The prognostic role of tissue TLR2 and TLR4 in colorectal cancer

Prediction of the survival status and tumor microenvironment in colorectal cancer through genotyping analysis based on toll-like receptors

BACKGROUND

Colorectal cancer (CRC) ranks third in both the incidence and mortality rates among male and female cancers, and it is the leading digestive system cancer. Due to the inter- and intratumor heterogeneity of cancer, the TNM system is insufficient for predicting prognosis, necessitating the use of molecular biomarkers for prognostic prediction. Toll-like receptors (TLRs) have been associated with CRC survival rates. This study focused on the investigation of the role and potential value of TLRs in CRC genotyping to aid in immunotherapy for CRC patients.

METHODS

Differential gene expression analysis was performed on CRC transcriptomic data from The Cancer Genome Atlas database. TLRs were referred from the literature, and their intersection with differentially expressed genes (DEGs) in CRC yielded TLR-DEGs. The expression patterns of TLR-DEGs were predicted using the STRING website, and copy number variations of TLR-DEGs were analyzed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted on TLR-DEGs. ConsensusClusterPlus R package was used for clustering CRC patients, and ESTIMATE and GSEAbase were employed to analyze immune characteristics of different subtypes. Immune phenotyping scores and tumor immune dysfunction and exclusion scores were evaluated. DEGs of different subtypes were analyzed, followed by GO and KEGG enrichment analyses, the protein-protein interaction (PPI) network analysis, and further selection of hub genes. The sensitivity of drugs was assessed using the identified hub genes.

RESULTS

We identified 37 TLR-DEGs, and the PPI analysis revealed their coexpression, although they were distributed on different chromosomes. Enrichment analyses indicated that the 37 TLR-DEGs were linked to cancer cell immune response. Based on these TLR-DEGs, CRC patients were classified into three subtypes. Cluster2 exhibited lower survival rates and higher immune infiltration levels and predicted poorer response to immune checkpoint inhibitor therapy. The intersection of DEGs from cluster2 and cluster1 with DEGs from cluster2 and cluster3 yielded a set of 426 commonly shared DEGs. Enrichment analyses revealed that these shared DEGs might regulate immune cell viability. Eight common hub genes for different subtypes were further identified to predict drug-related correlations.

CONCLUSION

The developed TLR genotyping was used to predict the survival status and tumor microenvironment of CRC, providing a foundation for understanding the molecular mechanisms of TLR signaling and deepening its clinical significance.

Clinicopathological Significance and Prognostic Role of High Mobility Group Box 1 (HMGB1), Toll-Like Receptor (TLR) 2 and TLR4 in Breast Cancer

High-mobility group box 1 (HMGB1) functions as damage-associated molecular pattern (DAMPs), released into extracellular space during cellular stress. Extracellular HMGB1 act as signal molecules through Toll-like receptor (TLR) 2 or TLR4, exerting diverse functions in both normal cells and malignant cells including breast cancer. However, their comprehensive examination in breast cancer tissues is lacking. Thus, we immunolocalized them in 112 breast cancer tissues, correlating their immunoreactivity with clinicopathological parameters and clinical outcomes to clarify their significance in breast cancer. We demonstrated that nuclear HMGB1 immunoreactivity was correlated with tumor progression and longer disease-free survival. In contrast, TLR2 immunoreactivity was correlated with increased cell proliferation and shorter disease-free survival, dependent on cytoplasmic HMGB1 immunoreactivity. Additionally, TLR4 immunoreactivity correlated with chemoresistance, regardless of cytoplasmic HMGB1 immunoreactivity. It was therefore considered that TLR2 collaboratively contributed to breast cancer progression with HMGB1-DAMPs to become a worse prognostic factor. Meanwhile, TLR4 served as a worse prognostic factor associated with chemoresistance, irrespective of HMGB1.

