Myofibroblasts of the muscle layer stimulate the malignant potential of colorectal cancer

Identification of AOC3 and LRRC17 as Colonic Fibroblast Activation Markers and Their Potential Roles in Colorectal Cancer Progression

BACKGROUND

Accumulation of cancer-associated fibroblasts (CAFs) in the tumor stroma is linked to poor prognosis in colorectal cancer (CRC). CAF-cancer cell interplay, facilitated by secretomes including transforming growth factor-beta 1 (TGF-β1), supports fibroblast activation, drives colorectal carcinogenesis, and contributes to CRC aggressive phenotypes. Although widely used, traditional CAF biomarkers are found to have heterogeneous and non-specific expression. Amine oxidase copper containing 3 (AOC3) and leucine-rich repeat-containing 17 (LRRC17) have been reported to be emerging markers of myofibroblasts.

AIM

Our objective was to investigate the potential of AOC3 and LRRC17 as biomarkers for fibroblast activation thus predicting their roles in CRC progression.

METHODS

Immunofluorescence (IF) staining of AOC3 and LRRC17 was performed on myofibroblast line (CCD-112CoN), primary fibroblasts from colorectal tumor (CAFs), and adjacent normal tissue (normal fibroblasts-NFs). SW620 (epithelial CRC cell line) was used as a control.  Conventional CAF biomarker (alpha-smooth muscle actin - α-SMA) was included in the IF analysis. Fluorescence intensity was compared between groups using ImageJ software. Proliferation and contractility of treated cells were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and collagen gel contraction assays, respectively. Fibroblast contraction under TGF-β1 treatment was compared to those treated with complete medium (addition of 10% serum) and serum free (SF) medium.

RESULTS

Positive AOC3, LRRC17, and α-SMA expression were observed in colonic fibroblasts, more prominent in CAFs, whereas negative staining was found in SW620. Significant downregulation of AOC3, and upregulations in LRRC17 and α-SMA expression was found in TGF-β1-treated fibroblasts compared to SF medium treatment (p-value<0.05). All fibroblasts exhibited higher proliferation in complete medium and under treatment with conditioned medium from SW620 than SF medium. Significant contraction of NFs was recorded in complete medium and TGF-β1 (p-value<0.01).

CONCLUSION

Our results demonstrate AOC3 and LRRC17 as the potential markers of CAF activation which promote CRC progression.

Pathology and Prognosis of Colonic Adenocarcinomas With Intermediate Primary Tumor Stage Between pT2 and pT3

CONTEXT.—

Primary tumor stage (pT) is an important prognostic indicator in colonic adenocarcinomas; however, cases that have no muscle fibers beyond the advancing tumor edge but also show no extension beyond the apparent outer border of muscularis propria (termed pT2int), have not been previously studied.

OBJECTIVE.—

To address the clinicopathologic characteristics and prognosis of pT2int tumors.

DESIGN.—

We recharacterized 168 colon carcinomas and compared pT2int cases to bona fide pT2 and pT3 tumors.

RESULTS.—

In side-by-side analysis, 21 pT2int cases diverged from 29 pT2 tumors only in terms of larger size (P = .03), but they were less likely to show high-grade (P = .03), lymphovascular (P < .001), and extramural venous invasion (P = .04); discontinuous tumor deposits (P = .02); lymph node involvement (P = .001); and advanced stage (P = .001), compared with 118 pT3 tumors. Combining pT2int with pT2 cases (versus pT3) was a better independent predictor of negative lymph nodes in multivariate analysis (P = .04; odds ratio [OR], 3.96; CI, 1.09-14.42) and absent distant metastasis in univariate analysis (P = .04), compared with sorting pT2int with pT3 cases (versus pT2). Proportional hazards regression showed that pT2 and pT2int cases together were associated with better disease-free survival compared with pT3 tumors (P = .04; OR, 3.65; CI, 1.05-12.70). Kaplan-Meier analysis demonstrated that when pT2int were grouped with pT2 tumors, they were significantly less likely to show disease progression compared with pT3 (P = .002; log-rank test) and showed a trend toward better disease-specific survival (P = .06), during a mean patient follow-up of 44.9 months.

CONCLUSIONS.—

These data support the conclusion that pT2int carcinomas have clinicopathologic characteristics and are associated with patient outcomes more closely aligned with pT2 rather than pT3 tumors.

