Metronomic chemotherapy in metastatic colorectal cancer

Dose-dependent bidirectional pharmacological effects of vinorelbine-based metronomic combination chemotherapy on tumor growth and metastasis and mechanisms in melanoma mouse model

BACKGROUND

There is evidence that the empirical setting of doses and schedules of antineoplastic agents in metronomic chemotherapy (MC) might lead to undesirable outcomes, such as promoting tumor growth or metastasis at certain low doses. However, details about the dose effect of antineoplastic agents in MC have not been fully known yet.

OBJECTIVES

Vinorelbine combined with cisplatin or fluorouracil (VNR/CDDP or VNR/FU) was selected to investigate its effects on tumor growth or metastasis as well as mechanisms.

METHODS

Experimental techniques, including immunohistochemistry, western blot, immunofluorescence, and flow cytometry, were used to explore the mechanisms, along with cell proliferation, apoptosis, migration, and invasion.

RESULTS

The results showed that VNR/CDDP or VNR/FU promoted tumor growth and metastasis at low doses and inhibited them at high ones. Except that expressions of apoptotic proteins were elevated at both low and high doses, low-dose treatments enhanced angiogenesis and promoted the mobilization and recruitment of myeloid-derived suppressor cells (MDSCs), while high-dose treatments reversed these effects. Additionally, low concentrations of VNR/CDDP or VNR/FU stimulated tumor cell functions such as anti-apoptosis, migration, and invasion, but high concentrations only suppressed cell proliferation and increased apoptosis.

CONCLUSION

This study elucidated a bidirectional action mode regulated by multiple mechanisms at different doses in MC and also highlighted the risks of low-dose metronomic administration of antineoplastic agents in the clinic. More preclinical and clinical studies focusing on the dose-effect of metronomic regimens are urgently needed because an effective therapeutic regimen should be an optimal setting of drugs, doses, schedules, or combinations.

Glucagon Enhances Chemotherapy Efficacy By Inhibition of Tumor Vessels in Colorectal Cancer

Chemotherapy is widely used to treat colorectal cancer (CRC). Despite its substantial benefits, the development of drug resistance and adverse effects remain challenging. This study aimed to elucidate a novel role of glucagon in anti-cancer therapy. In a series of in vitro experiments, glucagon inhibited cell migration and tube formation in both endothelial and tumor cells. In vivo studies demonstrated decreased tumor blood vessels and fewer pseudo-vessels in mice treated with glucagon. The combination of glucagon and chemotherapy exhibited enhanced tumor inhibition. Mechanistic studies demonstrated that glucagon increased the permeability of blood vessels, leading to a pronounced disruption of vessel morphology. Signaling pathway analysis identified a VEGF/VEGFR-dependent mechanism whereby glucagon attenuated angiogenesis through its receptor. Clinical data analysis revealed a positive correlation between elevated glucagon expression and chemotherapy response. This is the first study to reveal a role for glucagon in inhibiting angiogenesis and vascular mimicry. Additionally, the delivery of glucagon-encapsulated PEGylated liposomes to tumor-bearing mice amplified the inhibition of angiogenesis and vascular mimicry, consequently reinforcing chemotherapy efficacy. Collectively, the findings demonstrate the role of glucagon in inhibiting tumor vessel network and suggest the potential utility of glucagon as a promising predictive marker for patients with CRC receiving chemotherapy.

Novel biomarkers used for early diagnosis and tyrosine kinase inhibitors as targeted therapies in colorectal cancer

Colorectal cancer (CRC) is the third most common and second most lethal type of cancer worldwide, presenting major health risks as well as economic costs to both people and society. CRC survival chances are significantly higher if the cancer is diagnosed and treated early. With the development of molecular biology, numerous initiatives have been undertaken to identify novel biomarkers for the early diagnosis of CRC. Pathological disorders can be diagnosed at a lower cost with the help of biomarkers, which can be detected in stool, blood, and tissue samples. Several lines of evidence suggest that the gut microbiota could be used as a biomarker for CRC screening and treatment. CRC treatment choices include surgical resection, chemotherapy, immunotherapy, gene therapy, and combination therapies. Targeted therapies are a relatively new and promising modality of treatment that has been shown to increase patients' overall survival (OS) rates and can inhibit cancer cell development. Several small-molecule tyrosine kinase inhibitors (TKIs) are being investigated as potential treatments due to our increasing awareness of CRC's molecular causes and oncogenic signaling. These compounds may inhibit critical enzymes in controlling signaling pathways, which are crucial for CRC cells' development, differentiation, proliferation, and survival. On the other hand, only one of the approximately 42 TKIs that demonstrated anti-tumor effects in pre-clinical studies has been licensed for clinical usage in CRC. A significant knowledge gap exists when bringing these tailored medicines into the clinic. As a result, the emphasis of this review is placed on recently discovered biomarkers for early diagnosis as well as tyrosine kinase inhibitors as possible therapy options for CRC.