Prognostic and clinicopathological significance of TLR4 expression in patients with breast cancer: a meta-analysis

Background

The prognostic value of Toll-like receptor 4 (TLR4) in breast cancer remains to be determined. Therefore, this paper aims to conduct a meta-analysis to assess the correlation between TLR4 and clinicopathological indicators as well as survival outcomes in breast cancer.

Method

Related literature retrieved from Embase, PubMed, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI) and China Wanfang. The search deadline is April 12, 2023. The outcome measures employed in the study comprised hazard ratio (HR), odds ratio (OR), and 95% confidence interval (CI) as effective indices. The data analysis was conducted using Stata 17.0 software.

Results

High TLR4 expression was associated with lymph node metastasis (OR=2.077, 95%CI=1.160-3.717, P= 0.014), tumor size (≥2 cm) (OR=2.194, 95%CI= 1.398-3.445, P= 0.001), PR expression (OR = 0.700, 95% CI = 0.505-0.971, P= 0.033), and clinical stage (OR = 3.578, 95%CI= 3.578-5.817, P<0.05), but not with histological grade (95%CI= 0.976-1.735, P= 0.072), ER expression (OR = 1.125, 95% CI = 0.492-2.571,P= 0.781), and HER-2 status (OR = 1.241, 95% CI = 0.733-2.101, P = 0.422). In addition, TLR4 overexpression was an independent prognostic indicator of DFS (HR= 1.480, 95%CI= 1.028- 2.130, p= 0.035) in breast cancer patients, but not related to OS(HR=1.730, 95%CI= 0.979-3.057, P= 0.059).

Conclusions

From our main analysis results, high TLR4 expression is associated with lymph node metastasis, larger tumor size (≥2 cm), later clinical stage, negative PR expression and shorter DFS, suggesting poor prognosis in breast cancer patients.

TLR4, IgA and EpCAM Expression in Colorectal Cancer and Their Possible Association with Microbiota as a Pathogenic Factor; An Immunohistochemical and Genetic Study

BACKGROUND

The pathogenesis of inflammatory bowel disease (IBD) and colorectal cancer (CRC) is thought to be related to immune response against gut microbiota. TLR4, IgA, and EpCAM have a role in intestinal local immune response and their altered expression related to both IBD and CRC. Lipopolysaccharide (LPS) is the main activator of TLR4. The objective of this study is to evaluate the possible role of intestinal microbiota in the pathogenesis of IBD and CRC through expression of TLR4, IgA and EpCAM.

METHODS

One hundred five cases were divided into (Group 1/ Control: 10 sections of normal colonic mucosa, Group 2/CRC: 51 cases, Group 3/IBD: 44 cases). Immunohistochemistry for TLR4, IgA, and EpCAM was done. LPS was assessed in all groups. TLR4 gene and protein expression were assessed in colorectal cancer cell line by RT-PCR and immunocytochemistry.

RESULTS

There was a significant correlation between TLR4 and tumor grade (P value 0.003 and 0.01 respectively). A significant correlation was found between IgA expression and T stage (P value 0.02) and between EpCAM expression and histologic type (P value 0.02). In comparison of CRC patients to controls; there was a statistically significant different expression of TLR4 positivity, IgA positivity and EpCAM (P value <0.001, 0.004, <0.001 respectively). Patients with CRC were compared to colitis patients and there was a statistically significant different expression of IgA positivity and EpCAM expression (P value <0.001). There was significant higher expression of TLR4 in CRC cell line than the fibroblast by both PCR and immunocytochemistry (P-value: 0.003 and 0.024 respectively). LPS level in CRC patients was significantly higher than the control and IBD groups (P values <0.001 and <0.001 respectively).

CONCLUSION

TLR4, IgA, EpCAM expression in both CRC and IBD might be related to the pathogenic role of microbiota and could represent potential prevention modalities and therapeutic targets.