Liver Immune Microenvironment and Metastasis from Colorectal Cancer-Pathogenesis and Therapeutic Perspectives

A drastic difference exists between the 5-year survival rates of colorectal cancer patients with localized cancer and distal organ metastasis. The liver is the most favorable organ for cancer metastases from the colorectum. Beyond the liver-colon anatomic relationship, emerging evidence highlights the impact of liver immune microenvironment on colorectal liver metastasis. Prior to cancer cell dissemination, hepatocytes secrete multiple factors to recruit or activate immune cells and stromal cells in the liver to form a favorable premetastatic niche. The liver-resident cells including Kupffer cells, hepatic stellate cells, and liver-sinusoidal endothelial cells are co-opted by the recruited cells, such as myeloid-derived suppressor cells and tumor-associated macrophages, to establish an immunosuppressive liver microenvironment suitable for tumor cell colonization and outgrowth. Current treatments including radical surgery, systemic therapy, and localized therapy have only achieved good clinical outcomes in a minority of colorectal cancer patients with liver metastasis, which is further hampered by high recurrence rate. Better understanding of the mechanisms governing the metastasis-prone liver immune microenvironment should open new immuno-oncology avenues for liver metastasis intervention.

Cohesive cancer invasion of the biophysical barrier of smooth muscle

Smooth muscle is found around organs in the digestive, respiratory, and reproductive tracts. Cancers arising in the bladder, prostate, stomach, colon, and other sites progress from low-risk disease to high-risk, lethal metastatic disease characterized by tumor invasion into, within, and through the biophysical barrier of smooth muscle. We consider here the unique biophysical properties of smooth muscle and how cohesive clusters of tumor use mechanosensing cell-cell and cell-ECM (extracellular matrix) adhesion receptors to move through a structured muscle and withstand the biophysical forces to reach distant sites. Understanding integrated mechanosensing features within tumor cluster and smooth muscle and potential triggers within adjacent adipose tissue, such as the unique damage-associated molecular pattern protein (DAMP), eNAMPT (extracellular nicotinamide phosphoribosyltransferase), or visfatin, offers an opportunity to prevent the first steps of invasion and metastasis through the structured muscle.

Novel histopathological classification of meningiomas based on dural invasion

AIMS

Histological invasion into the adjacent brain parenchyma is frequently investigated in meningioma because it is an important morphological criterion for grade II meningioma according to the 2016 WHO classification. However, few studies have focused on dural invasion of meningiomas. Herein, we propose a novel histopathological classification based on dural invasion of meningiomas.

METHODS

Forty-nine cases with WHO grade I meningiomas who underwent Simpson grade I removal were collected. After the meningeal layer (ML) and periosteal layer (PL) of dura mater were visualised by Masson's trichrome stain, we evaluated the depth (to the ML and PL) and the patterns (1, expanding; 2, infiltrating) of dural invasion of meningiomas using serial paraffin sections. Invasion-associated markers, including Ki-67, matrix metalloproteinase (MMP)-1, MMP-9 and MMP-13, aquaporin 1 and Na-K-2Cl cotransporter, were quantitatively analysed by immunohistochemistry.

RESULTS

Thirty-five cases (71.4%) showed the dural invasion. In 27 of these 35 cases (77.1%), dural invasion was localised in ML. Type 1 (expanding type) and type 2 (infiltrating type) invasions were observed in 23 and 12 cases, respectively. The recurrence rate in cases with type 2 invasion was significantly higher than that in cases with type 1 invasion. The percentage of MMP-1-positive tumour cells was also significantly higher in cases with dural invasion than those without, suggesting involvement of MMP-1 in dural invasion.

CONCLUSIONS

We quantitatively evaluated the depth and patterns of dural invasion in meningiomas. The patterns of dural invasion were associated with meningioma recurrence.

The Neuropeptide System and Colorectal Cancer Liver Metastases: Mechanisms and Management