Antiproliferative Evaluation of Novel 4-Imidazolidinone Derivatives as Anticancer Agent Which Triggers ROS-Dependent Apoptosis in Colorectal Cancer Cell

Colorectal cancer (CRC) is one of the most common causes of cancer-related death worldwide, and more therapies are needed to treat CRC. To discover novel CRC chemotherapeutic molecules, we used a series of previously synthesized novel imidazolidin-4-one derivatives to study their anticancer role in several cancer cell lines. Among these compounds, compound 9r exhibited the best anticancer activity in CRC cell lines HCT116 and SW620. We further investigated the anticancer molecular mechanism of compound 9r. We found that compound 9r induced mitochondrial pathway apoptosis in HCT116 and SW620 cells by inducing reactive oxygen species (ROS) production. Moreover, the elevated ROS generation activated the c-Jun N-terminal kinase (JNK) pathway, which further accelerated apoptosis. N-acetylcysteine (NAC), an antioxidant reagent, suppressed compound 9r-induced ROS production, JNK pathway activation, and apoptosis. Collectively, this research synthesized a series of imidazolidin-4-one derivatives, evaluated their anticancer activity, and explored the molecular mechanism of compound 9r-induced apoptosis in CRC cells. The present results suggest that compound 9r has a potential therapeutic role in CRC. Hence, it deserves further exploration as a lead compound for CRC treatment.

A novel cell senescence-related IncRNA survival model associated with the tumor immune environment in colorectal cancer

Long noncoding RNAs have a major role in tumorigenesis, development, and metastasis in colorectal cancer (CRC), participate in the regulation of cell senescence and are related to the prognosis of CRC. Therefore, it is important to validate cell senescence-related lncRNAs that correlate with prognosis in CRC.

Efficacy of bivalent CEACAM6/4-1BBL genetic vaccine combined with anti-PD1 antibody in MC38 tumor model of mice

We used mouse CRC cell line (MC38) to establish a heterotopic mouse model, and applied [⁸⁹Zr]-labeled PD-L1 antibody KN035 for PET imaging. Attenuated Salmonella typhimurium 3261 was used as an anti-tumor vaccine, and the combined anti-tumor immunotherapy with bivalent genetic vaccine and anti-PD1 antibody Nivolumab was conducted. MicroPET was performed to observe the changes of tumor tissues and expression of PD-L1. We found that the recombinant double-gene plasmids were stably expressed in COS7 cells. Study results showed the combined immunotherapy improved the effectiveness over genetic vaccine alone. This study supports that combination of genetic vaccines and anti-immunocheckpoint immunotherapy can inhibit MC38 tumor growth.

Genetic variants in RNA m5 C modification genes associated with survival and chemotherapy efficacy of colorectal cancer

BACKGROUND

Colorectal cancer is one of the most common malignant digestive tract tumors with a poor prognosis. RNA 5-methylcytosine (m⁵ C) is an important posttranscriptional widespread modification involved in many biological processes. However, the association between genetic variations of m⁵ C modification genes and the prognostic value of colorectal cancer remains unclear.

METHODS

We investigated the association between candidate single nucleotide polymorphisms (SNPs) in 13 m⁵ C modification genes and colorectal cancer overall survival (OS) after chemotherapy by the Cox regression model. The combined effect of selected SNPs on OS, progression-free survival (PFS), and disease control rate (DCR) was assessed by the number of risk alleles (NRA). The GTEx and TCGA database were used to perform expression qualitative trait locus (eQTL) analysis.

RESULTS

We identified that two SNPs in YBX1 were associated with OS after chemotherapy (HR = 1.43, p = 0.001 for rs10890208; HR = 1.36, p = 0.025 for rs3862218). A striking dose-response effect between NRA and OS after chemotherapy was found (p_trend  = 0.002). The DCR of patients receiving oxaliplatin chemotherapy in the 3-4 NRA group was markedly reduced in comparison to that in the 0-2 NRA group (OR = 1.49, p = 0.036). Moreover, YBX1 mRNA expression was significantly overexpressed in tumor tissues (p < 0.05) in the TCGA database, and eQTL analysis demonstrated that the two SNPs were associated with YBX1 (p = 0.003 for rs10890208 and p = 0.024 for rs3862218).

CONCLUSION

Our study indicates that genetic variants in m⁵ C modification genes may mediate changes in YBX1 mRNA levels and affect the chemotherapeutic efficacy of colorectal cancer patients.

Development and validation of a prognostic scoring system for patients with colorectal cancer hepato-pulmonary metastasis: a retrospective study

Background

Hepato-pulmonary metastasis of colorectal cancer (CRC) is a rare disease with poor prognosis. This study aims to establish a highly efficient nomogram model to predict overall survival (OS) and cancer-specific survival (CSS) in patients with colorectal cancer hepato-pulmonary metastasis (CRCHPM).

Methods

We retrospectively analyzed the data of patients with CRCHPM from SEER database and Wuhan Union Hospital Cancer Center (WUHCC). A total of 1250 CRCHPM patients were randomly assigned to the training, internal validation, and external validation cohorts from 2010 to 2016.Univariate and multivariate cox analysis were performed to identify independent clinicopathological predictors of OS and CSS, and a nomogram was constructed to predict OS and CSS in CRCHPM patients.

