Higher Expression of Talin-1 is Associated With Less Aggressive Tumor Behavior in Pancreatic Cancer.

Talin-1 is one of the major scaffold proteins in focal adhesions playing a vital role in cell migration, metastasis, and cancer progression. Although studies regarding the importance of Talin-1 in cancer have rapidly developed, its prognostic and diagnostic value still remain unsatisfying in pancreatic cancer (PC). Therefore, the present study aims to investigate the expression, clinical significance, as well as the prognostic and diagnostic value of Talin-1 in different types of PC. Bioinformatic analysis was applied to determine the clinical importance and biological role of Talin-1 expression in PC tumors and the normal adjacent samples. The expression patterns, clinical significance, prognosis, and diagnosis value of Talin-1 were evaluated in tissue microarrays (TMAs) of 190 PC samples including 170 pancreatic ductal adenocarcinoma (PDAC), and 20 pancreatic neuroendocrine tumors (PNET), along with 24 adjacent normal tissues using immunohistochemistry (IHC). The results indicated that the expression of Talin-1 was upregulated in tumor cells compared with adjacent normal tissues. A statistically significant association was observed between the higher cytoplasmic expression of Talin-1 and lower histologic grade (P<0.001) in PDAC samples. Further, our findings indicated an inverse significant correlation between cytoplasmic expression of Talin-1 and recurrence (P=0.014) in PNET samples. No significant association was observed between the cytoplasmic expression of Talin-1 and survival outcomes as well as diagnostic accuracy. In conclusion, our observations demonstrated that a higher cytoplasmic level of Talin-1 protein was significantly associated with less aggressive tumor behaviors in PC samples. Nevertheless, further investigations are required to explore the prognostic plus diagnostic value, and mechanism of action of Talin-1 in pancreatic cancer.

The Effects of Severe Symptoms of SARS-CoV-2 Infections on the Anti/Proapoptotic Molecules: A 6-Month Cohort Study.

The plausible effects of SARS-CoV-2 infection on the expression of anti/proapoptotic molecules have been suspected. This cohort study examined the expression of p53, Bcl-2, Bid, Bak, and Bax molecules, the genes associated with induction or inhibition of apoptosis, in the SARS-CoV-2-infected patients with severe and mild symptoms in an Iranian population. In this 6-month cohort study, the expression of p53, Bcl-2, Bid, Bak, and Bax molecules was evaluated at onset of diagnosis, 24 h after symptom onset, and 6 months later in the nasopharyngeal cells of SARS-CoV-2-infected hospitalized patients and outpatients in comparison with healthy controls using the real-time PCR technique. At the onset of the study, the relative expression of p53, Bcl-2, Bid, Bak, and Bax significantly increased in the SARS-CoV-2-infected hospitalized patients and decreased after 6 months. The healthy controls showed potential positive correlations among the molecules, but the patients did not show these correlations. Since SARS-CoV-2 needs host cell survival, it appears that the virus induces the expression of Bcl-2 as an antiapoptotic molecule, and the host cells upregulate the proapoptotic molecules to neutralize the effects. Dysregulation of correlation expression of the molecules among the patients proved that SARS-CoV-2 affects the expression of the molecules involved in apoptosis. SARS-CoV-2 could be considered an important factor that regulates the expression of several molecules participating in cancer pathogenesis.

Metabolic Fingerprinting of Serum and Seminal Plasma of Testicular Cancer Patients Using Raman Spectroscopy: A Pilot Study.

