Correlation between beta1 integrin expression and prognosis in clinically localized prostate cancer

The Potential of Extracellular Matrix- and Integrin Adhesion Complex-Related Molecules for Prostate Cancer Biomarker Discovery

Prostate cancer is among the top five cancer types according to incidence and mortality. One of the main obstacles in prostate cancer management is the inability to foresee its course, which ranges from slow growth throughout years that requires minimum or no intervention to highly aggressive disease that spreads quickly and resists treatment. Therefore, it is not surprising that numerous studies have attempted to find biomarkers of prostate cancer occurrence, risk stratification, therapy response, and patient outcome. However, only a few prostate cancer biomarkers are used in clinics, which shows how difficult it is to find a novel biomarker. Cell adhesion to the extracellular matrix (ECM) through integrins is among the essential processes that govern its fate. Upon activation and ligation, integrins form multi-protein intracellular structures called integrin adhesion complexes (IACs). In this review article, the focus is put on the biomarker potential of the ECM- and IAC-related molecules stemming from both body fluids and prostate cancer tissue. The processes that they are involved in, such as tumor stiffening, bone turnover, and communication via exosomes, and their biomarker potential are also reviewed.

The characteristics and the multiple functions of integrin β1 in human cancers

Integrins, which consist of two non-covalently linked α and β subunits, play a crucial role in cell-cell adhesion and cell-extracellular matrix (ECM) interactions. Among them, integrin β1 is the most common subunit and has emerged as a key mediator in cancer, influencing various aspects of cancer progression, including cell motility, adhesion, migration, proliferation, differentiation and chemotherapy resistance. However, given the complexity and sometimes contradictory characteristics, targeting integrin β1 for therapeutics has been a challenge. The emerging understanding of the mechanisms regulating by integrin β1 may guide the development of new strategies for anti-cancer therapy. In this review, we summarize the multiple functions of integrin β1 and signaling pathways which underlie the involvement of integrin β1 in several malignant cancers. Our review suggests the possibility of using integrin β1 as a therapeutic target and highlights the need for patient stratification based on expression of different integrin receptors in future clinical studies.

Integrin expression in correlation to clinicopathological features and prognosis of prostate cancer: A systematic review and meta-analysis

BACKGROUND

The prompt identification of patients with poor prognosis is essential in order to improve the treatment outcomes in prostate cancer (CaP); as a novel approach, several molecular markers, including integrins, have been discussed as prognostic biomarkers. Our aim was to comprehensively examine aberrant expression of integrins in correlation with clinicopathological features and prognosis in CaP by synthesizing all available evidence, in a systematic review and meta-analysis.

METHODS

A systematic review and meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. Scientific literature databases (Pubmed, Embase, and Scopus) were systematically searched until May 10, 2020. Random-effects (DerSimonian-Laird) models were used to estimate pooled odds ratios (ORs) for cross-sectional correlations with clinicopathological characteristics and relative risks for longitudinal associations with prognosis.

RESULTS

Fourteen studies were included with a total number of 3,194 CaP cases examined (13 cross-sectional and four longitudinal cohort study arms). Correlation of low expression of α₆ (pooled OR = 0.10, 95% confidence interval [CI]: 0.04-0.28, P < 0.001) and β₁ (pooled OR = 0.45; 95% CI: 0.21-1.00, P = 0.049) integrin with high Gleason score was noted. A borderline trend between reduced expression of α₆ integrin and an advanced clinical stage of CaP (pooled OR = 0.48; 95% CI: 0.22-1.03, P = 0.06) was observed. No associations with biochemical recurrence and survival were documented.

CONCLUSIONS

Evidence on the association of low expression of integrins α₆ and β₁ and more advanced CaP exist, whereas significant results on survival were not documented; further studies are warranted.

Integrin subunit β1 and laminin γ1 chain expression: a potential prognostic biomarker in cervical cancer

Aim: The aim of this study was to analyze the prognostic value of integrin subunit β1 and laminin γ1 chain in patients with cervical cancer (CC). Materials & methods: The study included 96 samples. Cytological diagnosis, human papillomavirus (HPV) genotyping, HPV integration status and integrin subunit β1 and laminin γ1 chain expressions were performed or determined using Papanicolaou smear, INNO-LiPA^® Genotyping Extra Kit, in situ hybridization, and immunocytochemistry, respectively. The association between variables was calculated using chi-squared and Fisher's exact test; logistic regression analysis was performed to calculate odds ratios and CI at 95%. Results: Our results show that integrin subunit β1 and laminin γ1 chain expressions increase according to tumor progression. Integrin subunit β1 and laminin γ1 chain expressions are associated with cytological diagnosis (p < 0.001 and p = 0.001, respectively) and laminin γ1 chain expression with the integration status of HPV (p < 0.001). Moderate/high expressions of integrin subunit β1 and laminin γ1 chain were correlated with overall survival and increased risk of CC (6.86 and 3.75, respectively), the odds ratio was 12.91 when the moderate/high expression of integrin subunit β1 and laminin γ1 chain were combined. Conclusion: Our results suggest that integrin subunit β1 and laminin γ1 chain expressions could be a prognostic biomarker in CC.

