Temozolomide and Pazopanib Combined with FOLFOX Regressed a Primary Colorectal Cancer in a Patient-derived Orthotopic Xenograft Mouse Model

Network pharmacology alliance with experimental validation unveils the anti-colorectal cancer mechanism of Xianlian Jiedu decoction

ETHNOPHARMACOLOGICAL RELEVANCE

The Xianlian Jiedu Decoction (XLJDD), a traditional Chinese medicine (TCM) decoction, which is effective in clinical treatment of colorectal cancer (CRC). Nevertheless, the pharmacodynamic material basis and mechanism of its action have not been explored yet.

AIMS OF THE STUDY

To investigate the potential functional components and possible mechanism of XLJDD in anti-CRC.

MATERIALS AND METHODS

The UPLC-Q-TOF-MS method was applied to the qualification of absorbed phytochemical compounds in the plasma of rats administrated with XLJDD. Network pharmacology approach was used to create the compound-target network, GO and KEGG enrichment resolution was used to predict the potential biological mechanism of XLJDD anti-CRC. The binding of potential active ingredients to their targets was demonstrated using AutoDock Tools. And the anti-CRC efficacy of XLJDD was investigated through in vitro and in vivo experiments. Furthermore, the mechanism of XLJDD anti-CRC was validated by Western blot.

RESULTS

14 compounds from XLJDD were detected in the plasma of rats administrated with XLJDD. The results of network pharmacology analysis shown that PI3K/AKT and chemokine signaling pathways were strongly linked to XLJDD against CRC. The potential active compounds berberine, 7-methoxycoumarin and 13-methylberberubine may target PRKACA, PIK3CB, and EGFR to regulate PI3K/AKT signaling pathway, which plays a crucial role in cancer cell proliferation. In vitro experimental results revealed that XLJDD apparently inhibits the cell viability and proliferation of HCT116 cells. In vivo experimental results found that in contrast to the model group, the XLJDD treatment obviously cut down the size and weight of tumor. Further, Western blot results demonstrated that XLJDD significantly inhibited the CXCR2/PI3K/AKT signaling axis.

CONCLUSION

The therapeutic mechanism of XLJDD against CRC involves inhibiting CRC cells proliferation via modulating the CXCR2/PI3K/AKT signaling pathway.

Unveiling the antitumor synergy between pazopanib and metformin on lung cancer through suppressing p-Akt/ NF-κB/ STAT3/ PD-L1 signal pathway

Pazopanib, an inhibitor of the VEGF receptor tyrosine kinase, has demonstrated significant antitumor effects in lung cancer. However, its application as a standard treatment for this type of cancer is limited by its drug resistance and toxicity. Metformin has the potential to combat lung cancer by modifying the tumor's immune microenvironment. In this study, we investigated the potential antitumor effects and the associated underlying molecular mechanisms of the combination of pazopanib and metformin in lung cancer. In vitro studies were conducted using the A549 and H460 lung cancer cell lines, whereas urethane-induced lung cancer-bearing mice were used for in vivo assessments. The urethane-induced mice received oral administration of pazopanib (50 mg/kg) and/or metformin (250 mg/kg) for a duration of 21 days. The results indicated that the MTT assay demonstrated a combined cytotoxic effect of the pazopanib/metformin combination in H460 and A549 cells, as evidenced by CI and DRI analyses. The observed increase in annexin V levels and the corresponding increase in Caspase-3 activity strongly suggest that this combination induced apoptosis. Furthermore, the pazopanib/metformin combination significantly inhibited the p-Akt/NF-κB/IL-6/STAT3, HIF1α/VEGF, and TLR2/TGF-β/PD-L1 pathways while also increasing CD8 expression in vivo. Immunohistochemical analysis revealed that these antitumor mechanisms were manifested by the suppression of the proliferation marker Ki67. In conclusion, these findings revealed that metformin augments the antitumor efficacy of pazopanib in lung cancer by simultaneously targeting proliferative, angiogenic, and immunogenic signaling pathways, metformin enhances the antitumor effectiveness of pazopanib in lung cancer, making it a promising therapeutic option for lung cancer.

Improved Pathologic response to chemoradiation in MGMT methylated locally advanced rectal cancer

BACKGROUND AND PURPOSE

With the growing interest in total neoadjuvant treatment for locally advanced rectal adenocarcinoma (LARC) there is an urgent unmet need to identify predictive markers of response to long-course neoadjuvant concurrent chemoradiotherapy (LCRT). O6-Methylguanine (O6-MG)-DNA-methyltransferase (MGMT) gene methylation has been associated in some malignancies with response to concurrent chemoradiotherapy. We attempted to find if pathologic response to LCRT was associated with MGMT promoter hypermethylation (MGMTh).