Toll-like receptor-guided therapeutic intervention of human cancers: molecular and immunological perspectives

Toll-like receptors (TLRs) serve as the body's first line of defense, recognizing both pathogen-expressed molecules and host-derived molecules released from damaged or dying cells. The wide distribution of different cell types, ranging from epithelial to immune cells, highlights the crucial roles of TLRs in linking innate and adaptive immunity. Upon stimulation, TLRs binding mediates the expression of several adapter proteins and downstream kinases, that lead to the induction of several other signaling molecules such as key pro-inflammatory mediators. Indeed, extraordinary progress in immunobiological research has suggested that TLRs could represent promising targets for the therapeutic intervention of inflammation-associated diseases, autoimmune diseases, microbial infections as well as human cancers. So far, for the prevention and possible treatment of inflammatory diseases, various TLR antagonists/inhibitors have shown to be efficacious at several stages from pre-clinical evaluation to clinical trials. Therefore, the fascinating role of TLRs in modulating the human immune responses at innate as well as adaptive levels directed the scientists to opt for these immune sensor proteins as suitable targets for developing chemotherapeutics and immunotherapeutics against cancer. Hitherto, several TLR-targeting small molecules (e.g., Pam3CSK4, Poly (I:C), Poly (A:U)), chemical compounds, phytocompounds (e.g., Curcumin), peptides, and antibodies have been found to confer protection against several types of cancers. However, administration of inappropriate doses of such TLR-modulating therapeutics or a wrong infusion administration is reported to induce detrimental outcomes. This review summarizes the current findings on the molecular and structural biology of TLRs and gives an overview of the potency and promises of TLR-directed therapeutic strategies against cancers by discussing the findings from established and pipeline discoveries.

An ICD-Associated DAMP Gene signature predicts survival and immunotherapy response of patients with lung adenocarcinoma

BACKGROUND

While some lung adenocarcinoma (LUAD) patients benefit long-term from treatment with immune checkpoint inhibitors, the sad reality is that a considerable proportion of patients do not. The classification of the LUAD tumor microenvironment (TME) can be used to conceptually comprehend primary resistance mechanisms. In addition, the most recent research demonstrates that the release of damage-associated molecular pattern (DAMP) in TME by immunogenic cell death (ICD) may contribute to the adaptive immune response. Currently, however, there is no such comprehensive research on this topic in LUAD patients. Therefore, we set out to investigate how to reverse the poor infiltration characteristics of immune cells and boost antitumor immunity by identifying DAMP model.

METHODS

In this study, ICD-related DAMP genes were selected to investigate their effects on the prognosis of LUAD. To create a risk signature using the TCGA-LUAD cohort, the univariate COX regression and the least absolute shrinkage and selection operator regression were carried out, and the results were verified in a GEO dataset. Subsequently, the multivariate COX regression was applied to establish a prognostic nomogram. And the ESTIMATE and ssGSEA algorithms were utilized to analyze immune activity and the TIDE algorithm was for responsiveness to immunotherapy. Moreover, clinical tissue samples were used to verify the differential expression of 9 DAMP genes in the signature.

RESULTS

We identified two distinct DAMP molecular subtypes, and there are remarkable differences in survival probability between the two subtypes, and patients with higher levels of DAMP-related genes are "hot tumors" with increased immune activity. In addition, 9 DAMP genes were selected as prognostic signature genes, and clinical outcomes and immunotherapy response were better for participants in the low-risk group. Importantly, according to the area under the curve (AUC) value in evaluating the efficacy of immunotherapy, this signature is superior to existing predictors, such as PD-L1 and TIDE.

CONCLUSIONS

Our study suggests ICD plays an important part in modeling the TME of LUAD patients. And this signature could be utilized as a reliable predictor to estimate clinical outcomes and predict immunotherapy efficacy among LUAD patients.

