Surgery for Colorectal Cancer: A Trigger for Liver Metastases Development? New Insights into the Underlying Mechanisms

Liver Metastasis in Cancer: Molecular Mechanisms and Management

Liver metastasis is a leading cause of mortality from malignant tumors and significantly impairs the efficacy of therapeutic interventions. In recent years, both preclinical and clinical research have made significant progress in understanding the molecular mechanisms and therapeutic strategies of liver metastasis. Metastatic tumor cells from different primary sites undergo highly similar biological processes, ultimately achieving ectopic colonization and growth in the liver. In this review, we begin by introducing the inherent metastatic-friendly features of the liver. We then explore the panorama of liver metastasis and conclude the three continuous, yet distinct phases based on the liver's response to metastasis. This includes metastatic sensing stage, metastatic stress stage, and metastasis support stage. We discuss the intricate interactions between metastatic tumor cells and various resident and recruited cells. In addition, we emphasize the critical role of spatial remodeling of immune cells in liver metastasis. Finally, we review the recent advancements and the challenges faced in the clinical management of liver metastasis. Future precise antimetastatic treatments should fully consider individual heterogeneity and implement different targeted interventions based on stages of liver metastasis.

Bioorthogonal targeted cell membrane vesicles/cell-sheet composites reduce postoperative tumor recurrence and scar formation of melanoma

While surgical resection is the predominant clinical strategy in the treatment of melanoma, postoperative recurrence and undetectable metastasis are both pernicious drawbacks to this otherwise highly successful approach. Furthermore, the deep cavities result from tumor excision can leave long lasting wounds which are slow to heal and often leave visible scars. These unmet needs are addressed in the present work through the use of a multidimensional strategy, and also promotes wound healing and scar reduction. In the first phase, cell membrane-derived nanovesicles (NVs) are engineered to show PD-1 and dibenzocyclooctyne (DBCO). These are capable of reactivating T cells by blocking the PD-1/PD-L1 pathway. In the second phase, azido (N3) labeled mesenchymal stem cells (MSCs) are cultured into cell sheets using tissue engineering, then apply directly to surgical wounds to enhance tissue repair. Owing to the complementary association between DBCO and N3 groups, PD-1 NVs were accumulated at the site of excision. This strategy can inhibit postoperative tumor recurrence and metastasis, whilst also promoting wound healing and reducing scar formation. The results of this study set a precedent for a new and innovative multidimensional therapeutic strategy in the postoperative treatment of melanoma.

Incidence versus treatment outcomes and survival in patients before age 40 with colorectal cancer

<b><br>Introduction:</b> Colorectal cancer (CRC) was the third most common cancer and the second cause of cancer deaths worldwide in 2020. Its incidence has increased dramatically in people under 50 years of age (early-onset colorectal cancer; EOCRC).</br> <b><br>Aim:</b> The aim of this study was to compare two age groups of patients with colorectal cancer in terms of stage, prognostic factors, survival and incidence of recurrence.</br> <b><br>Materials and methods:</b> The study group consisted of 588 patients operated on between 1995 and 2005 at the University Hospital in Krakow in the Clinical Department of General, Oncological and Gastroenterological Surgery. A method of retrospective documentation analysis was used. Patients were divided into two age groups: up to forty years of age and between 45 and 65 years of age.</br> <b><br>Results:</b> Up to 40 years of age, stage IV colorectal cancer was diagnosed in 33.3% of patients, while between 45 and 65 years of age, it was diagnosed in 26.1%. Five-year survival differed according to tumour stage. In the two groups analysed, there was a significant difference between the survival curves (P = 0.00000). Also, comparing recurrence times in the paired group excluding cancer-independent deaths revealed a statistically significant difference between the groups (P = 0.006).</br> <b><br>Discussion:</b> The incidence of colorectal cancer has increased worldwide in young people under 50 years of age, and it is therefore recommended that the research presented here be studied, and that prognostic factors be analysed and multicentre prophylactic studies combined with health education of those at risk be encouraged. Cancer occurring in younger patients is characterized by advanced stage at diagnosis and five-year survival is lower and has a poorer prognosis. The availability is very important of early diagnosis to detect pre-cancerous and considered pre-cancerous conditions is important. This involves detecting lesions at a lower stage of the disease.</br> <b><br>Conclusions:</b> The availability of early diagnosis to detect precancerous and considered pre-cancerous conditions is very important. This involves detecting lesions at a lower stage of the disease. Diagnosing colorectal cancer at an early stage and treating the pre-cancerous lesions will improve treatment outcomes, resulting in fewer metastases and longer survival and recurrence times.</br>.