Results

A nomogram of OS was constructed based on seven independent predictors of age, degree of differentiation, T stage, chemotherapy, number of lsampled lymph nodes, number of positive lymph nodes, and tumor size. Nomogram showed favorable sensitivity in predicting OS at 1, 3 and 5 years, with area under the receiver operating characteristic curve (AUROC) values of 0.802, 0.759 and 0.752 in the training cohort;0.814, 0.769 and 0.716 in the internal validation cohort;0.778, 0.756 and 0.753 in the external validation cohort, respectively. A nomogram of CSS was constructed based on three independent predictors of T stage, chemotherapy, and tumor size. The AUROC values of 1, 3 and 5 years were 0.709,0.588,0.686 in the training cohort; 0.751, 0.648,0.666 in the internal validation cohort;0.781,0.588,0.645 in the external validation cohort, respectively. Calibration curves, Concordance index (C-index), and decision curve analysis (DCA) results revealed that using our model to predict OS and CSS is more efficient than other single clinicopathological characteristics.

Conclusion

A nomogram of OS and CSS based on clinicopathological characteristics can be conveniently used to predict the prognosis of CRCHPM patients.

LncRNA LINC01315 silencing modulates cancer stem cell properties and epithelial-to-mesenchymal transition in colorectal cancer via miR-484/DLK1 axis

Long non-coding RNA long intergenic non-protein coding RNA 01315 (LncRNA LINC01315) has been found to be implicated in various cancers, but its role and functions in colorectal cancer (CRC) remain to be addressed. Data on LINC01315 expression in CRC were gathered using bioinformatics analysis, and cancer stem cells (CSCs) were sorted by aldehyde dehydrogenase (ALDH) assay and flow cytometry. Migration, invasion, and stemness of CSCs isolated from CRC cells after transfection were determined by scratch, Transwell, and sphere-formation assays, respectively. Tumor xenograft model was constructed. Target genes and potential-binding sites were predicted using online databases and further confirmed via dual-luciferase reporter assay. Relative factors expressions were determined via quantitative real-time polymerase-chain reaction and Western blot as needed. LINC01315 was high-expressed in CRC and ALDH⁺ cells. LINC01315 silencing suppressed the migration, invasion, and sphere formation of CRC cells and tumor growth, and downregulated expressions of CSC molecules (ALDH, cluster of difference 44 (CD44), Prominin, and sex determining region Y-box 2 (SOX2)), Zinc Finger E-Box Binding Homeobox 1 (ZEB1) and Vimentin but upregulated E-Cadherin expression. MiR-484 could competitively bind with LINC01315, and LINC01315 silencing promoted miR-484 expression. The level of Delta Like Non-Canonical Notch Ligand 1 (DLK1), the target gene of miR-484, was enhanced by overexpressed LINC01315 yet was suppressed by LINC01315 silencing. Also, DLK1 silencing reversed the effects of downregulated miR-484 on migration, invasion, sphere formation, and CSC molecules expressions in CRC cells. LINC01315 silencing modulated CSC properties and epithelial-to-mesenchymal transition via miR-484/DLK1 axis.

Predicting Distant Metastasis in Young-Onset Colorectal Cancer After Surgery: A Retrospective Study

Background

Although overall colorectal cancer (CRC) cases have been declining worldwide, there has been an increase in the incidence of the CRC among individuals younger than 50 years old, which is associated with distant metastasis (DM) and poor prognosis.

Methods

Young-onset CRC patients' postoperative data were collected from the Surveillance, Epidemiology, and End Results (SEER) database between January 2010 and December 2015. Data from the SEER database were divided into early stage and advanced stage according to whether chemoradiotherapy was recommended in the guidelines. Independent risk factors for DM were explored by using univariate and multivariate logistic regression separately. A predictive model was established and presented as nomogram in the training set of advanced stage. The model was internally verified in testing set and externally validated in a cohort of 145 patients from Zhongnan Hospital of Wuhan University. The accuracy, reliability, and clinical application value were assessed using the receiver operating characteristic curve (ROC), the area under the curve (AUC), calibration curve, and decision curve analysis (DCA), respectively. Different risk subgroups of DM were classified according to the scores of the nomogram in the training set of advanced stage.

Results

A total of 5,584 patients were eligible and enrolled in our study in which 1,277 were in early stage and 4,307 in advanced stage. Preoperative CEA positive was found to be an independent predictor of DM in early stage. Multivariate logistic regression analysis showed that tumor size, degree of differentiation, T stage, N stage, preoperative CEA, and whether radiation or chemotherapy performed were independent risk factors for DM (all, p < 0.05) in advanced stage. Great accuracies were achieved in our nomogram with AUC of 0.801 in training set, 0.811 in testing set, and 0.791 in the validation cohort, respectively. Calibration curves and DCA in internal validation and external validation both showed good stability and clinical utility values.

