Systemic treatment of advanced colorectal cancer: tailoring therapy to the tumor

Bipyridine Derivatives as NOP2/Sun RNA Methyltransferase 3 Inhibitors for the Treatment of Colorectal Cancer

Based on the structure of caerulomycin A, 90 novel bipyridine derivatives were designed and synthesized. Among these, compound B19 exerted strong antitumor effects in vivo and in vitro. Importantly, NOP2/Sun RNA methyltransferase 3 (NSUN3) protein was identified as the target specific binding to B19, which inhibits oxidative phosphorylation of mitochondrial energy metabolism and enhances glycolytic activity by binding to NSUN3. Knockdown of NSUN3 inhibited both proliferation and migration of colorectal cancer (CRC) cells by activating AMPK-related signaling and inhibiting downstream STAT3 signaling to exert antiproliferative and pro-apoptotic effects. Our findings support the use of NSUN3 inhibitors as promising therapeutic strategies against CRC.

Stimuli-Responsive Liposomes of 5-Fluorouracil: Progressive Steps for Safe and Effective Treatment of Colorectal Cancer

5-Fluorouracil (5-FU) has become one of the most widely employed antimetabolite chemotherapeutic agents in recent decades to treat various types of cancer. It is considered the standard first-line treatment for patients with metastatic colorectal cancer. Unfortunately, traditional chemotherapy with 5-FU presents many limitations, such as a short half-life, a low bioavailability, and a high cytotoxicity, affecting both tumor tissue and healthy tissue. In order to overcome the drawbacks of 5-FU and enhance its therapeutic effectiveness against colorectal cancer, many studies have focused on designing new delivery systems to successfully deliver 5-FU to tumor sites. Liposomes have gained attention as a well-accepted nanocarrier for several chemotherapeutic agents. These amphipathic spherical vesicles consist of one or more phospholipid bilayers, showing promise for the drug delivery of both hydrophobic and hydrophilic components in addition to distinctive properties, such as biodegradability, biocompatibility, a low toxicity, and non-immunogenicity. Recent progress in liposomes has mainly focused on chemical and structural modifications to specifically target and activate therapeutic actions against cancer within the proximity of tumors. This review provides a comprehensive overview of both internal-stimuli-responsive liposomes, such as those activated by enzymes or pH, and external-stimuli-responsive liposomes, such as those activated by the application of a magnetic field, light, or temperature variations, for the site-specific delivery of 5-FU in colorectal cancer therapy, along with the future perspectives of these smart-delivery liposomes in colorectal cancer. In addition, this review critically highlights recent innovations in the literature on various types of stimuli-responsive liposomal formulations designed to be applied either exogenously or endogenously and that have great potential in delivering 5-FU to colorectal cancer sites.

Tumor-resident microbiota contributes to colorectal cancer liver metastasis by lactylation and immune modulation

The role of tumor-resident microbiota in modulating tumor immunity remains unclear. Here, we discovered an abundance of intra-tumoral bacteria, such us E.coli, residing and resulting in Colorectal cancer liver metastasis (CRLM). E.coli enhanced lactate production, which mediated M2 macrophage polarization by suppressing nuclear factor-κB -gene binding (NF-κB) signaling through retinoic acid-inducible gene 1 (RIG-I) lactylation. Lactylation of RIG-I suppressed recruitment of NF-κB to the Nlrp3 promoter in macrophages, thereby reducing its transcription. This loss of Nlrp3 affected the immunosuppressive activities of regulatory T cells (Tregs) and the antitumor activities of and CD8+ T cells. Small-molecule compound screening identified a RIG-I lactylation inhibitor that suppressed M2 polarization and sensitized CRLM to 5-fluorouracil (5-FU). Our findings suggest that tumor-resident microbiota may be a potential target for preventing and treating CRLM.

Camptothesome-based combination nanotherapeutic regimen for improved colorectal cancer immunochemotherapy

Camptothesome is a sphingomyelin-conjugated camptothecin (SM-CSS-CPT) nanovesicle that fortified the therapeutic delivery of CPT in diverse cancer types. To mitigate the Camptothesome-induced IDO1 negative feedback mechanism, we had co-encapsulated, indoximod (IND, IDO1 inhibitor) into Camptothesome using doxorubicin-derived IND (DOX-IND). To maximize the therapeutic potential of DOX-IND/Camptothesome, herein, we first dissected the synergistic drug ratio (DOX-IND/SM-CSS-CPT) via systematical in vitro screening. DOX-IND/Camptothesome with optimal drug ratio synchronized in vivo drug delivery with significantly higher tumor uptake compared to free drugs. This optimum DOX-IND/Camptothesome outperformed the combination of Camptothesome, Doxil and IND or other IDO1 inhibitors (BMS-986205 or epacadostat) in treating mice bearing late-stage MC38 tumors, and combination with immune checkpoint blockade (ICB) enabled it to eradicate 60 % of large tumors. Further, this optimized co-delivery Camptothesome beat Folfox and Folfiri, two first-line combination chemotherapies for colorectal cancer in antitumor efficacy and exhibited no side effects as compared to the severe systemic toxicities associated with Folfox and Folfiri. Finally, we demonstrated that the synergistic DOX-IND/Camptothesome was superior to the combined use of Onivyde + Doxil + IND in curbing the advanced orthotopic CT26-Luc tumors and eliminated 40 % tumors with complete metastasis remission when cooperated with ICB, eliciting stronger anti-CRC immune responses and greater reversal of immunosuppression. These results corroborated that with precise optimal synergistic drug ratio, the therapeutic potential of DOX-IND/Camptothesome can be fully unleased, which warrants further clinical investigation to benefit the cancer patients.

Design of lactoferrin functionalized carboxymethyl dextran coated egg albumin nanoconjugate for targeted delivery of capsaicin: Spectroscopic and cytotoxicity studies

The increased mortality rates associated with colorectal cancer highlight the pressing need for improving treatment approaches. While capsaicin (CAP) has shown promising anticancer activity, its efficacy is hampered due to low solubility, rapid metabolism, suboptimal bioavailability, and a short half-life. Therefore, this study aimed to prepare a lactoferrin-functionalized carboxymethyl dextran-coated egg albumin nanoconjugate (LF-CMD@CAP-EGA-NCs) for the targeted CAP delivery to enhance its potential for colorectal cancer therapy. Briefly, LF-CMD was synthesized through an esterification reaction involving LF as a receptor and CMD as a shell. Concurrently, CAP was incorporated into an EGA carrier using gelation and hydrophobic interactions. The subsequent production of LF-CMD@CAP-EGA-NCs was achieved through the Maillard reaction. Spectral characterizations confirmed the successful synthesis of smooth and spherical-shaped LF-CMD@CAP-EGA-NCs using LF-CMD and EGA-CAP nanoparticles, with high entrapment efficiency and satisfactory drug content. Furthermore, LF-CMD@CAP-EGA-NCs demonstrated a sustained release of CAP (76.52 ± 1.01 % in 24 h, R2 = 0.9966) in pH 5.8 buffer with anomalous transport (n = 0.68) owing to the shell of the CMD and EGA matrix. The nanoconjugate exhibited enhanced cytotoxicity in HCT116 and LoVo cell lines, which is attributed to the overexpression of LF receptors in colorectal HCT116 cells. Additionally, LF-CMD@CAP-EGA-NCs demonstrated excellent biocompatibility, as observed in the FHC-CRL-1831 cell line. In conclusion, LF-CMD@CAP-EGA-NCs can be considered as a promising approach for targeted delivery of CAP and other anticancer agents in colorectal cancer treatment.

Glycoproteomics-based liquid biopsy: translational outlook for colorectal cancer clinical management in Southeast Asia

Colorectal cancer (CRC) signifies a significant healthcare challenge in Southeast Asia. Despite advancements in screening approaches and treatment modalities, significant medical gaps remain, ranging from prevention and early diagnosis to determining targeted therapy and establishing personalized approaches to managing CRC. There is a need to expand more validated biomarkers in clinical practice. An advanced technique incorporating high-throughput mass spectrometry as a liquid biopsy to unravel a repertoire of glycoproteins and glycans would potentially drive the development of clinical tools for CRC screening, diagnosis and monitoring, and it can be further adapted to the existing standard-of-care procedure. Therefore this review offers a perspective on glycoproteomics-driven liquid biopsy and its potential integration into the clinical care of CRC in the southeast Asia region.