Background: Testicular cancer (TC) is a relatively rare type of cancer in men. Early diagnosis of TC remains challenging. Metabolomics holds promise in offering valuable insights in this regard. In this study, a metabolic fingerprinting approach was employed to identify potential biomarkers in both serum and seminal plasma of TC patients. Methods: A total of 9 patients with testicular cancer and 10 controls were included in the study. The metabolic fingerprinting approach was utilized as a rapid diagnostic tool to analyze the metabolome in serum and seminal plasma of TC patients in comparison to fertile men. Raman spectroscopy was applied for the analysis of metabolites in these biological samples. Results: Principal component analysis (PCA) and functional group analysis showed that the differentiation between serum samples from healthy men and TC patients was not possible. However, when analyzing seminal plasma, a significant difference was found between the two groups (p<0.05). Functional group analysis of serum only showed an increase in tryptophan concentration ratio in TC patients as compared to healthy men (p=0.03). In contrast, in seminal plasma of TC patients, this increase was observed in all analyzed compounds, including phenylalanine, tyrosine, lipids, proteins, phenols (p<0.001). Conclusion: Our study highlights the potential of metabolic fingerprinting as a fast diagnostic tool for screening TC patients, with seminal plasma serving as a valuable biological sample. Furthermore, several potential biomarkers, particularly phenylalanine, were identified in seminal plasma. This research contributes to our understanding of TC pathogenesis and has the potential to pave the way for early detection and personalized treatment approaches.

Higher expression of SALL4-A isoform is correlated with worse outcomes and progression of the disease in subtype of testicular germ cell tumours.

BACKGROUND: The transcription factor SALL4 is associated with embryonic pluripotency and has proposed as a novel immunohistochemistry (IHC) marker for diagnosing germ cell tumours. SALL4 comprises three isoforms, and SALL4-A being the full-length isoform. Studying its isoforms could revolutionize testicular cancer prognosis and subtype differentiation. METHODS: The expression and clinical significance of isoform 'A' of SALL4 was evaluated in 124 testicular germ cell tumours (TGCTs) subtypes, adjacent 67 normal tissues and 22 benign tumours, using immunohistochemistry on tissue microarrays (TMA). RESULTS: A statistically significant higher expression of nuclear and cytoplasmic SALL4-A was detected in TGCTs histological subtypes and benign tumours compared to the normal tissues. Seminoma and yolk sac tumours had the highest nuclear and cytoplasmic expression of SALL4-A. A significant correlation was detected between the higher nuclear expression of SALL4-A and increased pT stages (P = 0.026) in seminomas. Whereas in embryonal carcinomas, cytoplasmic expression of SALL4-A was associated with the tumour recurrence (P = 0.04) and invasion of the epididymis (P = 0.011). CONCLUSIONS: SALL4-A isoform expression in the cytoplasm and nucleus of TGCTs may be associated with histological differentiation. In the seminoma subtype of TGCTs, higher expression of SALL4-A may be used as a predictive indicator of poorer outcomes and prognosis.

Clinical significance of CD166 and HER-2 in different types of gastric cancer

Introduction Cluster of differentiation 166 (CD166), a cancer stem cell (CSC) marker, and human epidermal growth factor receptor 2 (HER-2) are expressed in a diversity of malignancies and is associated with tumor progression. Although studies regarding the importance of CSC markers and HER-2 in gastric cancer (GC) have rapidly developed, their clinicopathological, prognosis, and diagnosis value still remain unsatisfying in GC. Therefore, the present study aims to investigate the clinical, prognostic, and diagnostic significance of CD166 and HER-2 in different histological types of GC. Materials and methods Bioinformatic analysis was applied to determine the clinical importance of CD166 and HER-2 expression based on their tissue localization in primary GC tumors and the normal adjacent samples. The expression patterns, clinical significance, prognosis, and diagnosis value of CD166 and HER-2 proteins in tissue microarrays (TMAs) of 206 GC samples, including Signet Ring Cell (SRC) and intestinal types and also 28 adjacent normal tissues were evaluated using immunohistochemistry (IHC). Results The results indicated that the expression of CD166 (membranous and cytoplasmic) and HER-2 were significantly up-regulated in tumor cells compared to adjacent normal tissues (P = 0.010, P < 0.001, and P = 0.011, respectively). A statistically significant association was detected between a high level of membranous expression of CD166 and lymphovascular invasion (P = 0.006); We also observed a statistically significant association between high cytoplasmic expression of CD166 protein and more invasion of the subserosa (P = 0.040) in the SRC type. In contrast, there was no correlation between the expression of HER-2 and clinicopathologic characteristics. Both CD166 and HER-2 showed reasonable accuracy and high specificity as diagnostic markers (AU)

Novel neutralizing SARS-CoV-2-specific mAbs offer detection of RBD linear epitopes.