Conclusions

Preoperative CEA positive was a significant predictor of DM for young-onset CRC patients. A novel nomogram containing clinical and pathological features was established for predicting DM of advanced CRC in patients younger than 50 years old. This tool may serve as an early alert for clinicians to DM and make better clinical treatment regimens.

Exosomal transfer of circ_0006174 contributes to the chemoresistance of doxorubicin in colorectal cancer by depending on the miR-1205/CCND2 axis

Exosomes are the mediators of intercellular signal transduction, and they have been involved in the carcinogenesis and chemoresistance of tumor cells. Herein, we intended to investigate whether circular RNA (circRNA) circ_0006174 can regulate chemoresistance of doxorubicin (DOX) in colorectal cancer via exosomes. Forty-one pairs of normal and CRC (DOX sensitive, n = 16; DOX resistant, n = 25) samples were collected. The resistant cell lines (LoVo/DOX and HCT116/DOX) were constructed by exposure of parental cell lines (LoVo and HCT116) to DOX. The detection of circ_0006174, microRNA-1205 (miR-1205), and cyclin D2 (CCND2) was performed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell Counting Kit-8(CCK-8) was applied for determining the half of inhibitory concentration (IC50) of DOX and cell proliferation. The migration and invasion capacities were analyzed via transwell assay. Exosomes were extracted using ultracentrifugation. Protein levels were determined using western blot. Dual-luciferase reporter assay was used for affirming target interaction. In vivo experiment was performed by establishing xenograft models in mice. Circ_0006174 level was upregulated in DOX-resistant CRC tissues and cells. The downregulation of circ_0006174 inhibited DOX resistance, cell proliferation, migration, and invasion in DOX-resistant CRC cells. Interestingly, the abundant circ_0006174 was enriched in exosomes derived from DOX-resistant CRC cells. Furthermore, circ_0006174 could enhance DOX resistance via the exosomal intercellular transfer. Moreover, we validated the target relation of circ_0006174/miR-1205 or miR-1205/CCND2. The effect of exosomal circ_0006174 on DOX resistance was achieved by upregulating the miR-1205-mediated CCND2. In vivo, knockdown of circ_0006174 also enhanced tumor sensitivity to DOX by targeting miR-1205/CCND2 axis. Altogether, these findings unraveled that circ_0006174-enriched exosomes elevated DOX chemoresistance in CRC by the miR-1205/CCND2 axis. The exosomal circ_0006174 can be used as an available biomarker for the diagnosis of chemoresistance in CRC.

Metronomic Therapy in Oral Squamous Cell Carcinoma

Metronomic therapy is characterized by drug administration in a low-dose, repeated, and regular manner without prolonged drug-free interval. The two main anticancer mechanisms of metronomic therapy are antiangiogenesis and immunomodulation, which have been demonstrated in several delicate in vitro and in vivo experiments. In contrast to the traditional maximum tolerated dose (MTD) dosing of chemotherapy, metronomic therapy possesses comparative efficacy but greatlydecreases the incidence and severity of treatment side-effects. Clinical trials of metronomic anticancer treatment have revealed promising results in a variety cancer types and specific patient populations such as the elderly and pediatric malignancies. Oral cavity squamous cell carcinoma (OCSCC) is an important health issue in many areas around the world. Long-term survival is about 50% in locally advanced disease despite having high-intensity treatment combined surgery, radiotherapy, and chemotherapy. In this article, we review and summarize the essence of metronomic therapy and focus on its applications in OCSCC treatment.

Anti-Cancer Treatment Strategies in the Older Population: Time to Test More?

Aging is a well-recognized risk factor for the development of cancer. The incidence of new cancer diagnoses has increased globally given the rising senior population. Many hypotheses for this increased risk have been postulated over decades, including increased genetic and epigenetic mutations and the concept of immunosenescence. The optimal treatment strategies for this population with cancer are unclear. Older cancer patients are traditionally under-represented in clinical trials developed to set the standard of care, leading to undertreatment or increased toxicity. With this background, it is crucial to investigate new opportunities that belong to the most recent findings of an anti-cancer agent, such as immune-checkpoint inhibitors, to manage these daily clinical issues and eventually combine them with alternative administration strategies of antiblastic drugs such as metronomic chemotherapy.

Nomogram for predicting overall survival in colorectal cancer with distant metastasis

Background

Colorectal cancer (CRC) is a major cancer burden, and prognosis is determined by many demographic and clinicopathologic factors. The present study aimed to construct a prognostic nomogram for colorectal cancer patients with distant metastasis.

Methods

Colorectal cancer patients with distant metastasis diagnosed between 2010 and 2016 were selected from the Surveillance, Epidemiology, and End Results database. Cox proportional hazards regression was used to identify independent prognostic factors. A nomogram was constructed to predict survival, and validation was performed.