Hybrid-DIA: intelligent data acquisition integrates targeted and discovery proteomics to analyze phospho-signaling in single spheroids

Achieving sufficient coverage of regulatory phosphorylation sites by mass spectrometry (MS)-based phosphoproteomics for signaling pathway reconstitution is challenging, especially when analyzing tiny sample amounts. To address this, we present a hybrid data-independent acquisition (DIA) strategy (hybrid-DIA) that combines targeted and discovery proteomics through an Application Programming Interface (API) to dynamically intercalate DIA scans with accurate triggering of multiplexed tandem mass spectrometry (MSx) scans of predefined (phospho)peptide targets. By spiking-in heavy stable isotope labeled phosphopeptide standards covering seven major signaling pathways, we benchmark hybrid-DIA against state-of-the-art targeted MS methods (i.e., SureQuant) using EGF-stimulated HeLa cells and find the quantitative accuracy and sensitivity to be comparable while hybrid-DIA also profiles the global phosphoproteome. To demonstrate the robustness, sensitivity, and biomedical potential of hybrid-DIA, we profile chemotherapeutic agents in single colon carcinoma multicellular spheroids and evaluate the phospho-signaling difference of cancer cells in 2D vs 3D culture.

Intratumor heterogeneity and cell secretome promote chemotherapy resistance and progression of colorectal cancer

The major underlying cause for the high mortality rate in colorectal cancer (CRC) relies on its drug resistance, to which intratumor heterogeneity (ITH) contributes substantially. CRC tumors have been reported to comprise heterogeneous populations of cancer cells that can be grouped into 4 consensus molecular subtypes (CMS). However, the impact of inter-cellular interaction between these cellular states on the emergence of drug resistance and CRC progression remains elusive. Here, we explored the interaction between cell lines belonging to the CMS1 (HCT116 and LoVo) and the CMS4 (SW620 and MDST8) in a 3D coculture model, mimicking the ITH of CRC. The spatial distribution of each cell population showed that CMS1 cells had a preference to grow in the center of cocultured spheroids, while CMS4 cells localized at the periphery, in line with observations in tumors from CRC patients. Cocultures of CMS1 and CMS4 cells did not alter cell growth, but significantly sustained the survival of both CMS1 and CMS4 cells in response to the front-line chemotherapeutic agent 5-fluorouracil (5-FU). Mechanistically, the secretome of CMS1 cells exhibited a remarkable protective effect for CMS4 cells against 5-FU treatment, while promoting cellular invasion. Secreted metabolites may be responsible for these effects, as demonstrated by the existence of 5-FU induced metabolomic shifts, as well as by the experimental transfer of the metabolome between CMS1 and CMS4 cells. Overall, our results suggest that the interplay between CMS1 and CMS4 cells stimulates CRC progression and reduces the efficacy of chemotherapy.

Biological Activities of Miracle Berry Supercritical Extracts as Metabolic Regulators in Chronic Diseases

Synsepalum dulcificum (Richardella dulcifica) is a berry fruit from West Africa with the ability to convert the sour taste into a sweet taste, and for this reason, the fruit is also known as the "miracle berry" (MB). The red and bright berry is rich in terpenoids. The fruit's pulp and skin contain mainly phenolic compounds and flavonoids, which correlate with their antioxidant activity. Different polar extracts have been described to inhibit cell proliferation and transformation of cancer cell lines in vitro. In addition, MB has been shown to ameliorate insulin resistance in a preclinical model of diabetes induced by a chow diet enriched in fructose. Herein, we have compared the biological activities of three supercritical extracts obtained from the seed-a subproduct of the fruit-and one supercritical extract obtained from the pulp and the skin of MB. The four extracts have been characterized in terms of total polyphenols content. Moreover, the antioxidant, anti-inflammatory, hypo-lipidemic, and inhibition of colorectal cancer cell bioenergetics have been compared. Non-polar supercritical extracts from the seed are the ones with the highest effects on the inhibition of bioenergetic of colorectal (CRC) cancer cells. At the molecular level, the effects on cell bioenergetics seems to be related to the inhibition of main drivers of the de novo lipogenesis, such as the sterol regulatory element binding transcription factor (SREBF1) and downstream molecular targets fatty acid synthase (FASN) and stearoyl coenzyme desaturase 1 (SCD1). As metabolic reprograming is considered as one of the hallmarks of cancer, natural extracts from plants may provide complementary approaches in the treatment of cancer. Herein, for the first time, supercritical extracts from MB have been obtained, where the seed, a by-product of the fruit, seems to be rich in antitumor bioactive compounds. Based on these results, supercritical extracts from the seed merit further research to be proposed as co-adjuvants in the treatment of cancer.

Pharmacogenetics of Anticancer Drugs: Clinical Response and Toxicity

Cancer is the most challenging disease for medical professionals to treat. The factors underlying the complicated situation include anticancer drug-associated toxicity, non-specific response, low therapeutic window, variable treatment outcomes, development of drug resistance, treatment complications, and cancer recurrence. The remarkable advancement in biomedical sciences and genetics, over the past few decades, however, is changing the dire situation. The discovery of gene polymorphism, gene expression, biomarkers, particular molecular targets and pathways, and drug-metabolizing enzymes have paved the way for the development and provision of targeted and individualized anticancer treatment. Pharmacogenetics is the study of genetic factors having the potential to affect clinical responses and pharmacokinetic and pharmacodynamic behaviors of drugs. This chapter emphasizes pharmacogenetics of anticancer drugs and its applications in improving treatment outcomes, selectivity, toxicity of the drugs, and discovering and developing personalized anticancer drugs and genetic methods for prediction of drug response and toxicity.

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in small bowel adenocarcinoma with peritoneal metastasis: a systematic review

Objectives

Small bowel adenocarcinoma (SBA) with peritoneal metastasis (PM) is rare and despite treatment with systemic chemotherapy, the prognosis is poor. However, there is emerging evidence that cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) may offer a survival benefit over systemic therapy alone. This systematic review will assess the effectiveness of CRS-HIPEC for SBA-PM.

Content

Three databases were searched from inception to 11/10/21. Clinical outcomes were extracted and analysed.

Summary

A total of 164 cases of SBA-PM undergoing CRS-HIPEC were identified in 12 studies. The majority of patients had neoadjuvant chemotherapy (87/164, 53%) and complete cytoreduction (143/164, 87%) prior to HIPEC. The median overall survival was 9-32 months and 5-year survival ranged from 25 to 40%. Clavien-Dindo grade III/IV morbidity ranged between 19.1 and 50%, while overall mortality was low with only 3 treatment-related deaths.

Outlook

CRS-HIPEC has the potential to improve the overall survival in a highly selected group of SBA-PM patients, with 5-year survival rates comparable to those reported in colorectal peritoneal metastases. However, the expected survival benefits need to be balanced against the intrinsic risk of morbidity and mortality associated with the procedure. Further multicentre studies are required to assess the safety and feasibility of CRS-HIPEC in SBA-PM to guide best practice management for this rare disease.

CRISPR Cas9-mediated ablation of pyruvate carboxylase gene in colon cancer cell line HT-29 inhibits growth and migration, induces apoptosis and increases sensitivity to 5-fluorouracil and glutaminase inhibitor

Pyruvate carboxylase (PC) is an important anaplerotic enzyme that replenishes the tricarboxylic acid cycle (TCA) intermediates. It prevents the collapse of the TCA cycle upon its intermediates are removed during high anabolic demand. We have recently shown that overexpression of PC protein was associated with staging, metastasis and poor survival of colorectal cancer patients. Herein, we generated the PC knockout (PC KO) colon cancer cell lines, HT-29, by CRISPR-Cas9 technique, as a model to understand the role of this enzyme in colorectal cancer. The PC KO HT-29 cell lines had no detectable PC protein and did not show abnormal cellular or nuclear structures. However, PC KO HT-29 cells showed a 50-60% reduction in their growth rate and a 60-70% reduction in migration. The deficient growth phenotype of PC KO HT-29 cells was associated with apoptotic induction with no apparent cell cycle disruption following five days of growth. Down-regulation of key lipogenic enzymes, including acetyl-CoA carboxylase-1 and fatty acid synthase, was also associated with growth inhibition, suggesting that the de novo lipogenesis is impaired. Furthermore, PC KO HT-29 cells were 50% and 60% more sensitive to 5-fluorouracil and glutaminase inhibitor, CB-839, at their IC50 concentrations, respectively, following 48 h exposure. The increased cytotoxicity of CB-839 to PC KO HT-29 cells was associated with increased poly (ADP-ribose) polymerase cleavage. However, this was not observed with PC KO cells exposed to 5-fluorouracil, suggesting that PC KO HT-29 cells were prone to CB-839-induced apoptosis. Collectively, these findings indicate that ablation of PC expression in HT-29 cells disrupts the metabolic homeostasis of cells and inhibits proliferation and migration, accompanied by apoptotic induction. This study highlights the crucial role of PC in supporting the survival of HT-29 cells during exposure to chemotherapeutic drugs.