Targeting Integrins in Cancer Nanomedicine: Applications in Cancer Diagnosis and Therapy

Due to advancements in nanotechnology, the application of nanosized materials (nanomaterials) in cancer diagnostics and therapeutics has become a leading area in cancer research. The decoration of nanomaterial surfaces with biological ligands is a major strategy for directing the actions of nanomaterials specifically to cancer cells. These ligands can bind to specific receptors on the cell surface and enable nanomaterials to actively target cancer cells. Integrins are one of the cell surface receptors that regulate the communication between cells and their microenvironment. Several integrins are overexpressed in many types of cancer cells and the tumor microvasculature and function in the mediation of various cellular events. Therefore, the surface modification of nanomaterials with integrin-specific ligands not only increases their binding affinity to cancer cells but also enhances the cellular uptake of nanomaterials through the intracellular trafficking of integrins. Moreover, the integrin-specific ligands themselves interfere with cancer migration and invasion by interacting with integrins, and this finding provides a novel direction for new treatment approaches in cancer nanomedicine. This article reviews the integrin-specific ligands that have been used in cancer nanomedicine and provides an overview of the recent progress in cancer diagnostics and therapeutic strategies involving the use of integrin-targeted nanomaterials.

Prognostic value of increased integrin-beta 1 expression in solid cancers: a meta-analysis

Integrin-beta 1 (ITGB1) is aberrantly overexpressed or downregulated in solid cancers; however, its prognostic value remains controversial. Therefore, we conducted a meta-analysis to explore whether ITGB1 expression is correlated with overall survival (OS) and the clinicopathological characteristics of patients with solid cancers. We systematically searched the PubMed, Embase, and Web of Science databases for eligible studies published up to June 1, 2017. In total, 22 studies involving 3,666 patients were included. A sensitivity analysis was performed to assess the validity and reliability of the pooled OS. Among the 22 studies, 7 focused on lung cancer, 3 focused on colorectal cancer, 6 focused on breast cancer, 3 involved melanoma, and 3 involved pancreatic cancer. The pooled results showed that high ITGB1 expression was significantly associated with worse OS in lung cancer (pooled hazard ratio [HR]=1.78, 95% CI: 1.19–2.65, p<0.05) and breast cancer (pooled HR=1.88, 95% CI: 1.46–2.42, p<0.01). In addition, a significant association was observed between high ITGB1 expression and disease-free survival in breast cancer (pooled HR=1.63, 95% CI: 1.17–2.25, p<0.001) and pancreatic cancer (pooled HR=2.49, 95% CI: 1.35–4.61, p<0.001). However, high ITGB1 expression was not related to OS in colorectal cancer, pancreatic cancer, or melanoma. The pooled HRs used to evaluate the prognostic value of increased ITGB1 expression in lung cancer, breast cancer, and pancreatic cancer were not significantly altered, which indicates that the pooled results were robust. The results of this study indicate that the prognostic value of decreased ITGB1 expression varies among solid cancers.

β1 and β3 integrins in breast, prostate and pancreatic cancer: A novel implication

Integrins are transmembrane glycoproteins that consist of an α and a β subunit. Specific integrin heterodimers preferentially bind to distinct extracellular matrix (ECM) proteins to affect the characteristics of cells or the components of the ECM. Among the different integrins, β1 and β3 integrins serve essential roles in the progression of different cancer-associated processes, including the initiation, proliferation, survival, migration and invasion. Furthermore, previous studies have revealed a ratio between these two integrins in cancer cells, which also demonstrated that the functions of these two integrins are paradoxical. This indicated that the proliferation and metastasis of cancer cells are not always parallel and may be considered independently maintained. Additionally, the present review may assist in understanding certain aspects of cancer, and in making clinical decisions in a novel and more comprehensive manner.

Correlation between Chromosome 9p21 Locus Deletion and Prognosis in Clinically Localized Prostate Cancer

Background

Some studies have reported that deletions at chromosome arm 9p occur frequently and represent a critical step in carcinogenesis of some neoplasms. Our aim was to evaluate the deletion of locus 9p21 and chromosomes 3, 7 and 17 in localized prostate cancer (PC) and correlate these alterations with prognostic factors and biochemical recurrence after surgery.