Results

A total of 7099 stage IV colorectal cancer patients were enrolled in the construction cohort. The median overall survival was 20.0 (95% CI 19.3–20.7) months. Age at diagnosis, marital status, race, primary tumour site, tumour grade, CEA level, T stage, N stage, presence of bone, brain, liver and lung metastasis, surgery for primary site and performance of chemotherapy were independent prognostic factors. The nomogram was constructed and the calibration curve showed satisfactory agreement. The C-index was 0.742 (95% CI 0.726–0.758). In the validation cohort (7098 patients), the nomogram showed satisfactory discrimination and calibration with a C-index of 0.746 (95% CI 0.730–0.762).

Conclusion

A series of factors associated with the survival of CRC patients with distant metastasis were found. Based on the identified factors, a nomogram was generated to predict the survival of stage IV colorectal cancer patients. The predictive model showed satisfactory discrimination and calibration, which can provide a reference for survival estimation and individualized treatment decisions.

Capecitabine in treating patients with advanced, persistent, or recurrent cervical cancer: an active and safe option?

Introduction: Advanced, persistent or recurrent cervical cancer in patients not amenable to curative surgery or radiotherapy predicts a dismal prognosis. Systemic chemotherapy based on paclitaxel/cisplatin ± bevacizumab is the current standard of care. However, once progression occurs, the possibility of alternative treatment options is very limited.Areas covered: The usefulness of capecitabine has been well-established against several cancer types, including head and neck, breast, and colorectal cancer. This review covers current literature evidence on the clinical efficacy and safety of capecitabine in cervical cancer treatment, either as monotherapy or combined with other agents or chemo-radiotherapy.Expert opinion: Recent clinical data, albeit scant, suggested a promising role for capecitabine both as monotherapy in patients with platinum-resistant cervical cancer and in combination with cisplatin in chemotherapy-naïve patients with metastatic or recurrent cervical cancer. In our opinion, capecitabine, especially in combination regimens, could represent a valid treatment option and further research is warranted to better understand its effectiveness in these challenging patients.

VEGFR2-targeted antibody fused with IFN mut regulates the tumor microenvironment of colorectal cancer and exhibits potent anti-tumor and anti-metastasis activity

Although interferon α (IFNα) and anti-angiogenesis antibodies have shown appropriate clinical benefit in the treatment of malignant cancer, they are deficient in clinical applications. Previously, we described an anti-vascular endothelial growth factor receptor 2 (VEGFR2)-IFNα fusion protein named JZA01, which showed increased in vivo half-life and reduced side effects compared with IFNα, and it was more effective than the anti-VEGFR2 antibody against tumors. However, the affinity of the IFNα component of the fusion protein for its receptor-IFNAR1 was decreased. To address this problem, an IFNα-mutant fused with anti-VEGFR2 was designed to produce anti-VEGFR2-IFNαmut, which was used to target VEGFR2 with enhanced anti-tumor and anti-metastasis efficacy. Anti-VEGFR2-IFNαmut specifically inhibited proliferation of tumor cells and promoted apoptosis. In addition, anti-VEGFR2-IFNαmut inhibited migration of colorectal cancer cells and invasion by regulating the PI3K–AKT–GSK3β–snail signal pathway. Anti-VEGFR2-IFNαmut showed superior anti-tumor efficacy with improved tumor microenvironment (TME) by enhancing dendritic cell maturation, dendritic cell activity, and increasing tumor-infiltrating CD8⁺ T cells. Thus, this study provides a novel approach for the treatment of metastatic colorectal cancer, and this design may become a new approach to cancer immunotherapy.

Clinical Perspectives on Liquid Biopsy in Metastatic Colorectal Cancer

Liquid biopsy, which generally refers to the analysis of biological components such as circulating nuclear acids and circulating tumor cells in body fluids, particularly in peripheral blood, has shown good capacity to overcome several limitations faced by conventional tissue biopsies. Emerging evidence in recent decades has confirmed the promising role of liquid biopsy in the clinical management of various cancers, including colorectal cancer, which is one of the most prevalent cancers and the second leading cause of cancer-related deaths worldwide. Despite the challenges and poor clinical outcomes, patients with metastatic colorectal cancer can expect potential clinical benefits with liquid biopsy. Therefore, in this review, we focus on the clinical prospects of liquid biopsy in metastatic colorectal cancer, specifically with regard to the recently discovered various biomarkers identified on liquid biopsy. These biomarkers have been shown to be potentially useful in multiple aspects of metastatic colorectal cancer, such as auxiliary diagnosis of metastasis, prognosis prediction, and monitoring of therapy response.

Gene Expression Signatures of a Preclinical Mouse Model during Colorectal Cancer Progression under Low-Dose Metronomic Chemotherapy

Understanding the molecular signatures of colorectal cancer progression under chemotherapeutic treatment will be crucial for the success of future therapy improvements. Here, we used a xenograft-based mouse model to investigate, how whole transcriptome signatures change during metastatic colorectal cancer progression and how such signatures are affected by LDM chemotherapy using RNA sequencing. We characterized mRNAs as well as non-coding RNAs such as microRNAs, long non-coding RNAs and circular RNAs in colorectal-cancer bearing mice with or without LDM chemotherapy. Furthermore, we found that circZNF609 functions as oncogene, since over-expression studies lead to an increased tumor growth while specific knock down results in smaller tumors. Our data represent novel insights into the relevance of non-coding and circRNAs in colorectal cancer and provide a comprehensive resource of gene expression changes in primary tumors and metastases. In addition, we present candidate genes that could be important modulators for successful LDM chemotherapy.