BACKGROUND: To stop the spread of the COVID-19 disease, it is crucial to create molecular tools to investigate and diagnose COVID-19. Current efforts focus on developing specific neutralizing monoclonal antibodies (NmAbs) elicited against the receptor-binding domain (RBD). METHODS: In the present study, recombinant RBD (rRBD) protein was produced in E. coli, followed by immunizing mice with purified rRBD. ELISA was applied to screen the hybridomas for positive reactivity with rRBD protein. The linear and conformational epitopes of the mAbs were subsequently identified using western blot. Finally, the reactivity, affinity, and neutralization activity of the purified mAbs were evaluated using ELISA. RESULTS: All mAbs exhibited similar reactivity trends towards both eukaryotic RBD and prokaryotic rRBD in ELISA. Among them, 2E7-D2 and 2B4-G8 mAbs demonstrated higher reactivity than other mAbs. Additionally, in western blot assays, these two mAbs could detect reducing and non-reducing rRBD, indicating recognition of linear epitopes. Notably, five mAbs effectively blocked rRBD- angiotensin-converting enzyme 2 (ACE2) interaction, while two high-affinity mAbs exhibited potent neutralizing activity against eukaryotic RBD. CONCLUSION: In the current study, we generated and characterized new RBD-specific mAbs using the hybridoma technique that recognized linear and conformational epitopes in RBD with neutralization potency. Our mAbs are novel candidates for diagnosing and treating SARS-CoV-2.

Clinical significance of CD166 and HER-2 in different types of gastric cancer.

INTRODUCTION: Cluster of differentiation 166 (CD166), a cancer stem cell (CSC) marker, and human epidermal growth factor receptor 2 (HER-2) are expressed in a diversity of malignancies and is associated with tumor progression. Although studies regarding the importance of CSC markers and HER-2 in gastric cancer (GC) have rapidly developed, their clinicopathological, prognosis, and diagnosis value still remain unsatisfying in GC. Therefore, the present study aims to investigate the clinical, prognostic, and diagnostic significance of CD166 and HER-2 in different histological types of GC. MATERIALS AND METHODS: Bioinformatic analysis was applied to determine the clinical importance of CD166 and HER-2 expression based on their tissue localization in primary GC tumors and the normal adjacent samples. The expression patterns, clinical significance, prognosis, and diagnosis value of CD166 and HER-2 proteins in tissue microarrays (TMAs) of 206 GC samples, including Signet Ring Cell (SRC) and intestinal types and also 28 adjacent normal tissues were evaluated using immunohistochemistry (IHC). RESULTS: The results indicated that the expression of CD166 (membranous and cytoplasmic) and HER-2 were significantly up-regulated in tumor cells compared to adjacent normal tissues (P = 0.010, P < 0.001, and P = 0.011, respectively). A statistically significant association was detected between a high level of membranous expression of CD166 and lymphovascular invasion (P = 0.006); We also observed a statistically significant association between high cytoplasmic expression of CD166 protein and more invasion of the subserosa (P = 0.040) in the SRC type. In contrast, there was no correlation between the expression of HER-2 and clinicopathologic characteristics. Both CD166 and HER-2 showed reasonable accuracy and high specificity as diagnostic markers. CONCLUSION: Our results confirmed that increased membranous and cytoplasmic expression of CD166 showed clinical significance in the SRC type and is associated with the progression of the disease and more aggressive tumor behaviors. These findings can be used to assist in designating subgroups of patients that require different follow-up strategies, and also, they might be utilized as the prognostic or diagnostic biomarkers in these types of GC for prospective clinical application.

Clinico-Pathological and Prognostic Significance of a Combination of Tumor Biomarkers in Iranian Patients With Breast Cancer.