Methods

We retrospectively evaluated surgical specimens from 111 patients with localized PC who underwent radical prostatectomy. Biochemical recurrence was defined as a prostate-specific antigen (PSA) >0.2 ng/mL and the mean postoperative follow-up was 123 months. The deletions were evaluated using fluorescence in situ hybridization with centromeric and locus-specific probes in a tissue microarray containing 2 samples from each patient. We correlated the occurrence of any deletion with pathological stage, Gleason score, ISUP grade group, PSA and biochemical recurrence.

Results

We observed a loss of any probe in only 8 patients (7.2%). The most common deletion was the loss of locus 9p21, which occurred in 6.4% of cases. Deletions of chromosomes 3, 7 and 17 were observed in 2.3%, 1.2% and 1.8% patients, respectively. There was no correlation between chromosome loss and Gleason score, ISUP, PSA or stage. Biochemical recurrence occurred in 83% cases involving 9p21 deletions. Loss of 9p21 locus was significantly associated with time to recurrence (p = 0.038).

Conclusions

We found low rates of deletion in chromosomes 3, 7 and 17 and 9p21 locus. We observed that 9p21 locus deletion was associated with worse prognosis in localized PC treated by radical prostatectomy.

Functional polymorphisms of ITGB1 are associated with clinical outcome of Chinese patients with resected colorectal cancer

PURPOSE

Integrin β1 (ITGB1) has been recognized to play a major role in tumor growth, invasion and metastasis. However, effects of single-nucleotide polymorphisms (SNPs) in ITGB1 gene on the prognosis of patients with colorectal cancer (CRC) have not been reported.

METHODS

A total of 372 patients with resected colorectal adenocarcinoma were enrolled in our study. Three functional SNPs (rs2230395, rs1187075 and rs1187076) in ITGB1 were selected and genotyped using the Sequenom iPLEX genotyping system.

RESULTS

We identified two SNPs (rs2230395 and rs1187075) in ITGB1 gene to be significantly associated with CRC overall survival (OS). Compared with the homozygous wild-type (AA) and heterozygous variant (AC), rs2230395 homozygous variant (CC) conferred a 1.55-fold (95 % CI 1.00-2.41, P = 0.049) increased risk of death. Similar result was obtained for homozygous variant (AA) in rs1187075 with a 1.62-fold (95 % CI 1.08-2.42, P = 0.020). In stratified analysis, this association in rs2230395 remained to be significant in patients receiving chemotherapy, but not in those without chemotherapy. We further evaluated the effects of chemotherapy on CRC survival in subgroups stratified by rs2230395 and rs1187075 genotypes. We found that chemotherapy resulted in a significantly better OS in patients with the homozygous wild-type (WW) or heterozygous variant (WV) genotype in both rs2230395 and rs1187075 when compared with patients with homozygous variant (VV) genotype.

CONCLUSIONS

Our data suggest that ITGB1 SNPs might be a prognostic biomarker for CRC patients, especially in those receiving chemotherapy. Our findings warrant validation in larger independent populations.

To Target or Not to Target: Active vs. Passive Tumor Homing of Filamentous Nanoparticles Based on Potato virus X

Nanoparticles are promising platforms for the diagnosis and treatment of cancer. Diverse classes and shapes of materials have been investigated to establish design principles that achieve the effective partitioning of medical cargos between tumors and healthy tissues. Molecular targeting strategies combined with specific nanoparticle shapes confer tissue-specificity on the carriers, allowing the cell-specific delivery of cargos. We recently developed a filamentous platform technology in which the plant virus Potato virus X (PVX) was used as a scaffold. These particles are flexible 515 × 13 nm filaments that encourage passive tumor homing. Here we sought to advance the PVX platform by including a molecular targeting strategy based on cyclic RGD peptides, which specifically bind to integrins upregulated on tumor cells, neovasculature, and metastatic sites. Although the RGD-targeted filaments outperformed the PEGylated stealth filaments in vitro, enhanced tumor cell targeting did not translate into improved tumor homing in vivo in mouse tumor models. The RGD-PVX and PEG-PVX filaments showed contrasting biodistribution profiles. Both formulations were cleared by the liver and spleen, but only the stealth filaments accumulated in tumors, whereas the RGD-targeted filaments were sequestered in the lungs. These results provide insight into the design principles for virus-based nanoparticles that promote the delivery of medical cargos to the appropriate cell types.