Metronomic capecitabine as maintenance treatment after first line induction with XELOX for metastatic colorectal cancer patients

Maintenance treatment after first-line chemotherapy for patients with metastatic colorectal cancer (mCRC) is a priority strategy. However, which medicine is chosen is controversial. This study aimed to determine the efficacy and safety of maintenance treatment with metronomic capecitabine vs observation.In this randomized controlled trial, patients who completed 18 weeks of induction chemotherapy with XELOX and achieved disease control were randomly assigned centrally (1:1) to receive maintenance therapy with metronomic chemotherapy or observation until disease progression. The primary endpoint was progression-free survival from randomization; secondary endpoints included overall survival and safety. Analyses were performed by intention to treat.Between January 1st, 2017 and December 31th 2018, 48 patients were enrolled and randomly assigned to receive maintenance treatment with metronomic capecitabine (n = 25) or only observation (n = 23). The median progression-free survival in the metronomic capecitabine group was 5.66 (95% confidence interval [CI] 5.25-6.07) months vs 3.98 (95%CI 3.71-4.24) months in the observation group (hazard ratio 0.11, 95% [CI] 0.04-0.26, P = .000). There was no statistically significant difference in median overall survival: 23.82 (95% CI 22.38-25.25) months in the metronomic capecitabine group vs 21.81 (95% CI 20.23-23.38) months in the observation group (hazard ratio 0.49, 95% CI 0.21-1.11, P = .087). Subgroup analyses were generally consistent with the primary finding. Similar safety profiles were observed in both arms. The most frequent adverse events in metronomic capecitabine group included neutropenia, diarrhea, hand-foot skin reaction, and mucositis.Maintenance therapy with metronomic capecitabine can be considered an alternative option following first-line chemotherapy of XELOX in patients with metastatic colorectal cancer with controlled toxicities.

Prognostic Value of EGFR Expression for Patients With Stage III Colorectal Cancer Receiving Fluoropyrimidine Metronomic Maintenance Therapy After Radical Resection and Adjuvant Oxaliplatin-Based Chemotherapy

This study evaluated the survival effects of metronomic maintenance therapy with oral fluoropyrimidine in patients with stage III colorectal cancer (CRC) according to epidermal growth factor receptor (EGFR) expression. We enrolled 197 patients with stage III CRC who had undergone radical resection and FOLFOX regimen adjuvant chemotherapy. The clinicopathological features and effects of metronomic maintenance therapy with oral capecitabine (daily dose of 850 mg/m², twice daily, on days 1–14 every 3 weeks for 6 months) on survival according to treatment group and EGFR expression were analyzed. By conducting an in vitro cell line study and in vivo study through knockout of the EGFR gene, we analyzed the capacities of cell proliferation and migration. Relapse and survival were significantly more common in the FOLFOX group. Metronomic maintenance therapy was a significantly independent associated factor of relapse and survival as well as a prognostic factor of disease-free survival and overall survival. Significant intergroup differences in survival were only observed in patients with positive EGFR expression. Thus, our findings suggest EGFR expression is a prognostic factor in patients with stage III CRC receiving metronomic maintenance therapy. Analysis of EGFR expression in these patients helps identify potential candidates who may receive the optimal survival benefit from metronomic maintenance therapy.

Inhibition of ALAS1 activity exerts anti-tumour effects on colorectal cancer in vitro

BACKGROUND/AIMS

Colorectal cancer (CRC) is the third most common malignant tumour worldwide and the second leading cause of cancer-related deaths. Commonly, 5'-aminolevulinic acid synthase1 (ALAS1) is the rate-limiting enzyme for haem biosynthesis. Recent studies have shown that ALAS1 is involved in a number of cellular functions and has significant effects on non-small cell lung cancer (NSCLC). However, current concepts of disease pathogenesis fail to fully explain the role of ALAS1 expression and biological functions in CRC.

MATERIALS AND METHODS

A total of 67 paired tumour tissues and adjacent colorectal tissues were used to detect ALAS1 levels and further analyse the correlation between ALAS1 expression levels and clinical features. Using HCT116 cell lines, we studied the impact of ALAS1 on biological function by knocking down or inhibiting ALAS1.

RESULTS

We found an increase in the levels of ALAS1 in cancer tissues compared to adjacent colorectal tissues. The increase in ALAS1 expression was closely related to the invasion depth, N staging and tumour size of CRC patients. The proliferation and metastasis of CRC cells could be inhibited by suppressing ALAS1.

CONCLUSIONS

The abnormal expression of ALAS1 is closely related to the proliferation and metastasis of CRC cells, suggesting that ALAS1 may be a novel therapeutic target for the treatment of CRC.