Ruthenium(II)-Cyclopentadienyl-Derived Complexes as New Emerging Anti-Colorectal Cancer Drugs

Colorectal cancer (CRC) is one of the most common malignancies and one of the leading causes of cancer-related death worldwide, urging the need for new and more efficient therapeutic approaches. Ruthenium complexes have emerged as attractive alternatives to traditional platinum-based compounds in the treatment of CRC. This work aims to evaluate anti-CRC properties, as well as to identify the mechanisms of action of ruthenium complexes with the general formula [Ru(η⁵-C₅H₄R)(PPh₃)(4,4′-R′-2,2′-bipyridine)][CF₃SO₃], where R = CH₃, CHO or CH₂OH and R′ = H, CH₃, CH₂OH, or dibiotin ester. The complexes (Ru 1–7) displayed high bioactivity, as shown by low IC₅₀ concentrations against CRC cells, namely, RKO and SW480. Four of the most promising ruthenium complexes (Ru 2, 5–7) were phenotypically characterized and were shown to inhibit cell viability by decreasing cell proliferation, inducing cell cycle arrest, and increasing apoptosis. These findings were in accordance with the inhibition of MEK/ERK and PI3K/AKT signaling pathways. Ruthenium complexes also led to a decrease in cellular clonogenic ability and cell migration, which was associated with the disruption of F-actin cytoskeleton integrity. Here, we demonstrated that ruthenium complexes, especially Ru7, have a high anticancer effect against CRC cells and are promising drugs to be used as a new therapeutical strategy for CRC treatment.

The Role of Conventional TACE (cTACE) and DEBIRI-TACE in Colorectal Cancer Liver Metastases

Colorectal cancer (CRC) is one of the most common tumor entities worldwide and a common cause of cancer-associated death. Colorectal cancer liver metastases (CRLM) thereby constitute a severe life-limiting factor. The therapy of CRLM presents a major challenge and surgical resection as well as systemic chemotherapy remain the first-line treatment options. Over the years several locoregional, vascular- and image-based treatments offered by interventional radiologists have emerged when conventional therapies fail, or metastases recurrence occurs. Among such options is the conventional/traditional transarterial chemoembolization (cTACE) by local injection of a combination of chemotherapeutic- and embolic-agents. A similar treatment is the more recent irinotecan-loaded drug-eluting beads TACE (DEBIRI-TACE), which are administered using the same approach. Numerous studies have shown that these different types of chemoembolization can be applied in different clinical settings safely. Furthermore, such treatments can also be combined with other local or systemic therapies. Unfortunately, due to the incoherent patient populations of studies investigating TACE in CRLM, critics state that the definite evidence supporting positive patient outcomes is still lacking. In the following article we review studies on conventional and DEBIRI-TACE. Although highly dependent on the clinical setting, prior therapies and generally the study population, cTACE and DEBIRI-TACE show comparable results. We present the most representative studies on the different chemoembolization procedures and compare the results. Although there is compelling evidence for both approaches, further studies are necessary to determine which patients profit most from these therapies. In conclusion, we determine TACE to be a viable option in CRLM in different clinical settings. Nevertheless, a multidisciplinary approach is desired to offer patients the best possible care.

Metformin and ICG-001 Act Synergistically to Abrogate Cancer Stem Cells-Mediated Chemoresistance in Colorectal Cancer by Promoting Apoptosis and Autophagy

Simple Summary

Colorectal cancer (CRC) is one of the most frequently diagnosed and lethal malignancies. The majority of CRC patients experience disease relapse after the primary curative treatment strategy of surgery followed by 5FU-based chemotherapy. The presence of cancer stem-like cells (CSCs) is considered to be one of the contributing factors to therapy resistance and disease relapse in CRC. Previous studies implicated the role of the Wnt signaling pathway in the maintenance of the CSC phenotype. Therefore, in this study we explored a novel therapeutic strategy using metformin along with ICG-001, a Wnt signaling inhibitor, to abrogate CSC-mediated chemoresistance in CRC. We observed that metformin and ICG-001 abrogate stemness in a synergistic manner by promoting autophagy and apoptosis in 5FU-resistant CRC cells as well as in CRC patient-derived tumor organoids. Hence, metformin and ICG-001 can be used as part of a therapeutic strategy to overcome 5FU-mediated therapeutic resistance in CRC.

Abstract

Colorectal cancer (CRC) remains the third most frequently diagnosed cancer in the United States. The current treatment regimens for CRC include surgery followed by 5FU-based chemotherapy. Cancer stem-like cells (CSCs) have been implicated in 5FU-mediated chemoresistance, which leads to poor prognosis. In this study, we used metformin along with ICG-001, a Wnt signaling inhibitor, to abrogate CSC-mediated chemoresistance in CRC. We observed that 5FU-resistant (5FUR) CRC cells exhibited increased expression of CSC markers and enhanced spheroid formation. Genome-wide transcriptomic profiling analysis revealed that Wnt signaling, colorectal cancer metastasis signaling, etc., were enriched in 5FUR CRC cells. Accordingly, selective targeting of Wnt signaling using ICG-001 along with metformin abrogated CSC-mediated chemoresistance by decreasing the expression of CSC markers and promoting autophagy and apoptosis in a synergistic manner. We also observed that metformin and ICG-001 exhibited anti-tumor activity in CRC patient-derived tumor organoids. In conclusion, our study highlights that metformin and ICG-001 act synergistically and can be used as part of a therapeutic strategy to overcome 5FU-mediated therapeutic resistance in CRC.

Curcumin Loaded Nanocarriers with Varying Charges Augmented with Electroporation Designed for Colon Cancer Therapy

(1) Background: The size and surface charge are the most significant parameters of nanocarriers that determine their efficiency and potential application. The poor cell uptake of encapsulated drugs is the main limitation in anticancer treatment. The well-defined properties of nanocarriers will enable to target specific tissue and deliver an active cargo. (2) Methods: In the current study, poly(D,L -lactide) (PLA) nanocarriers loaded with curcumin (CUR) and differing surface charge were evaluated for transport efficacy in combination with electroporation (EP) in dependence on the type of cells. The obtained CUR-loaded nanoparticles with diameters ranging from 195 to 334 nm (derived from dynamic light scattering (DLS)) were characterized by atomic force microscopy (AFM) (morphology and shape) and Doppler electrophoresis (ζ-potential) as well as UV-vis spectroscopy (CUR encapsulation efficiency (about 90%) and photobleaching rate). The drug delivery properties of the obtained PLA nanocarriers enhanced by electroporation were assessed in human colon cancer cells (LoVo), excitable normal rat muscle cells (L6), and free of voltage-gated ion channels cells (CHO-K1). CLSM studies, viability, and ROS release were performed to determine the biological effects of nanocarriers. (3) Results: The highest photodynamic activity indicated anionic nanocarriers (1a) stabilized by C₁₂(COONa)₂ surfactant. Nanocarriers were cytotoxic for LoVo cells and less cytotoxic for normal cells. ROS release increased in cancer cells with the increasing electric field intensity, irradiation, and time after EP. Muscle L6 cells were less sensitive to electric pulses. (4) Conclusions: EP stimulation for CUR-PLA nanocarriers transport was considered to improve the regulated and more effective delivery of nanosystems differing in surface charge.

Regulation of signal transduction pathways in colorectal cancer: implications for therapeutic resistance

Resistance to anti-cancer treatments is a critical and widespread health issue that has brought serious impacts on lives, the economy and public policies. Mounting research has suggested that a selected spectrum of patients with advanced colorectal cancer (CRC) tend to respond poorly to both chemotherapeutic and targeted therapeutic regimens. Drug resistance in tumours can occur in an intrinsic or acquired manner, rendering cancer cells insensitive to the treatment of anti-cancer therapies. Multiple factors have been associated with drug resistance. The most well-established factors are the emergence of cancer stem cell-like properties and overexpression of ABC transporters that mediate drug efflux. Besides, there is emerging evidence that signalling pathways that modulate cell survival and drug metabolism play major roles in the maintenance of multidrug resistance in CRC. This article reviews drug resistance in CRC as a result of alterations in the MAPK, PI3K/PKB, Wnt/β-catenin and Notch pathways.