PURPOSE: Breast cancer is one of the most common cancers in the world. It is a multifaceted malignancy with different histopathological and biological features. Molecular biomarkers play an essential role in accurate diagnosis, classification, prognosis, prediction of treatment response, and cancer surveillance. This study investigated the clinico-pathological and prognostic significance of HER3 and ROR1 in breast cancer samples. METHODS: Tissue microarrays (TMA) were constructed using tissue blocks of 444 Iranian breast cancer patients diagnosed with breast cancer. Overall survival (OS) and disease-free survival (DFS) were assessed after 5 years follow-up. TMA slides were stained with monoclonal antibodies against ROR1, HER3, ER, PR, Ki67, P53, HER2 and CK5/6 using IHC and correlation between the investigated tumor markers and the clinico-pathological parameters of patients were analyzed. RESULTS: Our results showed a significant correlation between ROR1 and ER, PR, HER3, and CK5/6 expression. Additionally, there was a significant correlation between HER3 and ER, PR, HER2, and Ki67 expression. Ki67 was also correlated with HER2 and P53 expression. HER3 expression was significantly correlated with tumor stage, lymph node metastasis, perineural invasion, and multifocal tumors. Furthermore, ROR1 expression was significantly associated with tumor metastasis, lympho-vascular invasion, and perineural invasion. While HER2-HER3 coexpression was significantly associated with poor OS, HER3-ROR1 coexpression was associated with lymph node invasion, lymph node metastasis, and distant metastasis. CONCLUSION: ROR1 and HER3 displayed significant association with different clinic-pathological features and in addition to the other tumor biomarkers could be considered as diagnostic and prognostic biomarkers in breast cancer patients.

The Association Between Higher Expression of Talin-1 and the Reduced Survival Rate in Ovarian Serous Carcinoma Patients.

Background & Objective: Talin-1 is a constituent of the multiprotein adhesion complexes that play main role in the formation of tumors and migration in different types of malignancies. The present study aimed to assess expression and prognostic significance of the talin-1 protein in ovarian serous carcinoma (OSC) patients. Methods: The expression of talin-1 in mRNA and its protein levels were investigated for ovarian cancer (OC) by using bioinformatics tools, including Gene Expression Profiling Interactive Analysis 2 (GEPIA2), Gene Expression Database of Normal and Tumor Tissue 2 (GENT2), and The University of ALabama at Birmingham CANcer data analysis Portal (UALCAN) databases. Thereafter, immunohistochemical (IHC) staining was used to study the expression patterns of the talin-1 protein using 46 paraffin-embedded OSC tissue specimens, 25 benign tumors, and 20 normal tissues, which were assembled in tissue microarrays (TMAs). We also assessed the potential association between the expression of the talin-1 protein, various clinicopathological parameters, and survival outcomes. Results: Our IHC examination for talin-1 was significantly overexpressed in OSC tissues compared to benign tumors and normal tissues. The Kaplan-Meier survival analysis has also indicated statistically significant differences in terms of disease-specific survival (DSS) and progression-free survival (PFS) between the patients with high and low expression levels of talin-1, respectively. Conclusion: The talin-1 protein was overexpressed in OSC tissues, and a high expression level of talin-1 was found to be significantly associated with tumor aggressiveness and poorer DSS or PFS. Therefore, talin-1 may serve as a molecular marker of cancer progression and a novel prognostic biomarker in these patients.

Nuclear overexpression of DNA damage-inducible transcript 4 (DDIT4) is associated with aggressive tumor behavior in patients with pancreatic tumors.

