Colorectal Cancer, Liver Metastases and Biotherapies

Single-cell transcriptomics reveals intratumor heterogeneity and the potential roles of cancer stem cells and myCAFs in colorectal cancer liver metastasis and recurrence

Metastasis and recurrence are the primary obstacles to long-term survival in colorectal cancer (CRC) patients. In this study, we employed single-cell RNA sequencing (scRNA-seq) to comprehensively delineate the transcriptomic landscape of primary and liver metastatic CRCs, and revealed novel cellular crosstalk between cancer cell subpopulation and myofibroblastic CAFs (myCAFs) at single-cell resolution. We identified a cancer cell subpopulation termed stem/transient amplifying-like (stem/TA-like) cells, which expressed genes associated with stem cell-like characteristics and metastatic potential. MyCAFs in their microenvironment showed the potential to remodel the extracellular matrix (ECM), regulate angiogenesis, and support a pro-metastatic microenvironment through paracrine signaling involving FN1, BGN, and other ECM components. Notably, we found that they may communicate through the ligand-receptor pairs FN1-CD44 and GDF15-TGFBR2, which may be linked to the liver metastatic process. Additionally, our findings suggest that both stem/TA-like cells and myCAFs could be involved in CRC recurrence following chemotherapy. A unique gene signature generated using the gene expression characteristics of stem/TA-like cells and myCAFs (SM signature) can be used to assess recurrence risk in CRC patients. Collectively, these findings highlight the intratumor heterogeneity and the potential roles of cancer stem cells and myCAFs in CRC liver metastasis and recurrence, providing new targets and insights for the prognostic assessment of CRC patients and the improved selection of effective treatment options.

Personalized prediction of postoperative complication and survival among Colorectal Liver Metastases Patients Receiving Simultaneous Resection using machine learning approaches: A multi-center study

BACKGROUND

To predict clinical important outcomes for colorectal liver metastases (CRLM) patients receiving colorectal resection with simultaneous liver resection by integrating demographic, clinical, laboratory, and genetic data.

METHODS

Random forest (RF) models were developed to predict postoperative complications and major complications (binary outcomes), as well as progression-free survival (PFS) and overall survival (OS) (time-to-event outcomes) of the CRLM patients based on data from two hospitals. The models were validated on an external dataset from an independent hospital. The clinical utility of the models was assessed via decision curve analyses (DCA).

RESULTS

There were 1067 patients included in survival prediction analyses and 1070 patients included in postoperative complication prediction analyses. The RF models provided an assessment of the model contributions of features for outcomes and suggested KRAS, BRAF, and MMR status were salient for the PFS or OS predictions. RF model of PFS showed that the Brier scores at 1-, 3-, and 5-year PFS were 0.213, 0.202 and 0.188; and the AUCs of 1-, 3- and 5-year PFS were 0.702, 0.720 and 0.743. RF model of OS revealed that Brier scores of 1-,3-, and 5-year OS were 0.040, 0.183 and 0.211; and the AUCs of 1-, 3- and 5-year OS were 0.737, 0.706 and 0.719. RF model for postoperative complication resulted in an AUC of 0.716 and a Brier score of 0.196. DCA curves clearly demonstrated that the RF models for these outcomes exhibited a superior net benefit across a wide range of threshold probabilities, signifying their favorable clinical utility. The RF models consistently exhibited robust performance in both internal cross-validation and external validation. The individualized risk profile predicted by the models closely aligned with the actual survival outcomes observed for the patients. A web-based tool (https://kanli.shinyapps.io/CRLMRF/) was provided to demonstrate the practical use of the prediction models for new patients in the clinical setting.

CONCLUSION

The predictive models and a web-based tool for personalized prediction demonstrated a moderate predictive performance and favorable clinical utilities on several key clinical outcomes of CRLM patients receiving simultaneous resection, which could facilitate the clinical decision-making and inform future interventions for CRLM patients.

Less contrast, more clarity, innovative visualization technique for management of multiple colorectal liver metastases using microwave ablation through a portal venous access

Colorectal cancer, a leading cause of cancer-related deaths, often results in liver metastases, with about half of patients affected. For those ineligibles for surgery, percutaneous microwave ablation (MWA) offers a viable alternative. Conventionally, visualizing liver lesions prior to MWA demands significant IV contrast, often needing repeated sessions. We introduce a technique using minimal IV contrast to treat multiple metastatic lesions simultaneously. A case of a 47-year-old male with stage 4 colorectal adenocarcinoma and multiple liver metastases is presented. Instead of the typical 100-150 cc of IV contrast, our method used just 25 cc, successfully ablating 6 hepatic metastases in 1 session. This approach not only reduces contrast volume but also optimizes treatment efficiency.

Exercise potentially prevents colorectal cancer liver metastases by suppressing tumor epithelial cell stemness via RPS4X downregulation

Background

Colorectal cancer (CRC) is the third most prevalent tumor globally. The liver is the most common site for CRC metastasis, and the involvement of the liver is a common cause of death in patients with late-stage CRC. Consequently, mitigating CRC liver metastasis (CRLM) is key to improving CRC prognosis and increasing survival. Exercise has been shown to be an effective method of improving the prognosis of many tumor types. However, the ability of exercise to inhibit CRLM is yet to be thoroughly investigated.