Combinatorial Strategies to Target Molecular and Signaling Pathways to Disarm Cancer Stem Cells

Cancer is an urgent public health issue with a very huge number of cases all over the world expected to increase by 2040. Despite improved diagnosis and therapeutic protocols, it remains the main leading cause of death in the world. Cancer stem cells (CSCs) constitute a tumor subpopulation defined by ability to self-renewal and to generate the heterogeneous and differentiated cell lineages that form the tumor bulk. These cells represent a major concern in cancer treatment due to resistance to conventional protocols of radiotherapy, chemotherapy and molecular targeted therapy. In fact, although partial or complete tumor regression can be achieved in patients, these responses are often followed by cancer relapse due to the expansion of CSCs population. The aberrant activation of developmental and oncogenic signaling pathways plays a relevant role in promoting CSCs therapy resistance. Although several targeted approaches relying on monotherapy have been developed to affect these pathways, they have shown limited efficacy. Therefore, an urgent need to design alternative combinatorial strategies to replace conventional regimens exists. This review summarizes the preclinical studies which provide a proof of concept of therapeutic efficacy of combinatorial approaches targeting the CSCs.

Racial Disparities in Treatment for Rectal Cancer at Minority-Serving Hospitals

BACKGROUND

Racial disparities exist in patients with rectal cancer with respect to both treatment and survival. Minority-serving hospitals (MSHs) provide healthcare to a disproportionately large percent of minority patients in the USA. We examined the effects of rectal cancer treatment at MSH to understand drivers of these disparities.

METHODS

The NCDB was queried (2004-2015), and patients diagnosed with stage II or III rectal adenocarcinoma were identified. Racial case mix distribution was calculated at the institutional level, and MSHs were defined as those within the top decile of Black and Hispanic patients. Logistic regression was used to identify predictors of receipt of standard of care treatment. Survival was assessed using the Kaplan-Meier method, and Cox proportional hazards models were used to evaluate adjusted risk of death. Analyses were clustered by facility.

RESULTS

A total of 68,842 patients met the inclusion criteria. Of these patients, 63,242 (91.9%) were treated at non-MSH, and 5600 (8.1%) were treated at MSH. In multivariable analysis, treatment at MSH (OR 0.70 95%CI 0.61-0.80 p < 0.001) and Black race (OR 0.75 95%CI 0.70-0.81 p < 0.001) were associated with significantly lower odds of receiving standard of care. In adjusted analysis, Black patients had a significantly higher risk of mortality (HR 1.20 95%CI 1.14-1.26 p < 0.001).

CONCLUSIONS

Treatment at MSH institutions and Black race were associated with significantly decreased odds of receipt of recommended standard therapy for locally advanced rectal adenocarcinoma. Survival was worse for Black patients compared to White patients despite adjustment for receipt of standard of care.

High expression of DNA damage-inducible transcript 4 (DDIT4) is associated with advanced pathological features in the patients with colorectal cancer

DNA damage-inducible transcript 4 (DDIT4) is induced in various cellular stress conditions. This study was conducted to investigate expression and prognostic significance of DDIT4 protein as a biomarker in the patients with colorectal cancer (CRC). PPI network and KEGG pathway analysis were applied to identify hub genes among obtained differentially expressed genes in CRC tissues from three GEO Series. In clinical, expression of DDIT4 as one of hub genes in three subcellular locations was evaluated in 198 CRC tissues using immunohistochemistry method on tissue microarrays. The association between DDIT4 expression and clinicopathological features as well as survival outcomes were analyzed. Results of bioinformatics analysis indicated 14 hub genes enriched in significant pathways according to KEGG pathways analysis among which DDIT4 was selected to evaluate CRC tissues. Overexpression of nuclear DDIT4 protein was found in CRC tissues compared to adjacent normal tissues (P = 0.003). Furthermore, higher nuclear expression of DDIT4 was found to be significantly associated with the reduced tumor differentiation and advanced TNM stages (all, P = 0.009). No significant association was observed between survival outcomes and nuclear expression of DDIT4 in CRC cases. Our findings indicated higher nuclear expression of DDIT4 was significantly associated with more aggressive tumor behavior and more advanced stage of disease in the patients with CRC.

Development and validation of a novel miRNA classifier as a prognostic signature for stage II/III colorectal cancer

Background

The TNM staging remains the gold standard for determining the prognosis of patients with colorectal cancer (CRC), which is inadequate at identifying the subset of high-risk stage II and III patients that have a high potential of developing tumor recurrence and may experience death. Emerging evidence indicates that not only microRNAs (miRNAs) play important functional role in CRC development but may serve as important disease biomarkers. In this study we aimed to develop a miRNA-based classifier as a prognostic signature for improving the clinical outcome of patients with stage II/III CRC.

Methods

We performed a systematic and comprehensive discovery step to identify differentially expressed miRNAs in CRC. We subsequently determined the prognostic relevance of these miRNAs in stage II/III patients using qRT-PCR and developed a miRNA-based classifier for predicting disease-free survival (DFS) in a clinical cohort (n=186).

Results

Based upon miRNA expression profiling studies, we identified a panel of 10 miRNAs which are consistently differentially expressed in CRC vs. normal tissues. By using cox proportional hazard models, we then developed 6-miRNA-classifier (miR-183, -20a, -21, -195, -139 and -20a) to predict prognosis in clinical cohort, that had significantly superior predictive performance compared to other clinicopathological factors, and could successfully identify high-risk stage II and III CRC patients with poor prognosis [hazard ratio (HR) =2.16; P=0.0048]. In a multivariate analysis, this miRNA-based classifier emerged as an independent prognostic signature for poor DFS.

Conclusions

Our miRNA-based classifier is a reliable predictive tool for determining prognosis in patents with stage II/III CRC, and might be able to identify high-risk patients that are candidates for more targeted personalized clinical management and surveillance.

Oral drugs in the treatment of metastatic colorectal cancer

Colorectal cancer (CRC) is one of the most common forms of cancer, with an estimated 1.36 million new cases and almost 700,000 deaths annually. Approximately 21% of patients with CRC have metastatic disease at diagnosis. The objective of this article is to review the literature on the efficacy and safety of oral drugs available for the treatment of metastatic colorectal cancer (mCRC). Several such drugs have been developed, and fluoropyrimidines are the backbone of chemotherapy in this indication. They exert their antitumour activity by disrupting the synthesis and function of DNA and RNA. Oral fluoropyrimidines include prodrugs capecitabine, tegafur, eniluracil/5-fluorouracil, tegafur/uracil, tegafur/gimeracil/oteracil and trifluridine/tipiracil (FTD/TPI). Oral drugs offer several advantages over injectable formulations, including convenience, flexibility, avoidance of injection-related adverse events (AEs) and, in some circumstances, lower costs. However, oral drugs may not be suitable for patients with gastrointestinal obstruction or malabsorption, they may result in reduced treatment adherence and should not be co-administered with drugs that interfere with absorption or hepatic metabolism. Oral fluoropyrimidines such as capecitabine, as monotherapy or in combination with oxaliplatin, irinotecan or bevacizumab, are as effective as intravenous 5-fluorouracil (5-FU) in first-line treatment of mCRC. Other oral fluoropyrimidines, such as FTD/TPI, are effective in patients with mCRC who are refractory, intolerant or ineligible for 5-FU. In addition, oral fluoropyrimidines are used in adjuvant treatment of mCRC. Regorafenib is an oral multikinase inhibitor used in patients in whom several previous lines of therapy have failed. Frequent AEs associated with oral drugs used in the treatment of CRC include hand-foot syndrome and gastrointestinal and haematological toxicities.