DNA damage-inducible transcript 4 (DDIT4) is induced in various cellular stress conditions. Several studies showed that the dysregulation of DDIT4 is involved in different malignancies with paradoxical expressions and roles. Therefore, this study investigated the clinical significance, prognostic, and diagnostic value of DDIT4 in different types of pancreatic tumors (PT). The expression of DDIT4 and long non-coding RNA (TPTEP1) in mRNA level was examined in 27 fresh PT samples using Real-time quantitative PCR (RT-qPCR). Moreover, 200 formalin-fixed paraffin-embedded PT tissues, as well as 27 adjacent normal tissues, were collected to evaluate the clinical significance, prognostic, and diagnosis value of DDIT4 expression by immunohistochemistry (IHC) on tissue microarrays (TMA) slides. The results of RT-qPCR showed that the expression of DDIT4 in tumor samples was higher than in normal samples which was associated with high tumor grade (P = 0.015) and lymphovascular invasion (P = 0.048). Similar to this, IHC findings for nucleus, cytoplasm, and membrane localization showed higher expression of DDIT4 protein in PT samples rather than in nearby normal tissues. A statistically significant association was detected between a high level of nuclear expression of DDIT4 protein, and lymphovascular invasion (P = 0.025), as well as advanced TNM stage (P = 0.034) pancreatic ductal adenocarcinoma (PDAC) and in pancreatic neuroendocrine tumor (PNET), respectively. In contrast, a low level of membranous expression of DDIT4 protein showed a significant association with advanced histological grade (P = 0.011), margin involvement (P = 0.007), perineural invasion (P = 0.023), as well as lymphovascular invasion (P = 0.005) in PDAC. No significant association was found between survival outcomes and expression of DDIT4 in both types. It was found that DDIT4 has rational accuracy and high sensitivity as a diagnostic marker. Our results revealed a paradoxical role of DDIT4 expression protein based on the site of nuclear and membranous expression. The findings of this research indicated that there is a correlation between elevated nuclear expression of DDIT4 and the advancement and progression of disease in patients with PT. Conversely, high membranous expression of DDIT4 was associated with less aggressive tumor behavior in patients with PDAC. However, further studies into the prognostic value and biological function of DDIT4 are needed in future studies.

Engineering chimeric autoantibody receptor T cells for targeted B cell depletion in multiple sclerosis model: An in-vitro study.

Background: Recent evidence suggests that B cells and autoantibodies have a substantial role in the pathogenesis of Multiple sclerosis. T cells could be engineered to express chimeric autoantibody receptors (CAARs), which have an epitope of autoantigens in their extracellular domain acting as bait for trapping autoreactive B cells. This study aims to assess the function of designed CAAR T cells against B cell clones reactive to the myelin basic protein (MBP) autoantigen. Methods: T cells were transduced to express a CAAR consisting of MBP as the extracellular domain. experimental autoimmune encephalomyelitis (EAE) was induced by injecting MBP into mice. The cytotoxicity, proliferation, and cytokine production of the MBP-CAAR T cells were investigated in co-culture with B cells. Results: MBP-CAAR T cells showed higher cytotoxic activity against autoreactive B cells in all effector-to-target ratios compared to Mock T cell (empty vector-transduced T cell) and Un-T cells (un-transduced T cell). In co-cultures containing CAAR T cells, there was more proliferation and inflammatory cytokine release as compared to Un-T and Mock T cell groups. Conclusion: Based on these findings, CAAR T cells are promising for curing or modulating autoimmunity and can be served as a new approach for clone-specific B cell depletion therapy in multiple sclerosis.

P53, CK20, and FGFR3 Overexpression is Associated with the Characteristics of Urothelial Cell Carcinoma of the Bladder

OBJECTIVES: The aim of this study was to investigate the association between the overexpression of tumor protein (P53), cytokeratin 20 (CK20), fibroblast growth factor receptor 3 (FGFR3), biomarkers and the grading, prognosis, heterogeneity, and relapse tendency of urothelial cell carcinomas (UCCs) of the bladder. METHODS: A cross-sectional study was conducted using 413 samples of Iranian patients diagnosed with UCC of the bladder. The tissue microarray technique was used to evaluate the patterns of tumor tissue. Two pathologists scored tissue staining using a semi-quantitative scoring system. RESULTS: The results showed that P53 was a predictor of a high-grade pattern (the area under the curve (AUC)=0.620) with a best cut-off value of 95.0 using the receiver operating characteristic (ROC) curve. CK20 was another predictor of a high-grade pattern (AUC=0.745) with a best cut-off value of 15. However, the overexpression of both biomarkers was not associated with a heterogeneous pattern and could not predict tumor-associated death or relapse. The heterogeneous (odds ratio (OR)=4.535, p-value=0.001) and non-papillary (OR= 6.363, p-value= 0.001) patterns were effective predictors of tumor recurrence among all baseline variables, including patient and tumor characteristics. FGFR3 was positive in all specimens and was not a valuable biomarker for differentiating patterns. None of the variables predicted tumor prognosis. CONCLUSION: The study findings indicate that the intensity and percentage of cell staining for P53 and CK20 in the UCC of the bladder can aid in differentiating the grading patterns. The tendency of tumor relapse can be predicted by demonstrating heterogeneous and non-papillary patterns.

