An Explorative Analysis of ABCG2/TOP-1 mRNA Expression as a Biomarker Test for FOLFIRI Treatment in Stage III Colon Cancer Patients: Results from Retrospective Analyses of the PETACC-3 Trial

Clinical effect and safety of targeted therapy combined with chemotherapy in the treatment of patients with advanced colon cancer

Objective

To evaluate the clinical effect and safety of immunotherapy combined with chemotherapy in patients with advanced colon cancer.

Methods

This is a retrospective study. The subjects of this study were 120 patients with advanced colon cancer who were admitted to The No.2 Hospital of Baoding from November 30, 2019 to November 30, 2021. The enrolled patients were randomly divided into two groups, with 60 cases in each group. Patients in the control group were given F0LF0X4 regimen, while those in the study group were provided with Bevacizumab therapy on the basis of the method in the control group. All patients were evaluated after two cycles of treatment. The comparison of outcome measures included the curative effects, adverse drug reactions, improvement of quality-of-life scores and changes in tumor markers between the two groups.

Results

The total effective rate of the study group was significantly better than that of the control group. There was no significant difference in the incidence of adverse drug reactions between the two groups. After treatment, the study group had a significantly higher rate of improved quality of life score, while the obviously lower rate of the aggravated score than those in the control group. The levels of CEA, CA19-9 and CA125 in the study group were significantly lower than those in the control group after treatment.

Conclusion

Targeted therapy combined with chemotherapy is a safe and effective therapeutic option that has a definite curative effect in the treatment of patients with advanced colon cancer.

Using empirical biological knowledge to infer regulatory networks from multi-omics data

Background

Integration of multi-omics data can provide a more complex view of the biological system consisting of different interconnected molecular components, the crucial aspect for developing novel personalised therapeutic strategies for complex diseases. Various tools have been developed to integrate multi-omics data. However, an efficient multi-omics framework for regulatory network inference at the genome level that incorporates prior knowledge is still to emerge.

Results

We present IntOMICS, an efficient integrative framework based on Bayesian networks. IntOMICS systematically analyses gene expression, DNA methylation, copy number variation and biological prior knowledge to infer regulatory networks. IntOMICS complements the missing biological prior knowledge by so-called empirical biological knowledge, estimated from the available experimental data. Regulatory networks derived from IntOMICS provide deeper insights into the complex flow of genetic information on top of the increasing accuracy trend compared to a published algorithm designed exclusively for gene expression data. The ability to capture relevant crosstalks between multi-omics modalities is verified using known associations in microsatellite stable/instable colon cancer samples. Additionally, IntOMICS performance is compared with two algorithms for multi-omics regulatory network inference that can also incorporate prior knowledge in the inference framework. IntOMICS is also applied to detect potential predictive biomarkers in microsatellite stable stage III colon cancer samples.

Conclusions

We provide IntOMICS, a framework for multi-omics data integration using a novel approach to biological knowledge discovery. IntOMICS is a powerful resource for exploratory systems biology and can provide valuable insights into the complex mechanisms of biological processes that have a vital role in personalised medicine.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-022-04891-9.

Poziotinib Inhibits the Efflux Activity of the ABCB1 and ABCG2 Transporters and the Expression of the ABCG2 Transporter Protein in Multidrug Resistant Colon Cancer Cells

Simple Summary

Globally, colorectal cancer (CRC) is a leading cause of cancer deaths and chemotherapy, in combination with radiotherapy when appropriate, is used to treat the majority of CRC patients. However, the acquisition or development of drug resistance can decrease, or even abolish, the efficacy of chemotherapy. ATP-binding cassette (ABC) transporters, particularly, the ABCB1 and ABCG2 transporter, are mediators of multidrug resistance (MDR) in certain types of cancer cells. The aim of our in vitro study was to determine if poziotinib can overcome MDR to certain chemotherapeutic drugs in colon cancer cells. Our results indicated that in MDR CRC cell lines, poziotinib inhibits the transport function of the ABCB1 and ABCG2 transporters, increasing the intracellular accumulation of certain anticancer drugs, and thus, their efficacy. Furthermore, poziotinib decreased the expression of the ABCG2 protein. Therefore, if our results can be translated to humans, they suggest that using poziotinib in combination with certain anticancer drugs may be of therapeutic benefit in colorectal cancer patients.

