Colon Tumor Research Articles

Male meiotic spindle poles are stabilized by TACC3 and cKAP5/chTOG differently from female meiotic or somatic mitotic spindles in mice.

Transforming acidic acid coiled-coil protein 3 (TACC3) and cytoskeleton associated protein 5 (cKAP5; or colonic hepatic tumor overexpressed gene, chTOG) are vital for spindle assembly and stabilization initiated through TACC3 Aurora-A kinase interaction. Here, TACC3 and cKAP5/chTOG localization with monospecific antibodies is investigated in eGFP-centrin-2- expressing mouse meiotic spermatocytes. Both proteins bind spermatocyte spindle poles but neither kinetochore nor interpolar microtubules, unlike in mitotic mouse fibroblasts or female meiotic oocyte spindles. Spermatocytes do not display a liquid-like spindle domain (LISD), although fusing them into maturing oocytes generates LISD-like TACC3 condensates around sperm chromatin but sparse microtubule assembly. Microtubule inhibitors do not reduce TACC3 and cKAP5/chTOG spindle pole binding. MLN 8237 Aurora-A kinase inhibitor removes TACC3, not cKAP5/chTOG, disrupting spindle organization, chromosome alignment, and impacting spindle pole γ-tubulin intensity. The LISD disruptor 1,6-hexanediol abolished TACC3 in spermatocytes, impacting spindle bipolarity and chromosome organization. Cold microtubule disassembly and rescue experiments in the presence of 1,6-hexanediol reinforce the concept that spermatocyte TACC3 spindle pole presence is not required for spindle pole microtubule assembly. Collectively, meiotic spermatocytes without a LISD localize TACC3 and cKAP5/chTOG exclusively at spindle poles to support meiotic spindle pole stabilization during male meiosis, different from either female meiosis or mitosis.

Efficacy and safety of Shenbai Granules for recurrent colorectal adenoma: A multicenter randomized controlled trial

BackgroundColorectal adenoma is benign glandular tumor of colon, the precursor of colorectal cancer. But no pharmaceutical medication is currently available to treat and prevent adenomas. PurposeTo evaluate efficacy of Shenbai Granules, an herbal medicine formula, in reducing the recurrence of adenomas. Study DesignThis multicenter, randomized, double-blind, placebo-controlled clinical trial was conducted by eight hospitals in China. MethodsPatients who had received complete polypectomy and were diagnosed with adenomas within the recent 6 months were randomly assigned (1:1) to receive either Shenbai granules or placebo twice a day for 6 months. An annual colonoscopy was performed during the 2-year follow-up period. The primary outcome was the proportion of patients with at least one adenoma detected in the modified intention-to-treat (mITT) population during follow-up for 2 years. The secondary outcomes were the proportion of patients with sessile serrated lesions and other specified polypoid lesions. The data were analyzed using logistic regression. ResultsAmong 400 randomized patients, 336 were included in the mITT population. We found significant differences between treatment and placebo groups in the proportion of patients with at least one recurrent adenoma (42.5 % vs. 58.6 %; OR, 0.47; 95 % CI, 0.29–0.74; p = 0.001) and sessile serrated lesion (1.8 % vs. 8.3 %; OR, 0.20; 95 % CI, 0.06–0.72; p = 0.01). There was no significant difference in the proportion of patients developing polypoid lesions (70.7 % vs. 77.5 %; OR, 1.43; 95 % CI, 0.88–2.34; p = 0.15) or high-risk adenomas (9.0 % vs. 13.6 %; OR, 0.63; 95 % CI, 0.32–1.25; p = 0.18). ConclusionShenbai Granules significantly reduced the recurrence of adenomas, indicating that they could be an effective option for adenomas. Future studies should investigate its effects in larger patient populations and explore its mechanism of action to provide more comprehensive evidence for the use of Shenbai Granules in adenoma treatment.

Molecular Targets of the 5-Amido-Carboxamide Bumped Kinase Inhibitor BKI-1748 in Cryptosporidium parvum and HCT-8 Host Cells.