Quantitative measurement of CA 15-3 cancer biomarker using an electrochemical aptasensor based on the electrodeposition of Au thin film on cauliflower-like rGO-MoS2 nanocomposite.

The present research was conducted to design and construct an electrochemical aptasensor for evaluating carbohydrate antigen 15-3 (CA15-3) as a biomarker for breast cancer. The aptasensor has been fabricated by a gold thin film (AuTF) electrodeposited on a cauliflower-like reduced graphene oxide-molybdenum sulfide nanocomposite (rGO-MoS2). The modified electrode's surface was used to immobilize the thiolated aptamer, which was subsequently treated with CA 15-3 antigen. The aptasensor fabrication process was assessed using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). This research also applied EIS to the quantitative measurement of CA 15-3 antigen by the proposed aptasensor. The interfacial charge transfer resistance (Rct) alteration before and after incubation of CA 15-3 by the immobilized aptamer was considered a signal for the quantitative measurement of CA 15-3. A linear concentration ranging from 5.0 to 200.0 U mL-1 with a detection limit of 3.0 × 10-1 U mL-1 was obtained for CA 15-3 using the EIS method. This designed aptasensor indicates satisfactory repeatability and stability, good selectivity, and high sensitivity. Moreover, clinical samples were assayed by the prepared aptasensor and compared with the ELISA method, yielding acceptable results. The recovery and relative standard deviation (RSD) of CA 15-3 in human serum samples were in the range 95.0 to 107.0% and 3.5 to 7.5%, respectively.

COVID-19 pandemic impact on screening and diagnosis of prostate cancer: a systematic review.

INTRODUCTION: The healthcare level has been greatly affected by the COVID-19 pandemic compared with before the outbreak. This study aimed to review the impact of COVID-19 on the screening and diagnosis of prostate cancer (PCa). METHOD: The current study was designed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020. The keywords used to perform the search strategy were COVID-19 and prostate neoplasms. The four primary electronic databases comprising PubMed/MEDLINE, Web of Science, Scopus and Embase were searched until 1 September 2022. After screening and selecting studies through the EndNote software, data were extracted from each included study by two independent authors. All studies were evaluated according to Newcastle-Ottawa Scale quality assessment tool. RESULTS: As a result, 40 studies were included, categorised into two subjects. The majority of studies indicated a significant decrease in screening prostate-specific antibody tests during the COVID-19 pandemic compared with the pre-pandemic period, leading to delays in cancer diagnosis. The decrease in the number of diagnosed cases with low/intermediate stages to some extent was more than those with advanced stages. The PCa screening and diagnosis reduction ranged from nearly 0% to 78% and from 4.1% to 71.7%, respectively. CONCLUSION: Our findings showed that during the COVID-19 lockdown, delays in PCa screening tests and diagnoses led to the negative health effects on patients with PCa. Thus, it is highly recommended performing regular cancer screening to reduce the impact of the COVID-19 lockdown. PROSPERO REGISTRATION NUMBER: CRD42021291656.

Heterotypic tumor spheroids: a platform for nanomedicine evaluation.