Abstract

Colorectal cancer (CRC) is a leading cause of cancer deaths in the United States. Currently, chemotherapy is a first-line treatment for CRC. However, one major drawback of chemotherapy is the emergence of multidrug resistance (MDR). It has been well-established that the overexpression of the ABCB1 and/or ABCG2 transporters can produce MDR in cancer cells. In this study, we report that in vitro, poziotinib can antagonize both ABCB1- and ABCG2-mediated MDR at 0.1–0.6 μM in the human colon cancer cell lines, SW620/Ad300 and S1-M1-80. Mechanistic studies indicated that poziotinib increases the intracellular accumulation of the ABCB1 transporter substrates, paclitaxel and doxorubicin, and the ABCG2 transporter substrates, mitoxantrone and SN-38, by inhibiting their substrate efflux function. Accumulation assay results suggested that poziotinib binds reversibly to the ABCG2 and ABCB1 transporter. Furthermore, western blot experiments indicated that poziotinib, at 0.6 μM, significantly downregulates the expression of the ABCG2 but not the ABCB1 transporter protein, suggesting that the ABCG2 reversal effect produced by poziotinib is due to transporter downregulation and inhibition of substrate efflux. Poziotinib concentration-dependently stimulated the ATPase activity of both ABCB1 and ABCG2, with EC₅₀ values of 0.02 μM and 0.21 μM, respectively, suggesting that it interacts with the drug-substrate binding site. Molecular docking analysis indicated that poziotinib binds to the ABCB1 (−6.6 kcal/mol) and ABCG2 (−10.1 kcal/mol) drug-substrate binding site. In summary, our novel results show that poziotinib interacts with the ABCB1 and ABCG2 transporter, suggesting that poziotinib may increase the efficacy of certain chemotherapeutic drugs used in treating MDR CRC.

ABCG2 Protein Levels and Association to Response to First-Line Irinotecan-Based Therapy for Patients with Metastatic Colorectal Cancer

In this study we investigated the use of cancer cell protein expression of ABCG2 to predict efficacy of systemic first-line irinotecan containing therapy in patients with metastatic colorectal cancer (mCRC). From a Danish national cohort, we identified 119 mCRC patients treated with irinotecan containing therapy in first-line setting. Among these, 108 were eligible for analyses. Immunohistochemistry (IHC) analyses were performed on the primary tumor tissue in order to classify samples as high or low presence of ABCG2 protein. Data were then associated with patient outcome (objective response (OR), progression free survival (PFS) and overall survival (OS)). ABCG2 protein expression in the basolateral membrane was high (score 3+) in 33% of the patients. Exploratory analyses revealed a significant interaction between ABCG2 score, adjuvant treatment and OR (p = 0.041) in the 101 patients with evaluable disease. Patients with low ABCG2 (score 0-2) and no prior adjuvant therapy had a significantly higher odds ratio of 5.6 (Confidence Interval (CI) 1.68-18.7; p = 0.005) for obtaining OR. In contrast, no significant associations between ABCG2 expression and PFS or OS were found. These results suggest that measurement of the ABCG2 drug efflux pump might be used to select patients with mCRC for irinotecan treatment. However, additional studies are warranted before conclusions regarding a clinical use can be made. Moreover, patients with high ABCG2 immunoreactivity could be candidates for specific ABCG2 inhibition treatment in combination with irinotecan.

Different Camptothecin Sensitivities in Subpopulations of Colon Cancer Cells Correlate with Expression of Different Phospho-Isoforms of Topoisomerase I with Different Activities

The heterogeneity of tumor cells and the potential existence of rare cells with reduced chemotherapeutic response is expected to play a pivotal role in the development of drug resistant cancers. Herein, we utilized the colon cancer cell lines, Caco2 and DLD1, to investigate heterogeneity of topoisomerase 1 (TOP1) activity in different cell subpopulations, and the consequences for the chemotherapeutic response towards the TOP1 targeting drug, camptothecin. The cell lines consisted of two subpopulations: one (the stem-cell-like cells) divided asymmetrically, was camptothecin resistant, had a differently phosphorylated TOP1 and a lower Casein Kinase II (CKII) activity than the camptothecin sensitive non-stem-cell-like cells. The tumor suppressor p14ARF had a different effect in the two cell subpopulations. In the stem-cell-like cells, p14ARF suppressed TOP1 activity and downregulation of this factor increased the sensitivity towards camptothecin. It had the opposite effect in non-stem-cell-like cells. Since it is only the stem-cell-like cells that have tumorigenic activity our results point towards new considerations for future cancer therapy. Moreover, the data underscore the importance of considering cell-to-cell variations in the analysis of molecular processes in cell lines.