TLR4 inhibited autophagy by modulating PI3K/AKT/mTOR signaling pathway in Gastric cancer cell lines

Toll-like receptors (TLRs) are pattern recognition receptors found on both immune and cancerous cells. Gastric cancer (GC) cells/tissues have been shown to exhibit elevated levels of TLR4. Here, we examined the role of TLR4 on autophagy and proliferation in GC cells. Real-time quantitative polymerase chain reaction (RT-qPCR) and western blot (WB) were used to determine TLR4 levels at different stages of GC cells/tissues as well as the levels of autophagy-related proteins (ARPs) and determine the underlying signaling mechanism. Proliferation was assessed via the CCK-8 assay. The protein and mRNA levels of ARPs were elucidated, followed by estimating the involved signaling pathways. Our results demonstrated that the modulation of the PI3K/AKT/mTOR pathway resulted from autophagy inhibition/induction, which was induced by the overexpression and knockdown of TLR4. Thus, TLR4 played a vital role in GC progression.

Could Toll-like Receptor 2 Serve as Biomarker to Detect Advanced Gastric Cancer?

Gastric cancer is one of the five most common types of cancer worldwide. Due to the heterogeneous course and the involvement of many risk factors, its treatment and diagnosis is an important challenge for modern medicine. Recent studies have emphasized the i role of Toll-like receptors (TLRs) expressed on selected cells of the immune system in the pathogenesis of gastric cancer. The aim of this study was to determine the prevalence of TLR2 on T lymphocytes, B lymphocytes, monocytes, and dendritic cells in patients diagnosed with gastric cancer, with particular emphasis on the stage of the disease. Based on the obtained results, we have shown that patients with gastric cancer are characterized by a higher percentage of all tested populations of peripheral blood immune cells expressing TLR2 in relation to patients from the control group. Moreover, a detailed analysis of the collected results showed a significant link between TLR2 and the stage of the disease.

Unraveling the Complex Interconnection between Specific Inflammatory Signaling Pathways and Mechanisms Involved in HIV-Associated Colorectal Oncogenesis

The advancement of HIV treatment has led to increased life expectancy. However, people living with HIV (PLWH) are at a higher risk of developing colorectal cancers. Chronic inflammation has a key role in oncogenesis, affecting the initiation, promotion, transformation, and advancement of the disease. PLWH are prone to opportunistic infections that trigger inflammation. It has been documented that 15-20% of cancers are triggered by infections, and this percentage is expected to be increased in HIV co-infections. The incidence of parasitic infections such as helminths, with Ascariasis being the most common, is higher in HIV-infected individuals. Cancer cells and opportunistic infections drive a cascade of inflammatory responses which assist in evading immune surveillance, making them survive longer in the affected individuals. Their survival leads to a chronic inflammatory state which further increases the probability of oncogenesis. This review discusses the key inflammatory signaling pathways involved in disease pathogenesis in HIV-positive patients with colorectal cancers. The possibility of the involvement of co-infections in the advancement of the disease, along with highlights on signaling mechanisms that can potentially be utilized as therapeutic strategies to prevent oncogenesis or halt cancer progression, are addressed.

High tissue expression of TLRs combined with high density of tumor infiltrating lymphocytes predicts a better prognosis in colorectal cancer patients

BACKGROUND

Colorectal cancer causes 935,000 cancer deaths yearly. High local immune cell infiltration serves as a positive prognostic factor in CRC. Toll-like receptors (TLRs) induce innate immune responses and lead to adaptive immune system activation. TLRs play protumorigenic and antitumorigenic roles. We aimed to explore the relationship between TLR immunoexpressions and the infiltration densities of T-lymphocytes in CRC.

METHODS

Immunohistochemical TLR2, TLR4, TLR5, and TLR7 positivity and the density of CD3- and CD8-positive cells in tumoral and stromal tissue were evaluated from the tissue microarray slides of 549 consecutive CRC surgical patients treated at Helsinki University Hospital, Finland, between 1998 and 2005. We calculated the associations and correlations using Pearson's chi-square and Spearman's correlation tests, generating survival curves using the Kaplan-Meier method.