Dietary Intake as Determinant Nongenetic Factors to Colorectal Cancer Incidence and Staging Progression: A Study in South Sulawesi Population, Indonesia

Reports from various population-based studies indicate that the incidence of colorectal cancer may be strongly affected by dietary patterns of the respective populations. The nature of dietary patterns of specific Indonesia population on the risk of colorectal cancer might differ from previously published data with the global population. Therefore, we conducted a study where the dietary pattern in colorectal cancer patient cohorts was compared to age- and population-matched control. We documented 89 colorectal cancer cases and among 173 individuals from the South Sulawesi population. A series of logistic regression and Fisher's exact tests were utilized to test associations of dietary intakes and colorectal cancer risk as well as colorectal cancer staging. Our data demonstrate that vegetable (p-value = 8.70 × 10^-26, OR = 0.49) and fruit (p-value = 7.59x10^-5, OR = 0.70) intakes are associated with the reduced risk of colorectal cancer incidence. Conversely, acidic food, reheated food, meat, spicy food, and alcohol are associated with the increment case of cancer. Moreover, meat intake (p-value < 0.01) shows a significant association with cancer staging progression. Common dietary pattern is a determinant aspect to the colorectal cancer incidence as well as its staging progression.

5-FU promotes stemness of colorectal cancer via p53-mediated WNT/β-catenin pathway activation

5-Fluorouracil (5-FU) remains the first-line treatment for colorectal cancer (CRC). Although 5-FU initially de-bulks the tumor mass, recurrence after chemotherapy is the barrier to effective clinical outcomes for CRC patients. Here, we demonstrate that p53 promotes WNT3 transcription, leading to activation of the WNT/β-catenin pathway in Apc^Min/+/Lgr5^EGFP mice, CRC patient-derived tumor organoids (PDTOs) and patient-derived tumor cells (PDCs). Through this regulation, 5-FU induces activation and enrichment of cancer stem cells (CSCs) in the residual tumors, contributing to recurrence after treatment. Combinatorial treatment of a WNT inhibitor and 5-FU effectively suppresses the CSCs and reduces tumor regrowth after discontinuation of treatment. These findings indicate p53 as a critical mediator of 5-FU-induced CSC activation via the WNT/β-catenin signaling pathway and highlight the significance of combinatorial treatment of WNT inhibitor and 5-FU as a compelling therapeutic strategy to improve the poor outcomes of current 5-FU-based therapies for CRC patients.

Immunological Features with DNA Microsatellite Alterations in Patients with Colorectal Cancer

Competent human DNA mismatch repair (MMR) corrects DNA polymerase mistakes made during cell replication to maintain complete DNA fidelity in daughter cells; faulty DNA MMR occurs in the setting of inflammation and neoplasia, creating base substitutions (e.g. point mutations) and frameshift mutations at DNA microsatellite sequences in progeny cells. Frameshift mutations at DNA microsatellite sequences are a detected biomarker termed microsatellite instability (MSI) for human disease, as this marker can prognosticate and determine therapeutic approaches for patients with cancer. There are two types of MSI: MSI-High (MSI-H), defined by frameshifts at mono- and di-nucleotide microsatellite sequences, and elevated microsatellite alterations at selected tetranucleotide repeats or EMAST, defined by frameshifts in di- and tetranucleotide microsatellite sequences but not mononucleotide sequences. Patients with colorectal cancers (CRCs) manifesting MSI-H demonstrate improved survival over patients without an MSI-H tumor, driven by the generation of immunogenic neoantigens caused by novel truncated proteins from genes whose sequences contain coding microsatellites; these patients' tumors contain hundreds of somatic mutations, and show responsiveness to treatment with immune checkpoint inhibitors. Patients with CRCs manifesting EMAST demonstrate poor survival over patients without an EMAST tumor, and may be driven by a more dominant defect in double strand break repair attributed to the MMR protein MSH3 over its frameshift correcting function; these patients' tumors often have a component of inflammation (and are also termed inflammation-associated microsatellite alterations) and show less somatic mutations and lack coding mononucleotide frameshift mutations that seem to generate the neoantigens seen in the majority of MSI-H tumors. Overall, both types of MSI are biomarkers that can prognosticate patients with CRC, can be tested for simultaneously in marker panels, and informs the approach to specific therapy including immunotherapy for their cancers.

TaqI and ApaI Variants of Vitamin D Receptor Gene Increase the Risk of Colorectal Cancer in a Saudi Population

Background:

Polymorphisms in the gene encoding the vitamin D receptor (VDR) affect the protective role of vitamin D against many types of cancers, including colorectal cancer (CRC).

Objective:

The objective of this study was to assess the effect of four major polymorphisms of the VDR gene (ApaI, TaqI, BsmI and FokI) on the risk of CRC in a Saudi population.

Materials and Methods:

This case–control study recruited 132 CRC patients from the oncology clinics at King Abdulaziz University Hospital and 124 healthy controls from the blood bank at King Fahad General Hospital, Jeddah, Saudi Arabia, between September 2017 and August 2018. All participants were Saudis and aged 20–80 years. Genomic DNA samples were extracted from the peripheral blood cells and amplified with polymerase chain reaction. The resulting fragments were digested with different endonucleases to reveal the genotypes using the restriction fragment length polymorphism technique. The genotype distribution and allele frequency, odds ratio (OR), risk ratio (RR) and P values were determined with contingency table analysis following Hardy–Weinberg equilibrium equation.

Results:

For the ApaI single-nucleotide polymorphism (SNP) (rs7975232), only the heterozygous (Aa) genotype increased the risk of CRC (OR = 3.4, RR = 2.3, and P < 0.0001), whereas the TaqI SNP (rs731236) carriers with either the heterozygous (Tt) or homozygous (tt) genotype displayed an increased risk for the disease (OR = 6.18, RR = 4, P < 0.0001; OR = 3, RR = 2.4, P = 0.02, respectively). In contrast, heterozygous (Bb) and homozygous (bb) carriers of the BsmI SNP (rs1544410) had significantly lower risk for CRC (P < 0.0001). Finally, for the FokI SNP (rs2228570), there was no association with CRC risk.

Conclusion:

This study found that VDR SNPs ApaI and TaqI increase the risk of CRC, whereas BsmI reduces the risk of CRC in the selected Saudi population. Therefore, ApaI and TaqI SNPs could potentially be used as a diagnostic biomarker for CRC. However, the molecular mechanisms by which these variants increase or decrease the risk of CRC need to be investigated.

Synergistic antitumor effect of 5-fluorouracil with the novel LSD1 inhibitor ZY0511 in colorectal cancer

Background

Lysine-specific histone demethylase 1 (LSD1) is a potential target of cancer therapy. In the present study, we aimed to investigate the combined antitumor activity of a novel LSD1 inhibitor (ZY0511) with 5-fluorouracil (5-FU) and elucidate the underlying mechanism in colorectal cancer (CRC).

Methods

We evaluated LSD1 expression in CRC tissues from patients who received 5-FU treatment. The synergistic antitumor effect of 5-FU with ZY0511 against human CRC cells was detected both in vitro and in vivo. The underlying mechanism was explored based on mRNA sequencing (mRNA-seq) technology.

Results

Overexpression of LSD1 was observed in human CRC tissues, and correlated with CRC development and 5-FU resistance. ZY0511, a novel LSD1 inhibitor, effectively inhibited CRC cells proliferation, both in vitro and in vivo. Notably, the combination of ZY0511 and 5-FU synergistically reduced CRC cells viability and migration in vitro. It also suppressed Wnt/β-catenin signaling and DNA synthesis pathways, which finally induced apoptosis of CRC cells. In addition, the combination of ZY0511 with 5-FU significantly reduced CRC xenograft tumor growth, along with lung and liver metastases in vivo.

Conclusions

Our findings identify LSD1 as a potential marker for 5-FU resistance in CRC. ZY0511 is a promising candidate for CRC therapy as it potentiates 5-FU anticancer effects, thereby providing a new combinatorial strategy for treating CRC.

Sociodemographic predictors of surgery refusal in patients with stage I-III colon cancer

BACKGROUND AND OBJECTIVES

Over 104 000 cases of colon cancer are estimated to be diagnosed in 2020. Surgical resection is a critical part of colon cancer treatment and adequate resection impacts prognosis. However, some patients refuse potentially curative surgery. We aimed to identify the rate and predictors of surgery refusal among patients with colon cancer.

METHODS

The National Cancer Database (2004-2015) was queried for patients diagnosed with stage I-III colonic adenocarcinoma. Sociodemographic factors, clinical features, and treatment facility characteristics were collected. Patients who underwent surgery with curative intent were compared to those who refused surgery. Multivariable analysis was used to identify factors associated with surgery refusal. Adjusted survival analysis was performed on propensity-matched cohorts.