Cryptosporidium parvum is an apicomplexan parasite causing persistent diarrhea in humans and animals. Issuing from target-based drug development, calcium-dependent protein kinase 1 inhibitors, collectively named bumped kinase inhibitors (BKIs), with excellent efficacies in vitro and in vivo have been generated. Some BKIs including BKI-1748 share a core structure with similarities to the first-generation antiprotozoal drug quinine, which is known to exert notorious side effects. Unlike quinine, BKI-1748 rapidly interfered with C. parvum proliferation in the human colon tumor (HCT) cell line HCT-8 cells and caused dramatic effects on the parasite ultrastructure. To identify putative BKI targets in C. parvum and in host cells, we performed differential affinity chromatography with cell-free extracts from non-infected and infected HCT-8 cells using BKI-1748 and quinine epoxy-activated sepharose columns followed by mass spectrometry. C. parvum proteins of interest were identified in eluates from columns coupled to BKI-1748, or in eluates from both BKI-1748 and quinine columns. However, no C. parvum proteins could be identified binding exclusively to BKI-1748. In contrast, 25 BKI-1748-specific binding proteins originating from HCT-8 cells were detected. Moreover, 29 C. parvum and 224 host cell proteins were identified in both BKI-1748 as well as in quinine eluates. In both C. parvum and host cells, the largest subset of binding proteins was involved in RNA binding and modification, with a focus on ribosomal proteins and proteins involved in RNA splicing. These findings extend previous results, showing that BKI-1748 interacts with putative targets involved in common, essential pathways such as translation and RNA processing.

Heart failure-induced microbial dysbiosis contributes to colonic tumour formation in mice.

Heart failure (HF) and cancer are the leading causes of death worldwide. Epidemiological studies revealed that HF patients are prone to develop cancer. Preclinical studies provided some insights into this connection, but the exact mechanisms remain elusive. In colorectal cancer (CRC), gut microbial dysbiosis is linked to cancer progression and recent studies have shown that HF patients display microbial dysbiosis. This current study focussed on the effects of HF-induced microbial dysbiosis on colonic tumour formation. C57BL/6J mice were subjected to myocardial infarction (MI), with sham surgery as control. After six weeks faeces were collected, processed for 16 s rRNA sequencing, and pooled for faecal microbiota transplantation. CRC tumour growth was provoked in germ-free mice by treating them with Azoxymethane/Dextran sodium sulphate. The CRC mice were transplanted with faeces from MI or sham mice. MI-induced HF resulted in microbial dysbiosis, characterized by a decreased α-diversity and microbial alterations on the genus level, several of which have been associated with CRC. We then performed faecal microbiota transplantation with faeces from HF mice in CRC mice, which resulted in a higher endoscopic disease score and an increase in the number of tumours in CRC mice. We demonstrated that MI-induced HF contributes to colonic tumour formation by altering the gut microbiota composition, providing a mechanistic explanation for the observed association between HF and increased risk for cancer. Targeting the microbiome may present as a tool to mitigate HF-associated co-morbidities, especially cancer.

Lovastatin/SN38 co-loaded liposomes amplified ICB therapeutic effect via remodeling the immunologically-cold colon tumor and synergized stimulation of cGAS-STING pathway

Current immune checkpoint blockade (ICB) immunotherapeutics have revolutionized cancer treatment. However, many cancers especially the “immunologically cold” tumors, do not respond to ICB, prompting the search for additional strategies to achieve durable responses. The cGAS-STING pathway, as an essential immune response pathway, has been demonstrated for a potent target to sensitize ICB immunotherapy. However, the low efficiency of conventional STING agonists limits their clinical application. Recent studies have shown that DNA topoisomerase I (TOPI) inhibitor chemodrug SN38 can activate the cGAS-STING pathway and induce an immune response through DNA damage, while the traditional statins medication lovastatin was found to inhibit DNA damage repair, which may in turn upregulate the damaged DNA level. Herein, we have developed a liposomal carrier co-loaded with SN38 and lovastatin (SL@Lip), which can be accumulated in tumors and efficiently released SN38 and lovastatin, addressing the problem of weak solubility of these two drugs. Importantly, lovastatin can increase DNA damage and enhance the activation of cGAS-STING pathway, coordinating with SN38 chemotherapy and exhibiting the enhanced combinational immunotherapy of PD-1 antibody by remodeling the tumor microenvironment in mouse colorectal cancer of both subcutaneous and orthotopic xenograft models. Overall, this study demonstrates that lovastatin-assisted cGAS-STING stimulation mediated by liposomal delivery system significantly strengthened both chemotherapy and immunotherapy of colorectal cancer, providing a clinically translational strategy for combinational ICB therapy in the “immunologically cold” tumors.

Schisandrin B Suppresses Colon Cancer Growth by Inducing Cell Cycle Arrest and Apoptosis: Molecular Mechanism and Therapeutic Potential.