Methods

The GSE157600 and GSE97084 datasets were used for analysis. A pan-cancer dataset which was uniformly normalized was downloaded and analyzed from the UCSC database: TCGA, TARGET, GTEx (PANCAN, n = 19,131, G = 60,499). Several advanced bioinformatics analyses were conducted, including single-cell sequencing analysis, correlation algorithm, and prognostic screen. CRC tumor microarray (TMA) as well as cell/animal experiments are used to further validate the results of the analysis.

Results

The greatest variability was found in epithelial cells from the tumor group. RPS4X was generally upregulated in all types of CRC, while exercise downregulated RPS4X expression. A lowered expression of RPS4X may prolong tumor survival and reduce CRC metastasis. RPS4X and tumor stemness marker-CD44 were highly positively correlated and knockdown of RPS4X expression reduced tumor stemness both in vitro and in vivo.

Conclusion

RPS4X upregulation may enhance CRC stemness and increase the odds of metastasis. Exercise may reduce CRC metastasis through the regulation of RPS4X.

A positive feedback circuit driven by m6A-modified circular RNA facilitates colorectal cancer liver metastasis

BACKGROUND

Liver metastasis is the leading cause of death in patients with colorectal cancer (CRC). Emerge evidence suggests that circular RNA (circRNA) is a pivotal player in cancer progression. However, its role in CRC liver metastasis remains largely unknown.

METHODS

Circ-YAP expression was detected by qRT-PCR and in situ hybridization. The function of circ-YAP was tested by wound healing, transwell and CCK-8 assays. RNA immunoprecipitation, pull-down, luciferase reporter, chromatin immunoprecipitation assays were used to investigate the mechanism underlying circ-YAP promoting CRC liver metastasis. CRC liver metastasis animal model was established to assess the effect of circ-YAP in vivo.

RESULTS

Circ-YAP was notably upregulated in CRC with liver metastasis, which was associated with dismal prognosis. Circ-YAP promoted CRC cell migration and invasion in vitro, and facilitated liver metastasis in patient-derived xenografts (PDX) models in vivo. Mechanistically, circ-YAP encoded a novel truncated protein containing 220 amino acids, termed as YAP-220aa, which competitively bound to LATS1, resulting in YAP dephosphorylation and nuclear translocation, thereby activating a cohort of metastasis-promoting genes. Importantly, N6-methyladenosine (m6A) modification orchestrated efficient initiation of circ-YAP translation, requiring m6A reader YTHDF3 and eIF4G2 translation initiation complex. Intriguingly, circ-YAP was transcriptionally enhanced by YAP/TEAD complex, thus forming a positive regulatory feed-forward loop.

CONCLUSIONS

Our findings reveal a previously uncharacterized oncoprotein encoded by circ-YAP, implying a promising biomarker and therapeutic target for CRC patients with liver metastasis.

A review of targeted therapy and immune checkpoint inhibitors for metastatic colorectal cancer

Surgical resection is the cornerstone of treatment for metastatic colorectal cancer (CRC) and offers the best chance at long-term survival. Unfortunately, most patients do not present with resectable metastatic disease and, among patients who do undergo curative-intent resection, many will develop recurrence. In turn, patients require a multi-disciplinary treatment approach with a combination of chemotherapy, surgery, radiation, and/or liver directed therapies that is guided by patient disease burden and clinical status. The development of targeted therapies has led to varying success in other cancers and has emerged as a treatment option for patients with metastatic CRC. While cytotoxic chemotherapy aims to kill cells as they replicate, targeted therapies are directed at biologic features of cancers, like angiogenesis or immune checkpoints. Targeted therapy can facilitate a more treatment tailored approach to the unique genomic alterations of the tumor and hopefully deliver more personalized therapy. We herein provide a systematic review of approved targeted therapies and immune checkpoint inhibitors for metastatic CRC and provide an overview of the current literature.

Exploratory study of macrophage polarization and spatial distribution in colorectal cancer liver metastasis: a pilot study

Background

The liver is the most typical site of metastatic disease for patients with colorectal cancer (CRC), and up to half the patients with CRC will develop colorectal liver metastasis (CLM). Studying the tumor microenvironment, particularly macrophages and their spatial distribution, can give us critical insight into treatment.

Methods

Ten CLMs (five treatment-naïve and five post-neoadjuvant chemotherapy) were stained with multiplex immunofluorescence panels against cytokeratins, CD68, Arg1, CD206, CD86, CD163, PD-L1, and MRP8-14. Densities of cell phenotypes and their spatial distribution in the tumor center and the normal liver-tumor interface were correlated with clinicopathological variables.

Results

M2 macrophages were the predominant subtype in both the tumor center and the periphery, with a relatively higher density at the periphery. The larger tumors, more than 3.9 cm, were associated with higher densities of total CD68+ macrophages and CD68+CD163+ CD206neg and CD68+CD206+ CD163neg M2 macrophage subtypes. Total macrophages in the tumor periphery demonstrated significantly greater proximity to malignant cells than did those in the tumor center (p=0.0371). The presence of higher than median CD68+MRP8-14+CD86neg M1 macrophages in the tumor center was associated with poor overall survival (median 2.34 years) compared to cases with lower than median M1 macrophages at the tumor center (median 6.41 years) in univariate analysis.

Conclusion

The dominant polarization of the M2 macrophage subtype could drive new therapeutic approaches in CLM patients.