RESULTS

Positive intratumoral CD3 and CD8 densities associated with a high TLR2 expression (p < 0.001 and p = 0.001, respectively) and a high TLR4 expression (p = 0.013 and p = 0.025). A low TLR5 immunoexpression associated with negative intratumoral CD3 (p = 0.001) and CD8 (p = 0.011) and a low stromal CD3 (p = 0.001). No association or correlation emerged between TLR7 immunoexpression and CD3 or CD8 cell density. A low CD3-CD8 tumor-stroma index indicated a worse prognosis among all TLR subgroups, except the TLR7-negative subgroup.

CONCLUSIONS

We detected significant associations and correlations between high tissue TLR2, TLR4, and TLR5 immunoexpressions and high densities of CD3- and CD8-positive cells. Combining these markers may improve the prognostic evaluation of CRC patients.

Structural insight and analysis of TLR4 interactions with IAXO-102, TAK-242 and SN-38: an in silico approach

Introduction

Toll-like receptor 4 (TLR4) has attracted interest due to its role in chemotherapy-induced gastrointestinal inflammation. This structural study aimed to provide in silico rational of the recognition and potential binding of TLR4 ligands IAXO-102, TAK-242, and SN-38 (the toxic metabolite of the chemotherapeutic irinotecan hydrochloride), which could contribute to rationale development of therapeutic anti-inflammation drugs targeting TLR4 in the gastrointestinal tract.

Methods

In silico docking was performed between the human TLR4-MD-2 complex and ligands (IAXO-102, TAK-242, SN-38) using Autodock Vina, setting the docking grids to cover either the upper or the lower bound of TLR4. The conformation having the lowest binding energy value (kcal/mol) was processed for post-hoc analysis of the best-fit model. Hydrogen bonding was calculated by using ChimeraX.

Results

Binding energies of IAXO-102, TAK-242 and SN-38 at the upper bound of TLR4-MD-2 ranged between - 3.8 and - 3.1, - 6.9 and - 6.3, and - 9.0 and - 7.0, respectively. Binding energies of IAXO-102, TAK-242 and SN-38 at the lower bound ranged between - 3.9 and - 3.5, - 6.5 and - 5.8, and - 8.2 and - 6.8, respectively. Hydrogen bonding at the upper bound of TLR4/MD-2 with IAXO-102, TAK-242 and SN-38 was to aspartic acid 70, cysteine 133 and serine 120, respectively. Hydrogen bonding at the lower bound of TLR4-MD-2 with IAXO-102, TAK-242 and SN-38 was to serine 528, glycine 480 and glutamine 510, respectively.

Conclusion

The in silico rational presented here supports further investigation of the binding activity of IAXO-102 and TAK-242 for their potential application in the prevention of gastrointestinal inflammation caused by SN-38.

Activation of angiotensin-converting enzyme 2 ameliorates metabolic syndrome-induced renal damage in rats by renal TLR4 and nuclear transcription factor κB downregulation

BACKGROUND

Metabolic syndrome (MetS) is an independent risk factor for chronic kidney disease (CKD) through many mechanisms, including activation of the renin-angiotensin system. The deleterious effects of angiotensin II (Ang II) can be counterbalanced by angiotensin-converting enzyme 2 (ACE2). Diminazene aceturate (DIZE), an anti-trypanosomal drug, can activate ACE2.

OBJECTIVE

This study aimed to investigate the possible reno-protective effects of DIZE in MetS rats with elucidation of related mechanisms.

MATERIALS AND METHODS

Thirty adult male Wistar albino rats were divided equally into control, MetS, and MetS + DIZE groups. Body weight, systolic blood pressure (SBP), and urinary albumin levels were measured. Serum levels of fasting blood glucose (FBG), insulin, uric acid, lipid profile, urea, and creatinine were measured. Homeostasis Model Assessment Index (HOMA-IR) was estimated. Subsequently, renal levels of ACE2, Ang II, malondialdehyde (MDA), reduced glutathione (GSH), and tumor necrosis factor-α (TNF-α) were measured with histopathological and immunohistochemical assessment of TLR4 and NF-κB in renal tissues.