RESULTS

A total of 151 020 patients were included and 1071 (0.71%) refused surgery. In multivariable analysis older age, Black race, higher Charlson comorbidity score, Medicaid, Medicare, or lack of insurance were predictive of refusing surgery. After propensity matching, there was a significant difference in 5-year survival for patients who refused surgery vs those who underwent surgery (P < .001).

CONCLUSIONS

There are racial and socioeconomic disparities in the refusal of surgery for colon cancer. Further studies are needed to better understand the drivers behind differences in refusing curative surgery for colon cancer.

GATA6 enhances the stemness of human colon cancer cells by creating a metabolic symbiosis through upregulating LRH-1 expression

Cancer stem cells play critical roles in tumor initiation, progression, and relapse. Since we previously found that GATA6 promotes the stemness in HCT‐116 and HT‐29 human colorectal cancer (CRC) cells, we aimed to identify the downstream mediator(s) of the stemness‐stimulating effect of GATA6 herein. LRH‐1 was found as a direct target of GATA6 and its upregulation promoted the stemness in both HCT‐116 and HT‐29 cells. Subsequently, hypoxia‐inducible factor‐1α (HIF‐1α) was identified as a direct target of LRH‐1 and its expression level and activity were significantly elevated in the LRH‐1‐overexpressing clones established from the aforementioned two CRC lines. Accordingly, the expression levels of several HIF‐1α targets were also markedly increased, resulting in a stronger glycolysis associated with dramatic elevations of the lactate levels in these cells. Strikingly, higher mitochondrial activities were also found in these clones which might be attributed to the increase of PGC‐1α stimulated by the lactate uptaken through the upregulated MCT‐1. Finally, significant increases in the self‐renewal ability, intracellular radical oxygen species levels and mitochondrial mass were detected in the CD133⁺/CD44⁺ subpopulations isolated from CRC cells regardless of their LRH‐1 expression levels. Together, our results suggest a novel metabolic symbiosis between different colorectal cancer stem cell subpopulations critical for maintaining their mutual stemness.

Discovery of N-phenyl-(2,4-dihydroxypyrimidine-5-sulfonamido) phenylurea-based thymidylate synthase (TS) inhibitor as a novel multi-effects antitumor drugs with minimal toxicity

Thymidylate synthase (TS) is a hot target for tumor chemotherapy, and its inhibitors are an essential direction for anti-tumor drug research. To our knowledge, currently, there are no reported thymidylate synthase inhibitors that could inhibit cancer cell migration. Therefore, for optimal therapeutic purposes, combines our previous reports and findings, we hope to obtain a multi-effects inhibitor. This study according to the principle of flattening we designed and synthesized 18 of N-phenyl-(2,4-dihydroxypyrimidine-5-sulfonamido)phenyl urea derivatives as multi-effects inhibitors. The biological evaluation results showed that target compounds could significantly inhibit the hTS enzyme, BRaf kinase and EGFR kinase activity in vitro, and most of the compounds had excellent anti-cell viability for six cancer cell lines. Notably, the candidate compound L14e (IC₅₀ = 0.67 μM) had the superior anti-cell viability and safety to A549 and H460 cells compared with pemetrexed. Further studies had shown that L14e could cause G1/S phase arrest then induce intrinsic apoptosis. Transwell, western blot, and tube formation results proved that L14e could inhibit the activation of the EGFR signaling pathway, then ultimately achieve the purpose of inhibiting cancer cell migration and angiogenesis in cancer tissues. Furthermore, in vivo pharmacology evaluations of L14e showed significant antitumor activity in A549 cells xenografts with minimal toxicity. All of these results demonstrated that the L14e has the potential for drug discovery as a multi-effects inhibitor and provides a new reference for clinical treatment of non-small cell lung cancer.

Systemic chemotherapy and survival in patients with metastatic low-grade appendiceal mucinous adenocarcinoma

BACKGROUND

Appendiceal cancer is a rare malignancy that exhibits a wide range of histology and treatment response. Given the rarity and heterogeneous nature of the disease, it has been difficult to define optimal treatment strategies. Our goal is to examine the association between use of systemic chemotherapy and survival in patients with metastatic low-grade mucinous appendiceal adenocarcinoma.

METHODS

The National Cancer Database (2004-2015) was queried, and patients with mucinous, grade 1, stage IV appendiceal adenocarcinoma were identified. The Kaplan-Meier method was used to calculate survival, and a Cox regression model was used to identify predictors of survival.

RESULTS

Six hundred and thirty-nine patients were identified. Five-year overall survival (OS) for patients undergoing no chemotherapy vs chemotherapy was 52.9% and 61.3%, respectively. After adjusting with Cox proportional hazards model, chemotherapy was not associated with OS (HR:1.1, 95% CI:0.82-1.40, P = 0.61). Patients who underwent surgical resection (HR:0.40, 95% CI:0.28-0.57, P < .001) or were female (HR:0.61, 95% CI:0.5-0.8, P < .001) had improved survival in adjusted analysis.

CONCLUSIONS

There is no association between undergoing chemotherapy and OS in this cohort of patients with stage IV low-grade mucinous appendiceal adenocarcinoma. Development of national treatment guidelines is urgently needed for more consistency in the management of patients with appendiceal cancers.

Prevalence, Safety and Long-Term Retention Rates of Biologics in Hong Kong from 2001 to 2015

BACKGROUND

Biologic agents were initially introduced as treatment for rheumatoid arthritis (RA) but have since been used for other medical conditions. As new biologics become increasingly widespread in treatment regimens, it is important to understand their safety and utilization in the post-marketing context.

PURPOSE

The aim of this study was to investigate long-term prescribing patterns and the safety of biologics in real clinical settings in Hong Kong.

METHODS

This was a population-based drug utilization study in Hong Kong using a territory-wide electronic medical database Clinical Data Analysis and Reporting System (CDARS). Patients who received biologic treatments from 2001 to 2015 were identified and their corresponding demographic and clinical details retrieved from CDARS. The annual prevalence of biologic prescriptions, the long-term retention rates and incidence rates of infections associated with biologic treatments were evaluated.

RESULTS

A total of 30,298 patients (male: 44%) prescribed biologic treatments were identified from CDARS from 2001 to 2015. The annual prevalence of biologic prescriptions increased from 0.1 to 16.1 per 100 persons for both sexes. Infliximab had the highest first-year retention rate of 95.6% among all biologics and continuously attained the highest retention rate from second to fifth year. The overall incidence rate of serious infections was less than five per 100 person-years. Specifically, the incidence rates of tuberculosis, upper and lower respiratory infections and herpes zoster were 0.52, 3.24, 4.99 and 1.01 per 100 person-years, respectively.

CONCLUSION

This population-based study revealed an increasing prevalence of biologic prescribing. Results from the study described the long-term retention rates and incidence rates of serious infections of biologic treatments for all indications, and confirmed the safety of biologic treatments. Since this study provides an overview of all biologic utilization, further studies on cost effectiveness, safety and compliance of treatment in different patient groups are still warranted.

Rethinking Alkylating(-Like) Agents for Solid Tumor Management

Although old molecules, alkylating agents and platinum derivatives are still widely used in the treatment of various solid tumors. However, systemic toxicity and cellular resistance mechanisms impede their efficacy. Innovative strategies, including local administration, optimization of treatment schedule/dosage, synergistic combinations, and the encapsulation of bioactive molecules in smart, multifunctional drug delivery systems, have shown promising results in potentiating anticancer activity while circumventing such hurdles. Furthermore, questioning of the old paradigm according to which nuclear DNA is the critical target of their anticancer activity has shed light on subcellular alternative and neglected targets that obviously participate in the mediation of cytotoxicity or resistance. Thus, rethinking of the use of these pivotal antineoplastic agents appears critical to improve clinical outcomes in the management of solid tumors.

