway activation. The activation of CDC42/YAP-1 signal induces the upregulation of transcription factor SOX2, causing the sustained growth and drugs resistance in colorectal cancer. Blockade of integrin αvβ1 significantly suppressed the colorectal cancer growth and drugs resistance development in vitro and in vivo, which provides a new target for clinical colorectal cancer treatment.