RESULTS

MetS caused dyslipidemia with significant increases in body weight, SBP, FBG, serum insulin, HOMA-IR, uric acid, urea, creatinine, urinary albumin, and renal levels of Ang II, MDA, and TNF-α, whereas renal ACE2 and GSH were significantly decreased. Renal TLR4 and NF-κB immunoreactivity in MetS rats was upregulated. DIZE supplementation of MetS rats induced significant improvements in renal function parameters; this could be explained by the ability of DIZE to activate renal ACE2 and decrease renal Ang II levels with downregulation of renal TLR4 and NF-κB expression.

CONCLUSION

DIZE exerts a reno-protective effect in MetS, mainly by downregulating renal TLR4 and NF-κB levels.

Prognostic Significance of TLR2, SMAD3 and Localization-dependent SATB1 in Stage I and II Non-Small-Cell Lung Cancer Patients

This study aimed to explore the prognostic value of SATB1, SMAD3, and TLR2 expression in non-small-cell lung carcinoma patients with clinical stages I-II. To investigate, we evaluated immunohistochemical staining to each of these markers using tissue sections from 69 patients from our cohort and gene expression data for The Cancer Genome Atlas (TCGA) cohort. We found that, in our cohort, high expression levels of nuclear SATB1ⁿ and SMAD3 were independent prognostic markers for better overall survival (OS) in NSCLC patients. Interestingly, expression of cytoplasmic SATB1^c exhibited a significant but inverse association with survival rate, and it was an independent predictor of unfavorable prognosis. Likewise, TLR2 was a negative outcome biomarker for NSCLC even when adjusting for covariates. Importantly, stratification of NSCLCs with respect to combined expression of the three biomarkers allowed us to identify subgroups of patients with the greatest difference in duration of survival. Specifically, expression profile of SATB1^n-high/SMAD3^high/TLR2^low was associated with the best OS, and it was superior to each single protein alone in predicting patient prognosis. Furthermore, based on the TCGA dataset, we found that overexpression of SATB1 mRNA was significantly associated with better OS, whereas high mRNA levels of SMAD3 and TLR2 with poor OS. In conclusion, the present study identified a set of proteins that may play a significant role in predicting prognosis of NSCLC patients with clinical stages I-II.

Deep learning driven colorectal lesion detection in gastrointestinal endoscopic and pathological imaging

Colorectal cancer has the second highest incidence of malignant tumors and is the fourth leading cause of cancer deaths in China. Early diagnosis and treatment of colorectal cancer will lead to an improvement in the 5-year survival rate, which will reduce medical costs. The current diagnostic methods for early colorectal cancer include excreta, blood, endoscopy, and computer-aided endoscopy. In this paper, research on image analysis and prediction of colorectal cancer lesions based on deep learning is reviewed with the goal of providing a reference for the early diagnosis of colorectal cancer lesions by combining computer technology, 3D modeling, 5G remote technology, endoscopic robot technology, and surgical navigation technology. The findings will supplement the research and provide insights to improve the cure rate and reduce the mortality of colorectal cancer.

The Relationship between the Tissue Expression of TLR2, TLR4, TLR5, and TLR7 and Systemic Inflammatory Responses in Colorectal Cancer Patients

BACKGROUND

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy globally. CRC patients with elevated plasma C-reactive protein (CRP) levels exhibit compromised prognoses. Toll-like receptors (TLRs), activating the innate and adaptive immune systems, may contribute to pro- and antitumorigenic inflammatory responses. We aimed to identify a possible link between local and systemic inflammatory responses in CRC patients by investigating the association between tissue TLRs and plasma CRP.