Silibinin, A Natural Blend In Polytherapy Formulation For Targeting Cd44v6 Expressing Colon Cancer Stem Cells

Colon cancer stem cells have been attributed to poor prognosis, therapeutic resistance and aggressive nature of the malignancy. Recent reports associated CD44v6 expression with relapse, metastasis and reduced 5-year survival of colon cancer patients, thereby making it a potential therapeutic target. Thus, in this study, comprehensive prediction and screening of CD44v6 against 1674 lead compounds was conducted. Silibinin was identified as a potential compound targeting CD44v6. Inorder to substantiate these findings, the cytotoxic effect of 5FU, Silibinin and 5FU+ Silibinin was assessed on human colon carcinoma cell line HCT116 derived CD44+ subpopulation. 5FU+ Silibinin inhibited cell proliferation of CD44+ subpopulation at lower concentration than Silibinin standalone. Further, corresponding to CD44v6 knockdown cells, 5FU+ Silibinin treatment significantly decreased CD44v6, Nanog, CTNNB1 and CDKN2A expression whereas increased E-cadherin expression in HCT116 derived CD44+ cells. Moreover, synergistic effect of these drugs suppressed sphere formation, inhibited cell migration, triggered PARP cleavage and perturbation in mitochondrial membrane potential, thereby activating intrinsic apoptotic pathways and induced autophagic cell death. Importantly, 5FU+ Silibinin could inhibit PI3K/MAPK dual activation and arrest the cell cycle at G0/G1 phase. Thus, our study suggests that inhibition of CD44v6 attenuates stemness of colon cancer stem cells and holds a prospect of potent therapeutic target.

Computational analysis of mRNA expression profiles identifies a novel triple-biomarker model as prognostic predictor of stage II and III colorectal adenocarcinoma patients

Introduction

Although remarkable progress has been made to determine the prognosis of patients with colorectal cancer (CRC), it is inadequate to identify the subset of high-risk TNM stage II and stage III patients that have a high potential of developing tumor recurrence and may experience death. In this study, we aimed to develop biomarkers as a prognostic signature for the clinical outcome of CRC patients with stage II and stage III.

Materials and methods

We performed a systematic and comprehensive discovery step to identify recurrence-associated genes in CRC patients through publicly available GSE41258 (n=253) and GSE17536 (n=107) datasets. We subsequently determined the prognostic relevance of candidate genes in stage II and III patients and developed a triple-biomarker for predicting RFS in GSE17536, which was later validated in an independent cohort GSE33113 dataset (n=90).

Results

Based upon mRNA expression profiling studies, we identified 45 genes which differentially expressed in recurrent vs non-recurrent CRC patients. By using Cox proportional hazard models, we then developed a triple-marker model (THBS2, SERPINE1, and FN1) to predict prognosis in GSE17536, which successfully identified poor prognosis in stage II and stage III, particularly high-risk stage II CRC patients.

Discussion

Notably, we found that our triple-marker model once again predicted recurrence in stage II patients in GSE33113. Kaplan-Meier survival analysis demonstrated that patients with high scores have a poor outcome compared to those with low scores. Our triple-marker model is a reliable predictive tool for determining prognosis in CRC patients with stage II and stage III, and might be able to identify high-risk patients that are candidates for more targeted personalized clinical management and surveillance.

Trifluridine/tipiracil: an emerging strategy for the management of gastrointestinal cancers

Fluoropyrimidines are currently the backbone of treatment for gastrointestinal (GI) cancers but development of resistance to these agents remains a major problem. Trifluridine/tipiracil is an oral chemotherapeutic agent recently approved for third-line treatment of chemorefractory metastatic colorectal cancer. This article reviews the clinical value of trifluridine/tipiracil as a monotherapy, including recent trials in GI cancers, and the potential benefit of combining it with other agents in patients with GI cancers, including the preclinical rationale for combination therapy and recently completed and ongoing clinical trials. Data gathered so far suggest that trifluridine/tipiracil has the potential to form the chemotherapeutic backbone in the continuum of care for GI cancers in the future.

The Determinants of Palliative Care Use in Patients With Colorectal Cancer: A National Study

BACKGROUND

Palliative care is associated with improved survival and quality of life, but its use among patients with colorectal cancer varies nationwide and the determinants of those variations are not clear.

OBJECTIVE

To determine the factors associated with palliative care use among patients who died of colorectal cancer.

METHODS

Deceased patients treated for colorectal cancer (2004-2013) were identified within the National Cancer Database. Multivariable logistic regression was used to evaluate patient and institutional characteristics associated with palliative care use. Patients were classified based on their length of survival (<6 months, 6-24 months, and 24+ months) to provide timing context.

RESULTS

A total of 287 923 patients were analyzed. Overall, 4.3% of the patients received palliative care. Patients who received palliative care were more likely to be younger, recently diagnosed, treated at academic hospitals, and have stage IV disease. Patients living in Mountain and Pacific regions had higher odds of palliative care receipt than those in the East Coast. Patients without insurance had higher odds of palliative care if they survived <24 months. Insurance coverage through Medicaid was associated with increased palliative care use among patients who survived 6 to 24 months. Patients who survived <6 months and lived >9 miles from the institution received more palliative care.

CONCLUSION

Palliative care use among patients with colorectal cancer is associated with a younger age, a more recent year of diagnosis, insurance status, academic hospitals, and living in Mountain and Pacific regions.

Novel 1,3,4-thiadiazoles inhibit colorectal cancer via blockade of IL-6/COX-2 mediated JAK2/STAT3 signals as evidenced through data-based mathematical modeling

We attempted a preclinical study using DMH-induced CRC rat model to evaluate the antitumor potential of our recently synthesized 1,3,4-thiadiazoles. The molecular insights were confirmed through ELISA, qRT-PCR and western blot analyses. The CRC condition was produced in response to COX-2 and IL-6 induced activation of JAK2/STAT3 which, in turn, was due to the enhanced phosphorylation of JAK2 and STAT3. The treatment with 1,3,4-thiadiazole derivatives (VR24 and VR27) caused the significant blockade of this signaling pathway. The behavior of STAT3 populations in response to IL-6 and COX-2 stimulations was further confirmed through data-based mathematical modeling using the quantitative western blot data. Finally, VR24 and VR27 restored the perturbed metabolites associated to DMH-induced CRC as evidenced through ¹H NMR based serum metabolomics. The tumor protecting ability of VR24 and VR27 was found comparable or to some degree better than the marketed chemotherapeutics, 5-flurouracil.

Pramlintide, an antidiabetic, is antineoplastic in colorectal cancer and synergizes with conventional chemotherapy

Background

Approximately 90% of patients with metastatic colorectal cancer fail therapy mainly due to resistance. Taking advantage of currently approved agents for treatment of disease conditions other than cancer for the identification of new adjuvant anticancer therapies is highly encouraged. Pramlintide is a parenteral antidiabetic agent that is currently approved for treatment of types 1 and 2 diabetes mellitus.

Objectives

To address the antineoplastic potential of pramlintide in colorectal cancer and to evaluate the ability of pramlintide to enhance the cytotoxicity of 5-fluorouracil, oxaliplatin, and irinotecan against colorectal cancer cell lines expressing wild-type and mutant p53.

Materials and methods

The antiproliferative effect of pramlintide alone or in combination with 5-fluorouracil, oxaliplatin, or irinotecan in HCT-116 and HT-29 colorectal cancer cell lines was investigated using MTT cell proliferation assay. IC50 values were calculated using Compusyn software 1.0. Synergy values (R) were calculated using the ratio of IC50 of each primary drug alone divided by combination IC50s. For each two pairs of experiments, Student’s t-test was used for analysis. For combination studies, one-way analysis of variance and Tukey post hoc testing was performed using R 3.3.2 software. A p-value of <0.05 was considered significant.

Results

Pramlintide inhibited the growth of HCT-116 and HT-29 in a dose-dependent manner, with higher efficacy against the latter (IC50s; 48.67 and 9.10 μg/mL, respectively; p-value =0.013). Moreover, the addition of 5, 10, and 20 μg/mL of pramlintide to HCT-116 and HT-29 with 5-fluorouracil, oxaliplatin, or irinotecan induced the antiproliferative effect synergistically (R>1.6, p-value <0.05).

Conclusion

Pramlintide enhances the cytotoxicity of conventional chemotherapy against colorectal cancer cell lines harboring wild-type or mutant p53. Thus, pramlintide is a promising potential adjuvant chemotherapy in colorectal cancer.

Panitumumab-Conjugated and Platinum-Cored pH-Sensitive Apoferritin Nanocages for Colorectal Cancer-Targeted Therapy

Apoferritin (AF) is a natural nontoxic iron carrier and has a natural hollow structure that can be used to deliver small molecules. The surface of AF has many amine functional groups that can be modified to create targeted ligands. We loaded oxaliplatin onto AF, which was then used as a template to conjugate with panitumumab via a polyethylene glycol linker. The oxaliplatin-loaded AF conjugated with panitumumab (AFPO) was designed to specifically target cell lines expressing epidermal growth factor receptor (EGFR). AFPO efficiently released oxaliplatin and suppressed tumor cell growth. Furthermore, the novel AFPO nanocages showed significant inhibition and greater accumulation in tumor models with high EGFR expression in vivo. Our study revealed that combining panitumumab and oxaliplatin into one formulation (AFPO nanocage) could be a promising shortcut in clinical applications.