Nanomedicine has emerged as a promising therapeutic approach, but its translation to the clinic has been hindered by the lack of cellular models to anticipate how tumor cells will respond to therapy. Three-dimensional (3D) cell culture models are thought to more accurately recapitulate key features of primary tumors than two-dimensional (2D) cultures. Heterotypic 3D tumor spheroids, composed of multiple cell types, have become more popular than homotypic spheroids, which consist of a single cell type, as a superior model for mimicking in vivo tumor heterogeneity and physiology. The stromal interactions demonstrated in heterotypic 3D tumor spheroids can affect various aspects, including response to therapy, cancer progression, nanomedicine penetration, and drug resistance. Accordingly, to design more effective anticancer nanomedicinal therapeutics, not only tumor cells but also stromal cells (e.g., fibroblasts and immune cells) should be considered to create a more physiologically relevant in vivo microenvironment. This review aims to demonstrate current knowledge of heterotypic 3D tumor spheroids in cancer research, to illustrate current advances in utilizing these tumor models as a novel and versatile platform for in vitro evaluation of nanomedicine-based therapeutics in cancer research, and to discuss challenges, guidelines, and future directions in this field.

Tumor matrix stiffness provides fertile soil for cancer stem cells.

Matrix stiffness is a mechanical characteristic of the extracellular matrix (ECM) that increases from the tumor core to the tumor periphery in a gradient pattern in a variety of solid tumors and can promote proliferation, invasion, metastasis, drug resistance, and recurrence. Cancer stem cells (CSCs) are a rare subpopulation of tumor cells with self-renewal, asymmetric cell division, and differentiation capabilities. CSCs are thought to be responsible for metastasis, tumor recurrence, chemotherapy resistance, and consequently poor clinical outcomes. Evidence suggests that matrix stiffness can activate receptors and mechanosensor/mechanoregulator proteins such as integrin, FAK, and YAP, modulating the characteristics of tumor cells as well as CSCs through different molecular signaling pathways. A deeper understanding of the effect of matrix stiffness on CSCs characteristics could lead to development of innovative cancer therapies. In this review, we discuss how the stiffness of the ECM is sensed by the cells and how the cells respond to this environmental change as well as the effect of matrix stiffness on CSCs characteristics and also the key malignant processes such as proliferation and EMT. Then, we specifically focus on how increased matrix stiffness affects CSCs in breast, lung, liver, pancreatic, and colorectal cancers. We also discuss how the molecules responsible for increased matrix stiffness and the signaling pathways activated by the enhanced stiffness can be manipulated as a therapeutic strategy for cancer.

Novel Monoclonal Antibodies Specific for Human Ki67 and P53 Tumor Markers in Breast Cancer Tissue Samples.

Background: Ki67 and P53 are important diagnostic and prognostic biomarkers expressed in several cancers. The current standard method for evaluating Ki67 and P53 in cancer tissues is immunohistochemistry (IHC), and having highly sensitive monoclonal antibodies against these biomarkers is necessary for an accurate diagnosis in the IHC test. Objective: To generate and characterize novel monoclonal antibodies (mAbs) against human Ki67 and P53 antigens for IHC purposes. Methods: Ki67 and P53-specific mAbs were produced by the hybridoma method and screened by enzyme-linked immunosorbent assay (ELISA) and IHC techniques. Selected mAbs were characterized using Western blot and flow cytometry, and their affinities and isotypes were determined by ELISA. Moreover, using the IHC technique in 200 breast cancer tissue samples, we assessed the specificity, sensitivity, and accuracy of the produced mAbs. Results: Two anti-Ki67 (2C2 and 2H1) and three anti-P53 mAbs (2A6, 2G4, and 1G10) showed strong reactivity to their target antigens in IHC. The selected mAbs were also able to recognize their targets by flow cytometry as well as Western blotting using human tumor cell lines expressing these antigens. The specificity, sensitivity, and accuracy calculated for clone 2H1 were 94.2%, 99.0%, and 96.6%, and for clone 2A6 were 97.3%, 98.1%, and 97.5%, respectively. Using these two monoclonal antibodies, we found a significant correlation between Ki67 and P53 overexpression and lymph node metastasis in patients with breast cancer. Conclusion: The present study showed that the novel anti-Ki67 and anti-P53 mAbs could recognize their respective antigens with high specificity and sensitivity and therefore can be used in prognostic studies.