OLFM2 promotes epithelial-mesenchymal transition, migration, and invasion in colorectal cancer through the TGF-β/Smad signaling pathway

BACKGROUND

Colorectal cancer (CRC) is an aggressive tumor of the gastrointestinal tract, which is a major public health concern worldwide. Despite numerous studies, the precise mechanism of metastasis behind its progression remains elusive. As a member of the containing olfactomedin domains protein family, olfactomedin 2 (OLFM2) may play a role in tumor metastasis. It is highly expressed in colorectal cancer, and its role in the metastasis of CRC is still unclear. As such, this study seeks to explore the function of OLFM2 on CRC metastasis and its potential mechanisms.

METHODS

Real-time fluorescence quantitative PCR and western blotting were used to study the expression of OLFM2 in human CRC and adjacent normal tissues. Knockdown and overexpression OLFM2 cell lines were constructed using siRNA and overexpression plasmids to explore the role of OLFM2 in the migration and invasion of CRC through transwell, and wound healing experiments. Finally, the expression of epithelial-mesenchymal transition (EMT) -related proteins and TGF-β/Smad signaling pathway-related proteins was investigated using western blotting.

RESULTS

In this study, we observed an elevation of OLFM2 expression levels in CRC tissues. To investigate the function of OLFM2, we overexpressed and knocked down OLFM2. We discovered that OLFM2 knockdown inhibited migration and invasion of colon cancer cells. Furthermore, E-cadherin expression increased while N-cadherin and Vimentin expression were opposite. It is no surprise that overexpressing OLFM2 had the opposite effects. We also identified that OLFM2 knockdown resulted in reduced TGF-βR1 and downstream molecules p-Smad2 and p-Smad3, which are related to the TGF-β / Smad pathway. In contrast, overexpressing OLFM2 significantly boosted their expression levels.

CONCLUSION

The protein OLFM2 has been identified as a crucial determinant in the progression of CRC. Its mechanism of action involves the facilitation of EMT through the TGF-β/Smad signaling pathway. Given its pivotal role in CRC, OLFM2 has emerged as a promising diagnostic and therapeutic target for the disease. These results indicate the potential of OLFM2 as a valuable biomarker for CRC diagnosis and treatment and highlight the need for further research exploring its clinical significance.

The Prognostic and therapeutic value and clinical implications of fibroblast activation protein-α as a novel biomarker in colorectal cancer

The identification of contributing factors leading to the development of Colorectal Cancer (CRC), as the third fatal malignancy, is crucial. Today, the tumor microenvironment has been shown to play a key role in CRC progression. Fibroblast-Activation Protein-α (FAP) is a type II transmembrane cell surface proteinase expressed on the surface of cancer-associated fibroblasts in tumor stroma. As an enzyme, FAP has di- and endoprolylpeptidase, endoprotease, and gelatinase/collagenase activities in the Tumor Microenvironment (TME). According to recent reports, FAP overexpression in CRC contributes to adverse clinical outcomes such as increased lymph node metastasis, tumor recurrence, and angiogenesis, as well as decreased overall survival. In this review, studies about the expression level of FAP and its associations with CRC patients' prognosis are reviewed. High expression levels of FAP and its association with clinicopathological factors have made as a potential target. In many studies, FAP has been evaluated as a therapeutic target and diagnostic factor into which the current review tries to provide a comprehensive insight. Video Abstract.

Mechanisms of colorectal liver metastasis development

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide, largely due to the development of colorectal liver metastases (CRLM). For the establishment of CRLM, CRC cells must remodel their tumor-microenvironment (TME), avoid the immune system, invade the underlying stroma, survive the hostile environment of the circulation, extravasate into the liver, reprogram the hepatic microenvironment into a permissive pre-metastatic niche, and finally, awake from a dormant state to grow out into clinically detectable CRLM. These steps form part of the invasion-metastasis cascade that relies on reciprocal interactions between the tumor and its ever-changing microenvironment. Such interplay provides a strong rational for therapeutically targeting the TME. In fact, several TME constituents, such as VEGF, TGF-β coreceptor endoglin, and CXCR4, are already targeted in clinical trials. It is, however, of utmost importance to fully understand the complex interactions in the invasion-metastasis cascade to identify novel potential therapeutic targets and prevent the establishment of CRLM, which may ultimately greatly improve patient outcome.