MATERIALS AND METHODS

Patients were identified with LARC, available pre-treatment biopsy specimens, and at least 1 year of follow-up who received LCRT followed by surgical resection within 6 months. Biopsies were tested for MGMTh using a Qiagen pyrosequencing kit (Catalog number 970061). The primary outcome of LCRT responsiveness was based on tumor regression grade (TRG), with grades of 0-1 considered to have excellent response and grades of 2-3 considered to be non-responders. Secondary outcomes included overall survival (OS) and recurrence free survival (RFS).

RESULTS

Of 96 patients who met inclusion criteria, 76 had samples which produced reliable assay results. MGMTh corresponded with higher grade and age of the biopsy specimen. The percentage of responders to LCRT was higher amongst the MGMTh patients than the MGMTn patients (60.0% vs 27.5%, p value = 0.0061). MGMTh was not significantly associated with improved OS (2-year OS of 96.0% vs 98.0%, p = 0.8102) but there was a trend for improved RFS (2-year RFS of 87.6% vs 74.2%, p = 0.0903).

CONCLUSION

Significantly greater tumor regression following LCRT was seen in MGMTh LARC. Methylation status may help identify good candidates for close observation without surgery following LCRT.

BMX, a specific HDAC8 inhibitor, with TMZ for advanced CRC therapy: a novel synergic effect to elicit p53-, β-catenin- and MGMT-dependent apoptotic cell death

BACKGROUND

Despite advances in treatment, patients with refractory colorectal cancer (CRC) still have poor long-term survival, so there is a need for more effective therapeutic options.

METHODS

To evaluate the HDAC8 inhibition efficacy as a CRC treatment, we examined the effects of various HDAC8 inhibitors (HDAC8i), including BMX (NBM-T-L-BMX-OS01) in combination with temozolomide (TMZ) or other standard CRC drugs on p53 mutated HT29 cells, as well as wild-type p53 HCT116 and RKO cells.

RESULTS

We showed that HDAC8i with TMZ cotreatment resulted in HT29 arrest in the S and G2/M phase, whereas HCT116 and RKO arrest in the G0/G1 phase was accompanied by high sub-G1. Subsequently, this combination approach upregulated p53-mediated MGMT inhibition, leading to apoptosis. Furthermore, we observed the cotreatment also enabled triggering of cell senescence and decreased expression of stem cell biomarkers. Mechanistically, we found down-expression levels of β-catenin, cyclin D1 and c-Myc via GSK3β/β-catenin signaling. Intriguingly, autophagy also contributes to cell death under the opposite status of β-catenin/p62 axis, suggesting that there exists a negative feedback regulation between Wnt/β-catenin and autophagy. Consistently, the Gene Set Enrichment Analysis (GSEA) indicated both apoptotic and autophagy biomarkers in HT29 and RKO were upregulated after treating with BMX.

CONCLUSIONS

BMX may act as a HDAC8 eraser and in combination with reframed-TMZ generates a remarkable synergic effect, providing a novel therapeutic target for various CRCs. Video Abstract.

Mouse Models for Application in Colorectal Cancer: Understanding the Pathogenesis and Relevance to the Human Condition

Colorectal cancer (CRC) is a malignant disease that is the second most common cancer worldwide. CRC arises from the complex interactions among a variety of genetic and environmental factors. To understand the mechanism of colon tumorigenesis, preclinical studies have developed various mouse models including carcinogen-induced and transgenic mice to recapitulate CRC in humans. Using these mouse models, scientific breakthroughs have been made on the understanding of the pathogenesis of this complex disease. Moreover, the availability of transgenic knock-in or knock-out mice further increases the potential of CRC mouse models. In this review, the overall features of carcinogen-induced (focusing on azoxymethane and azoxymethane/dextran sulfate sodium) and transgenic (focusing on Apc^Min/+) mouse models, as well as their mechanisms to induce colon tumorigenesis, are explored. We also discuss limitations of these mouse models and their applications in the evaluation and study of drugs and treatment regimens against CRC. Through these mouse models, a better understanding of colon tumorigenesis can be achieved, thereby facilitating the discovery of novel therapeutic strategies against CRC.