Antitumor activity of HPA3P through RIPK3-dependent regulated necrotic cell death in colon cancer

The antimicrobial peptide HPA3 shows anticancer activity in gastric cancer and leukaemia. However, how HPA3 exerts its anticancer activity, as well as whether it also exhibits activity in other cancers, remains unknown. Therefore, the aim of this study was to evaluate the anticancer activity of HPA3 and its analogues in colon cancer and to elucidate the mechanisms responsible for this activity. HPA3P decreased cell viability, whereas HPA3 and HPA3P2 did not decrease cell viability in colon cancer cells compared with control cells. This reduction in cell viability occurred through necrosis, a conclusion supported by our observation of the release of cellular contents, our intracellular PI staining results, and our observation of the release of HMGB1. Moreover, RIPK3 inhibition blocks the reduction of cell viability by HPA3P. Consistent with this finding, we found that knocking down RIPK3 and MLKL, key necroptosis proteins, attenuates the reductions in cell viability induced by HPA3P. Furthermore, HPA3P can improve the anticancer activity of chemotherapeutic agents and exhibits anticancer activity in other cancer cells. These results suggest that HPA3P may have potential as an anticancer agent in the treatment of colon cancer.

Mitochondrial protein 18 (MTP18) plays a pro-apoptotic role in chemotherapy-induced gastric cancer cell apoptosis

One of the severe limitations of chemotherapy is the development of drug resistance. However, the mechanisms underlying chemotherapy resistance remain to be elucidated. Mitochondrial mediated apoptosis is a form of cell death induced by chemotherapy. Several chemotherapeutic agents have been shown to induce mitochondrial fission, and finally activate the apoptosis cascade in various cancer cells. Here, we report that the mitochondrial membrane protein 18 (MTP18) induced mitochondrial fragmentation in gastric cancer cells under doxorubicin (DOX) exposure. Upon over-expression of MTP18, a sub-cytotoxic dose of DOX could sensitize a significant number of cells to undergo mitochondrial fission and subsequent apoptosis. These findings suggest that MTP18 can enhance the sensitivity of gastric cancer cells to DOX. Mechanistically, we found that MTP18 enriched dynamic-related protein 1 (DRP1) accumulation in mitochondria and it was responsible for mediating DOX-induced signaling required for mitochondrial fission. Intriguingly, MTP18 expression was downregulated during DOX treatment. Thus, down-regulation of MTP18 expression could be one of the resistance factors interfering with DOX-induced apoptosis in gastric cancer cells.

Histone H3K27 Trimethylation Modulates 5-Fluorouracil Resistance by Inhibiting PU.1 Binding to the DPYD Promoter

The antimetabolite 5-fluorouracil (5-FU) is one of the most widely used chemotherapy drugs. Dihydropyrimidine dehydrogenase (DPD) is a major determinant of 5-FU response and toxicity. Although DPYD variants may affect 5-FU metabolism, they do not completely explain the reported variability in DPD function or the resultant differences in treatment response. Here, we report that H3K27 trimethylation (H3K27me3) at the DPYD promoter regulated by Ezh2 and UTX suppresses DPYD expression by inhibiting transcription factor PU.1 binding, leading to increased resistance to 5-FU. Enrichment of H3K27me3 at the DPYD promoter was negatively correlated with both DPYD expression and DPD enzyme activity in peripheral blood specimens from healthy volunteers. Lastly, tumor expression data suggest that DPYD repression by Ezh2 predicts poor survival in 5-FU-treated cancers. Collectively, the findings of the present article suggest that a previously uncharacterized mechanism regulates DPD expression and may contribute to tumor resistance to 5-FU. Cancer Res; 76(21); 6362-73. ©2016 AACR.

Multi-omics landscapes of colorectal cancer subtypes discriminated by an individualized prognostic signature for 5-fluorouracil-based chemotherapy

Until recently, few prognostic signatures for colorectal cancer (CRC) patients receiving 5-fluorouracil (5-FU)-based chemotherapy could be used in clinical practice. Here, using transcriptional profiles for a panel of cancer cell lines and three cohorts of CRC patients, we developed a prognostic signature based on within-sample relative expression orderings (REOs) of six gene pairs for stage II-III CRC patients receiving 5-FU-based chemotherapy. This REO-based signature had the unique advantage of being insensitive to experimental batch effects and free of the impractical data normalization requirement. After stratifying 184 CRC samples with multi-omics data from The Cancer Genome Atlas into two prognostic groups using the REO-based signature, we further revealed that patients with high recurrence risk were characterized by frequent gene copy number aberrations reducing 5-FU efficacy and DNA methylation aberrations inducing distinct transcriptional alternations to confer 5-FU resistance. In contrast, patients with low recurrence risk exhibited deficient mismatch repair and carried frequent gene mutations suppressing cell adhesion. These results reveal the multi-omics landscapes determining prognoses of stage II-III CRC patients receiving 5-FU-based chemotherapy.

Production of truncated MBD4 protein by frameshift mutation in DNA mismatch repair-deficient cells enhances 5-fluorouracil sensitivity that is independent of hMLH1 status

Methyl-CpG binding domain protein 4 (MBD4) is a DNA glycosylase that can remove 5-fluorodeoxyuracil from DNA as well as repair T:G or U:G mismatches. MBD4 is a target for frameshift mutation with DNA mismatch repair (MMR) deficiency, creating a truncated MBD4 protein (TruMBD4) that lacks its glycosylase domain. Here we show that TruMBD4 plays an important role for enhancing 5-fluorouracil (5FU) sensitivity in MMR-deficient colorectal cancer cells. We found biochemically that TruMBD4 binds to 5FU incorporated into DNA with higher affinity than MBD4. TruMBD4 reduced the 5FU affinity of the MMR recognition complexes that determined 5FU sensitivity by previous reports, suggesting other mechanisms might be operative to trigger cytotoxicity. To analyze overall 5FU sensitivity with TruMBD4, we established TruMBD4 overexpression in hMLH1-proficient or -deficient colorectal cancer cells followed by treatment with 5FU. 5FU-treated TruMBD4 cells demonstrated diminished growth characteristics compared to controls, independently of hMLH1 status. Flow cytometry revealed more 5FU-treated TruMBD4 cells in S phase than controls. We conclude that patients with MMR-deficient cancers, which show characteristic resistance to 5FU therapy, may be increased for 5FU sensitivity via secondary frameshift mutation of the base excision repair gene MBD4.

Genetics and Genetic Biomarkers in Sporadic Colorectal Cancer

Sporadic colorectal cancer (CRC) is a somatic genetic disease in which pathogenesis is influenced by the local colonic environment and the patient's genetic background. Consolidating the knowledge of genetic and epigenetic events that occur with initiation, progression, and metastasis of sporadic CRC has identified some biomarkers that might be utilized to predict behavior and prognosis beyond staging, and inform treatment approaches. Modern next-generation sequencing of sporadic CRCs has confirmed prior identified genetic alterations and has classified new alterations. Each patient's CRC is genetically unique, propelled by 2-8 driver gene alterations that have accumulated within the CRC since initiation. Commonly observed alterations across sporadic CRCs have allowed classification into a (1) hypermutated group that includes defective DNA mismatch repair with microsatellite instability and POLE mutations in ∼15%, containing multiple frameshifted genes and BRAF(V600E); (2) nonhypermutated group with multiple somatic copy number alterations and aneuploidy in ∼85%, containing oncogenic activation of KRAS and PIK3CA and mutation and loss of heterozygosity of tumor suppressor genes, such as APC and TP53; (3) CpG island methylator phenotype CRCs in ∼20% that overlap greatly with microsatellite instability CRCs and some nonhypermutated CRCs; and (4) elevated microsatellite alterations at selected tetranucleotide repeats in ∼60% that associates with metastatic behavior in both hypermutated and nonhypermutated groups. Components from these classifications are now used as diagnostic, prognostic, and treatment biomarkers. Additional common biomarkers may come from genome-wide association studies and microRNAs among other sources, as well as from the unique alteration profile of an individual CRC to apply a precision medicine approach to care.