METHODS

Tissue expressions of TLR2, TLR4, TLR5, and TLR7 were assessed using immunohistochemistry of tissue microarray slides from 549 CRC patients surgically treated between 1998 and 2005. Blood samples were drawn preoperatively, centrifuged, aliquoted, and stored at -80°C until analysis. Plasma CRP was determined through high-sensitivity time-resolved immunofluorometric assay. We investigated the association of TLRs to clinicopathologic variables, plasma CRP, and survival.

RESULTS

High TLR2 expression (hazard ratio [HR] 0.59; 95% confidence interval [CI] 0.41-0.85; p = 0.005), high TLR5 expression (HR 0.60; 95% CI 0.45-0.83; p = 0.002), positive TLR7 expression (HR 0.49; 95% CI 0.33-0.72; p < 0.001), and low CRP (HR 1.48; 95% CI 1.08-2.11; p = 0.017) were associated with a better prognosis. A high TLR2 immunoexpression was associated with a better prognosis among low-CRP patients (HR 0.53; 95% CI 0.35-0.80; p = 0.002), high TLR4 expression among high-CRP patients (HR 2.04; 95% CI 1.04-4.00; p = 0.038), high TLR5 expression among low-CRP patients (HR 0.059; 95% CI 0.37-0.92; p = 0.021), and positive TLR7 expression among low-CRP patients (HR 0.53; 95% CI 0.28-1.00; p = 0.049). In multivariate analyses, no biomarkers emerged as significant independent variables.

CONCLUSIONS

High tissue TLR2, TLR5, and TLR7 levels were associated with a better prognosis. Among low-CRP patients, those with high TLR2, TLR5, and TLR7 immunoexpressions exhibited a better prognosis. Among high CRP patients, a high TLR4 immunoexpression was associated with a better prognosis.

MLH1 Deficiency Down-Regulates TLR4 Expression in Sporadic Colorectal Cancer

Patients with mismatch repair (MMR)-deficient colorectal cancer (CRC) have a more favorable prognosis than patients with tumors with intact MMR. In order to obtain further insights on the reasons for this different outcome, we investigated the interplay between MMR genes and TLR4/MyD88 signaling. The cancer genome atlas (TCGA) databases were selected to predict the differential expression of TLR4 in colon cancer and its correlation with MMR genes. Moreover, the expression of MMR genes and TLR4 was evaluated by immunohistochemistry in 113 CRC samples and a cohort of 63 patients was used to assess TLR4 mRNA expression and MLH1 epigenetic silencing status. In vitro, the effect of MLH1 knockdown on TLR4 expression was quantified by Real Time PCR. TLR4 expression resulted dependent on MMR status and directly correlated to MLH1 expression. In vitro, MLH1 silencing decreased TLR4 expression. These observations may reflect the better prognosis and the chemoresistance of patients with CRC and MMR defects.

Molecular Chaperone GRP94/GP96 in Cancers: Oncogenesis and Therapeutic Target

During tumor development and progression, intrinsic and extrinsic factors trigger endoplasmic reticulum (ER) stress and the unfolded protein response, resulting in the increased expression of molecular chaperones to cope with the stress and maintain tumor cell survival. Heat shock protein (HSP) GRP94, also known as GP96, is an ER paralog of HSP90 and has been shown to promote survival signaling during tumor-induced stress and modulate the immune response through its multiple clients, including TLRs, integrins, LRP6, GARP, IGF, and HER2. Clinically, elevated expression of GRP94 correlates with an aggressive phenotype and poor clinical outcome in a variety of cancers. Thus, GRP94 is a potential molecular marker and therapeutic target in malignancies. In this review, we will undergo deep molecular profiling of GRP94 in tumor development and summarize the individual roles of GRP94 in common cancers, including breast cancer, colon cancer, lung cancer, liver cancer, multiple myeloma, and others. Finally, we will briefly review the therapeutic potential of selectively targeting GRP94 for the treatment of cancers.