Inhibition of miR-19a partially reversed the resistance of colorectal cancer to oxaliplatin via PTEN/PI3K/AKT pathway

Oxaliplatin is a platinum-based chemotherapeutic drug that is effective and commonly used in the treatment of colorectal cancer (CRC). However, long-term use of oxaliplatin usually induces significant drug resistance. It is urgent to develop strategies to reverse the oxaliplatin resistance to CRC cells. In the present study, we established the model of oxaliplatin-resistant CRC cell lines (SW480/R and HT29/R) through continuous treatment of SW480 and HT29 cells with oxaliplatin. Results of qRT-PCR analysis showed that expression of miR-19a was significantly increased in SW480/R and HT29/R compared to their parental SW480 and HT29. However, combination treatment with anti-miR-19a, an antisense oligonucleotide of miR-19a, was found to resensitize SW480/R and HT29/R cells to oxaliplatin treatment. In the mechanism research, we found that anti-miR-19a increased the expression of PTEN and thus inhibited the phosphorylation of PI3K and AKT in SW480/R and HT29/R cells. As a result, mitochondrial apoptosis induced by oxaliplatin was expanded. We demonstrated that PTEN was the target of miR-19a and inhibition of miR-19a partially reversed the resistance of colorectal cancer to oxaliplatin via PTEN/PI3K/AKT pathway.

Synergy between Auranofin and Celecoxib against Colon Cancer In Vitro and In Vivo through a Novel Redox-Mediated Mechanism

Recent study suggests that auranofin (AF), a US Food and Drug Administration (FDA)-approved drug for treatment of rheumatoid arthritis, has selective anticancer activity in various experimental models. Its clinical applications in cancer treatment, however, have been hampered due in part to its relatively moderate activity as a single agent. In this study, we performed a high-throughput screening of the FDA-approved drug library for clinical compounds that potentiate the anticancer activity auranofin, and unexpectedly identified an anti-inflammatory drug celecoxib (CE) that potently enhanced the therapeutic activity of AF in vitro and in vivo. Mechanistically, AF/CE combination induced severe oxidative stress that caused ROS-mediated inhibition of hexokinase (HK) and a disturbance of mitochondrial redox homeostasis, resulting in a significant decrease of ATP generation. The CE-induced ROS increase together with AF-medicated inhibition of thioredoxin reductase cause a shift of Trx2 to an oxidized state, leading to degradation of MTCO2 and dysfunction of the electron transport chain. Our study has identified a novel drug combination that effectively eliminates cancer cells in vivo. Since AF and CE are FDA-approved drugs that are currently used in the clinic, it is feasible to translate the findings of this study into clinical applications for cancer treatment.

The oncogenic role of Wnt10a in colorectal cancer through activation of canonical Wnt/β-catenin signaling

Colorectal cancer (CRC) is one of the major causes of cancer-associated mortality worldwide. Wnt family member 10A (Wnt10a) is an oncogene associated with the carcinogenesis and progression of renal cell carcinoma, and is strongly expressed in the CRC cell line SW480. However, the role of Wnt10a in CRC has been rarely reported. In the present study, the expression levels of Wnt10a were higher in 40 tumor tissues compared with in paired control tissues, as determined by RT-qPCR method. In addition, the clinic opathological association analysis indicated that Wnt10a expression was associated with tumor stage (T3+T4, P=0.015). Furthermore, Wnt10a was highly expressed in the SW480, SW620 and HCT116 cell lines. In order to explore the role of Wnt10a in CRC, Wnt10a expression was knocked down by siRNA technology in HCT116 cell line. Cell proliferation was significantly inhibited by 55% in CCK-8 assay following Wnt10a knockdown and cell migration rate was decreased by 50% in Transwell assay. In addition, western blot analysis demonstrated that Wnt10a knockdown decreased the expression levels of β-catenin, cyclin D1, lymphoid enhancer-binding factor 1 and protein kinase B, which was consistent with results obtained with the Wnt/β-catenin specific inhibitor LGK-974. It was thus suggested that Wnt10a downregulation inactivated the Wnt/β-catenin signaling pathway in HCT116 cells. In conclusion, the present study demonstrated that Wnt10a may have an oncogenic role during carcinogenesis of CRC through activation of Wnt/β-catenin signaling.

Tumor endothelial cells as a potential target of metronomic chemotherapy

Drug resistance and toxic side effects are major therapeutic hurdles affecting cancer patients receiving conventional chemotherapy based on the maximum tolerated dose. Metronomic chemotherapy (MCT), a new therapeutic approach developed to avoid these problems generally, consists of the continuous administration of low-dose cytotoxic agents without extended intervals. This therapy targets the tumor microenvironment, rather than exerting a direct effect on tumor cells. As a result, the MCT regimen functionally impairs tumor endothelial cells and circulating endothelial progenitor cells, leading to tumor dormancy via anti-angiogenesis. Over the past 10 years, several studies have highlighted the impact of MCT on the tumor microenvironment and angiogenesis and demonstrated its potential as a switch from the pro-angiogenic to the anti-angiogenic state. However, the mechanisms of action are still obscure. Here, we systematically review the evidence regarding the anti-angiogenic potential of MCT as a crucial determinant of tumor dormancy and cancer treatment.