Colorectal cancer (CRC), classified as the third most prevalent cancer worldwide, remains to be a clinical and research challenge. It is estimated that ~50% of CRC patients die from distant metastases, with treatment of this complication still posing significant difficulties. While liver metastasis (LM) cascade is known in the literature, its mechanisms are still unclear and remain studied in different research models. A connection is suggested between nervous system dysfunctions and a range of Neurotransmitters (Nts) (including Neuropeptides, NPs), Neurotrophins (Ntt) and their receptors (Rs) in CRC liver metastasis development. Studies on the role of NP/NP-Rs in the progression and metastasis of CRC, show the complexity of brain–tumor interactions, caused by their different forms of release to the extracellular environment (endocrine, autocrine, paracrine and neurocrine). Many stages of LM are connected to the activity of pro-inflammatory, e.g., Corticotropin-releasing Hormone Receptor 1 (CRHR1), Neuropeptide Y (NPY) and Neurotensin (NT), anti-inflammatory, e.g., Calcitonin Gene-related Peptide (CGRP), CRHR2 and Vasoactive Intestinal Polypeptide (VIP) or dual role neuropeptides, e.g., Substance P (SP). The regulation of the local immunological profile (e.g., CRH/CRHRs), dysfunctions of enteroprotective role of NPs on epithelial cells (e.g., NT/NT-R), as well as structural-functional changes in enteric nervous system innervation of the tumor are also important. More research is needed to understand the exact mechanisms of communication between the neurons and tumor cells. The knowledge on the mechanisms regulating tumor growth and different stages of metastasis, as well as effects of the action of a numerous group of Nts/NPs/Ntt as growth factors, have implications for future therapeutic strategies. To obtain the best treatment outcomes, it is important to use signaling pathways common for many NPs, as well to develop a range of broad-spectrum antagonists. This review aims to summarize the current knowledge on the importance of neuroactive molecules in the promotion of the invasion-metastasis cascade in CRC, as well as the improvements of clinical management of CRC liver metastasis.

Efficacy of gelatin hydrogels incorporating triamcinolone acetonide for prevention of fibrosis in a mouse model

INTRODUCTION

Triamcinolone acetonide (TA), a steroid, is often used clinically to prevent dysfunctions associated with fibrosis. The objective of this study was to examine whether TA can be suspended in a gelatin sheet for tissue engineering using a mouse skin wound model.

METHODS

TA was suspended in biodegradable gelatin and freeze-dried in a sheet form. The sheet was analyzed for homogeneity and controlled release of TA by high-performance liquid chromatography. We made two skin wounds on the dorsal side of mice. Gelatin sheets with TA (TA sheet) and without TA (control sheet) were attached to each skin wound. To determine the efficacy of the prepared TA sheet on the skin wounds, TA-sheet versus TA-injection experiments were conducted. Hematoxylin and eosin staining was performed to assess the grade of epithelialization and alpha smooth muscle actin (α-SMA) immunohistochemical staining was conducted to evaluate myofibroblast infiltration.

RESULTS

In the TA-release test in vitro, 7.7 ± 2.3% of TA was released from the sheet by 24 h. After replacing the initial phosphate-buffered saline (PBS) with collagenase PBS, the amount of released TA increased over time. The wound area/original skin wound area after 15 days with the TA sheet was significantly larger than that with the control sheet (26.9 ± 5.5% vs 10.7 ± 2.6%, p = 0.023). The α-SMA positive area/whole area with the TA sheet was significantly lower than that with the control sheet (4.65 ± 0.66% vs 7.24 ± 0.7%, p = 0.023). Furthermore, the α-SMA positive area/whole area with the TA sheet was significantly lower than that with TA injection (5.32 ± 0.45% vs 7.93 ± 0.75%, p = 0.013).

CONCLUSIONS

We developed a TA sheet and confirmed both the homogeneity of the suspended TA and controlled-release of the TA in the presence of collagenase in vitro. The TA sheet caused less myofibroblast infiltration into the tissue than the control sheet or TA injection did.

Expression of cancer-associated fibroblast markers in advanced colorectal cancer

Colorectal cancer is one of the most common causes of mortality from cancer worldwide. Previous studies have demonstrated that cancer-associated fibroblasts (CAFs) promote neoangiogenesis and tumor growth for various tumors. The present study analyzed CAF markers, including α-smooth muscle actin (α-SMA), collagen I, platelet-derived growth factor receptor-β (PDGFR-β), and D2-40 (antibody recognizing podoplanin), and vessel markers, including cluster of differentiation (CD)31 and CD34, for 121 advanced colorectal cancer cases using a digital image analyzing technique. The association between CAF markers and vessel markers with clinicopathological factors was investigated. Furthermore, the association between CAF markers with each other, and their association with vessel markers was analyzed. Mean/median expression area of stromal and vessel markers in tumors were collagen I, 26.787%; D2-40, 1.372%; PDGFR-β, 11.646%; α-SMA-positive and desmin-negative myofibroblasts (α-SMA subtraction), 15.372%; CD31, 3.635%; and CD34, 2.226%. The expression area of α-SMA subtraction was significantly correlated with collagen I (P<0.001, correlation rho=0.509). High levels of α-SMA subtraction (P=0.002), collagen I (P=0.040), and PDGFR-β (P=0.040) expressions tended to be associated with high venous invasion. D2-40 did not correlate with other CAF and vessel markers. These results indicated that individual CAFs may have different expression patterns, and different strength effects for venous invasion in advanced colorectal cancer stroma.