Colon cancer is among the most lethal and prevalent malignant tumors in the world, and the lack of effective therapies highlights the need for novel therapeutic approaches. Schisandrin B (Sch B), a lignan extracted from the fruit ofSchisandra chinensis, has been reported for its anticancer properties. However, to date, no studies have been done to characterize the exact molecular mechanisms underlying the antitumorigenic effects of Sch B in colon cancer. This study aimed to explore the antitumorigenic effects of Sch B in colon cancer and to understand the underlying therapeutic mechanism. A comprehensive analysis of the molecular mechanism underlying the antitumorigenic effects of Sch B on human colon cancer cells was performed using a combination of Raman spectroscopy, RNA-seq, computational docking, and molecular biological experiments. The in vivo efficacy was evaluated by a mouse xenograft model. Sch B reduced cell proliferation and triggered apoptosis in human colon cancer cell lines. Raman spectroscopy, computational, RNA-seq, and molecular and cellular studies revealed that Sch B activated unfolded protein responses by interacting with CHOP and upregulating CHOP, which thereby induced apoptosis. CHOP knockdown alleviated the Sch B-induced reduction in cell viability and apoptosis. Sch B reduced colon tumor growth in vivo. Our findings demonstrated that Sch B induced apoptosis and inhibited cell proliferation and tumor growth in vitro and in vivo. These results provided an essential background for clinical trials examining the effects of Sch B in patients with colon cancer.

SATB1 mediated tumor colonization and β-catenin nuclear localization are associated with colorectal cancer progression

ABSTRACT Colorectal cancer (CRC) is a malignancy with high incidence and poor prognosis. It is urgent to identify valuable biomarkers for early diagnosis and potent therapeutic targets. It has been reported that SATB1 is associated with the malignant progression in CRC. To explore the role of SATB1 in CRC progression and the underlying mechanism, we evaluated the expression of SATB1 in the paired CRC tissues with immunohistochemistry. The results showed that the expression of SATB1 in lymph node metastasis was higher than that in primary lesion, and that in distant organ metastasis was higher than that in primary lesion. The retrospective analysis showed that patients with high expression of SATB1 had a significantly worse prognosis than those with negative and moderate expression. In vitro experiments that employing SATB1 over-expressing and depleted CRC cell lines confirmed that SATB1 contributes to cell proliferation and colonization, while inhibiting cell motility. Furthermore, the tissue immunofluorescence assay, Co-IP and Western blot were conducted to reveal that SATB1 induced translocation of β-catenin and formed a protein complex with it in the nuclei. In conclusion, SATB1 mediated tumor colonization and β-catenin nuclear localization are associated with the malignant progression and poor prognosis of CRC.

MicroRNA-34, microRNA-130, microRNA-148, microRNA-181, microRNA-194 and microRNA-605 expression in colon cancer tissue

Purpose of the study. Determination of the expression of microRNA‑34, microRNA‑130, microRNA‑148, microRNA‑181, microRNA‑194 and microRNA‑605 in colon tumor tissue depending on the clinical and morphological features of the tumor and the effectiveness of treatment.Materials and methods. The study included 56 patients diagnosed with colorectal cancer aged 43 to 75 years with the average age of 54 years. Taking into account the local prevalence of the process patients received surgical or combined treatment, including neoadjuvant chemotherapy, in the clinics of the Cancer Research Institute, Tomsk NRMC. MicroRNA expression was determined by polymerase chain reaction (PCR) in real time.Results. The obtained information revealed the relation of microRNA‑130 to the tumor size. The development of regional metastases was associated with changes in microRNA‑130, microRNA‑194 and microRNA‑605. The level of histological organization of the tumor was associated with microRNA‑34, microRNA‑130, microRNA‑148, and the response to therapy – with microRNA‑130, microRNA‑148 and microRNA‑605. In addition, according to the study, the significance of microRNA‑130 was revealed, which is associated with tumor spread, histological differentiation and response to antitumor therapy.Conclusion. The features of expression of microRNA‑34, microRNA‑130, microRNA‑148, microRNA‑181, microRNA‑194 and microRNA‑605 associated with clinical and morphological features of colon tumors were revealed. Correlations between the studied indicators are noted, which probably determine the outcome and prognosis of the disease.

Anaplastic Lymphoma Kinase (ALK) Inhibitors Show Activity in Colorectal Cancer With ALK Rearrangements: Case Series and Literature Review.