Asiatic acid inhibits proliferation, migration and induces apoptosis by regulating Pdcd4 via the PI3K/Akt/mTOR/p70S6K signaling pathway in human colon carcinoma cells

Previous studies have demonstrated that asiatic acid (AA), the major component of Centella asiatica, is able to meditate cytotoxic and anticancer effects on various types of carcinoma cells. In order to investigate the molecular mechanism that underlies the antitumor effect of AA, the present study investigated the effects of AA on proliferation, migration and apoptosis of SW480 and HCT116 colon cancer cells. Viability and changes in cell morphology in the cells were assessed by MTT assay and transmission electron microscopy, respectively. Colony formation analysis was used to observe proliferation of the single cell, and migratory ability of the cells was assessed by performing Transwell migration assay. Hoechst 33342 nuclear staining and flow cytometry were used to assess apoptosis in colon carcinoma cells. The expression of proteins associated with the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR)/p70S6K signaling pathway and epithelial-mesenchymal transition (EMT) marker were analyzed by western blotting. The present study revealed that proliferation and migration of colon carcinoma cells were inhibited by AA in a dose-dependent and time-dependent manner. Numerous apoptotic bodies were observed, and G₂/M and S phase progression were delayed in colon cancer cells treated with AA, but not in the control group. A number of phosphorylated proteins, including PI3K, Akt (Ser⁴⁷³), mTOR, ribosomal protein S6 kinase (p70S6K) downregulated, while the expression of Pdcd4 was upregulated following treatment with AA. Additionally, AA affects expression of EMT markers in a dose-dependent manner. On the basis of these results, it was concluded that AA inhibited proliferation, migration and induced apoptosis of colon cancer cells by regulating Pdcd4 via the PI3K/Akt/mTOR/p70S6K signaling pathway. These observations suggest that AA may be a potential therapeutic agent for the treatment of colon carcinoma.

Pharmacokinetic analysis of metronomic capecitabine in refractory metastatic colorectal cancer patients

The aim of the present study was to assess the pharmacokinetics (PK) of metronomic capecitabine and its metabolites in a population of refractory metastatic colorectal cancer (mCRC) patients. Thirty-four patients (M/F, 22/12) with a diagnosis of mCRC received capecitabine 800 mg p.o. twice a day and cyclophosphamide 50 mg/day p.o. Blood samples were collected at baseline, 15 min, 30 min, 1 h, 1.5 h, 2 h, 3 h and 5 h at day 1 after capecitabine administration. Plasma concentrations of capecitabine and its metabolites were measured by high performance liquid chromatography and the main PK parameters were calculated. Maximum plasma concentrations (C_max) of capecitabine (11.51 ± 9.73 μg/ml) occurred at 0.5 h, whereas the C_max of 5'-deoxy-5-fluorocytidine (5'-DFCR; 2.45 ± 2.93 μg/ml), 5'-deoxy-5-fluorouridine (5'-DFUR; 6.43 ± 8.2 μg/ml), and 5-fluorouracil (5-FU; 0.24 ± 0.16 μg/ml) were found at 1 h, 1.5 h and 1 h, respectively. Capecitabine, 5'-DFCR, 5'-DFUR and 5-FU AUCs at day 1 were 21.30 ± 10.78, 5.2 ± 4.6, 19.59 ± 3.83 and 0.66 ± 0.77 hxμg/ml, respectively. In conclusion, low doses of capecitabine were rapidly absorbed and extensively metabolized, achieving measurable plasma concentrations in a heavily pretreated population of patients.

Targeted delivery of miRNA-204-5p by PEGylated polymer nanoparticles for colon cancer therapy

AIM

miRNAs have been recognized for their potential in cancer therapeutics, and multiple miRNAs were suggested to affect target genes expression. To overcome limitations of free synthetic miRNAs, such as easily degraded in biofluids and limited in cellular uptake, novel miRNAs delivery systems need to be developed.

MATERIALS & METHODS

Using surface-functionalizing technique, poly(D,L-lactide-co-glycolide)/poly(L-lactide)-block-poly(ethylene glycol)-folate polymer nanoparticle (PLGA/PLA-PEG-FA) loaded with miR-204-5p (FA-NPs-miR-204) was developed. The therapeutic efficacy of FA-NPs-miR-204 was evaluated in the Luc-HT-29 xenograft tumor model in vivo.

RESULTS

FA-NPs-miR-204 could be taken up by HT-29  and HCT-116 cells efficiently, resulting in significant inhibitory effect on cell proliferation and promotive effect on cell apoptosis. In vivo study showed that FA-NPs-miR-204 could exert tumor suppressive function in Luc-HT-29 xenograft model.

CONCLUSION

Our study demonstrates a convenient miRNA delivery system that targets tumor tissue and exerts tumor suppressive function, thus demonstrating a potential new therapeutic option for colon cancer.