Epidermal Growth Factor Receptor as Target for Perioperative Elimination of Circulating Colorectal Cancer Cells

Surgical resection of the tumor is the primary treatment of colorectal cancer patients. However, we previously demonstrated that abdominal surgery promotes the adherence of circulating tumor cells (CTC) in the liver and subsequent liver metastasis development. Importantly, preoperative treatment with specific tumor-targeting monoclonal antibodies (mAb) prevented surgery-induced liver metastasis development in rats. This study investigated whether the epidermal growth factor receptor (EGFR) represents a suitable target for preoperative antibody treatment of colorectal cancer patients undergoing surgery. The majority of patients with resectable colorectal liver metastases were shown to have EGFR + CTCs. Three different anti-EGFR mAbs (cetuximab, zalutumumab, and panitumumab) were equally efficient in the opsonization of tumor cell lines. Additionally, all three mAbs induced antibody-dependent cellular phagocytosis (ADCP) of tumor cells by macrophages at low antibody concentrations in vitro, independent of mutations in EGFR signaling pathways. The plasma of cetuximab-treated patients efficiently opsonized tumor cells ex vivo and induced phagocytosis. Furthermore, neither proliferation nor migration of epithelial cells was affected in vitro, supporting that wound healing will not be hampered by treatment with low anti-EGFR mAb concentrations. These data support the use of a low dose of anti-EGFR mAbs prior to resection of the tumor to eliminate CTCs without interfering with the healing of the anastomosis. Ultimately, this may reduce the risk of metastasis development, consequently improving long-term patient outcome significantly.

Imaging α-GalCer-activated iNKT cells in a hepatic metastatic environment

Colorectal cancer patients frequently develop liver metastases after, and perhaps as a consequence of, lifesaving surgical resection of the primary tumor. This creates a potential opportunity for prophylactic metastatic treatment with novel immunostimulatory molecules. Here, we used state-of-the-art intravital imaging of an experimental liver metastasis model to visualize the early behavior and function of invariant (i)NKT cells stimulated with α-galactosylceramide (α-GalCer). Intravenous α-GalCer prior to tumor cell seeding in the liver significantly inhibited tumor growth. However, some seeding tumor cells survived. A multiple dosing regimen reduced tumor burden and prolonged the life of mice, whereas tumors returned within 5 days after a single dose of α-GalCer. With multiple doses of α-GalCer, iNKT cells increased in number and granularity (as did NK cells). As a result, the total number of contacts and time in contact with tumors increased substantially. In the absence of iNKT cells, the beneficial effect of α-GalCer was lost. Robust cytokine production dissipated over time. Repeated therapy, even after cytokine dissipation, led to reduced tumor burden and prolonged survival. Serial transplantation of tumors exposed to α-GalCer-activated iNKT cells did not induce greater resistance, suggesting no obvious epigenetic or genetic immunoediting in tumors exposed to activated iNKT cells. Very few tumor cells expressed CD1d in this model, and as such, adding monomers of CD1d-α-GalCer further reduced tumor growth. The data suggest early and repeated stimulation of iNKT cells with α-GalCer could have direct therapeutic benefit for colorectal cancer patients that develop metastatic liver disease.

Ruthenium Complexes: An Alternative to Platinum Drugs in Colorectal Cancer Treatment

Colorectal cancer (CRC) is one of the intimidating causes of death around the world. CRC originated from mutations of tumor suppressor genes, proto-oncogenes and DNA repair genes. Though platinum (Pt)-based anticancer drugs have been widely used in the treatment of cancer, their toxicity and CRC cells' resistance to Pt drugs has piqued interest in the search for alternative metal-based drugs. Ruthenium (Ru)-based compounds displayed promising anticancer activity due to their unique chemical properties. Ru-complexes are reported to exert their anticancer activities in CRC cells by regulating different cell signaling pathways that are either directly or indirectly associated with cell growth, division, proliferation, and migration. Additionally, some Ru-based drug candidates showed higher potency compared to commercially available Pt-based anticancer drugs in CRC cell line models. Meanwhile Ru nanoparticles coupled with photosensitizers or anticancer agents have also shown theranostic potential towards CRC. Ru-nanoformulations improve drug efficacy, targeted drug delivery, immune activation, and biocompatibility, and therefore may be capable of overcoming some of the existing chemotherapeutic limitations. Among the potential Ru-based compounds, only Ru (III)-based drug NKP-1339 has undergone phase-Ib clinical trials in CRC treatment.