Anaplastic lymphoma kinase (ALK) rearrangement is a well-known driver oncogene detected in approximately 5% of non-small cell lung cancer. However, ALK rearrangement is much less frequent in other solid tumors outside the lungs, such as colorectal cancer (CRC); thus, the optimal management of CRC with ALK rearrangements has yet to be established. In this report, we describe 2 cases of ALK-positive CRC, both of which benefited from ALK tyrosine kinase inhibitor (ALK-TKI) therapy. Case 1 was a postoperative patient with poorly differentiated colon adenocarcinoma, who was diagnosed with metastatic relapse shortly after surgery. Both fluorouracil, leucovorin, and oxaliplatin (FOLFOX) and bevacizumab combined with 5-fluorouracil, l-leucovorin, and irinotecan (FOLFIRI) proved ineffective against the disease. The patient was then treated with ensartinib, as the CAD-ALK fusion gene was detected by genomic analysis. The patient was initially treated with ensartinib monotherapy for 9 months, then with ensartinib combined with local radiotherapy and fruquintinib for another 4 months for isolated hilar hepatic lymph node metastasis. The patient experienced disease progression with an acquired ALK G1202R resistance mutation that responded well to lorlatinib. Case 2 involved a 72-year-old man with advanced colon cancer (pT4bN2aM1b, stage IV) harboring an EML4-ALK fusion. The patient underwent resection of the right colon tumor due to intestinal obstruction, but the disease continued to progress after 12 courses of FOLFIRI and bevacizumab chemotherapy. However, the patient responded remarkably well to alectinib. Our report emphasizes the importance of gene detection in the treatment of malignant tumors, and the significance of ALK mutations in CRC.

Oleic acid-PPARγ-FABP4 loop fuels cholangiocarcinoma colonization in lymph node metastases microenvironment.

Lymph node metastasis is a significant risk factor for patients with cholangiocarcinoma, but the mechanisms underlying cholangiocarcinoma colonization in the lymph node microenvironment remain unclear. We aimed to determine whether metabolic reprogramming fueled the adaptation and remodeling of cholangiocarcinoma cells to the lymph node microenvironment. Here, we applied single-cell RNA sequencing of primary tumor lesions and paired lymph node metastases from patients with cholangiocarcinoma and revealed significantly reduced intertumor heterogeneity and syntropic lipid metabolic reprogramming of cholangiocarcinoma after metastasis to lymph nodes, which was verified by pan-cancer single-cell RNA sequencing analysis, highlighting the essential role of lipid metabolism in tumor colonization in lymph nodes. Metabolomics and in vivo CRISPR/Cas9 screening identified PPARγ as a crucial regulator in fueling cholangiocarcinoma colonization in lymph nodes through the oleic acid-PPARγ-fatty acid-binding protein 4 positive feedback loop by upregulating fatty acid uptake and oxidation. Patient-derived organoids and animal models have demonstrated that blocking this loop impairs cholangiocarcinoma proliferation and colonization in the lymph node microenvironment and is superior to systemic inhibition of fatty acid oxidation. PPARγ-regulated fatty acid metabolic reprogramming in cholangiocarcinoma also contributes to the immune-suppressive niche in lymph node metastases by producing kynurenine and was found to be associated with tumor relapse, immune-suppressive lymph node microenvironment, and poor immune checkpoint blockade response. Our results reveal the role of the oleic acid-PPARγ-fatty acid-binding protein 4 loop in fueling cholangiocarcinoma colonization in lymph nodes and demonstrate that PPARγ-regulated lipid metabolic reprogramming is a promising therapeutic target for relieving cholangiocarcinoma lymph node metastasis burden and reducing further progression.

Anti-OX40 Antibody Combined with HBc VLPs Delays Tumor Growth in a Mouse Colon Cancer Model

ObjectiveCombination immunotherapy strategies targeting OX40, a co-stimulatory molecule that can enhance antitumor immunity by modulating the proliferation, differentiation, and effector function of tumor-infiltrating T cells, have attracted much attention for their excellent therapeutic effects. In this study, we aimed to evaluate the antitumor efficacy of combined anti-OX40 and hepatitis B core virus-like particles (HBc VLPs) therapy using a mouse colon cancer model. MethodsHumanized B-hOX40 mice were injected subcutaneously with MC38 colon tumor cells and treated with HBc VLPs+anti-hOX40 antibody. Tumor growth was monitored. Flow cytometric analysis was performed to evaluate the populations of T cell subsets in the tumors. ResultsThe combination of anti-OX40 with HBc VLPs resulted in a significant delay in tumor growth, suggesting that a potent antitumor immunity was induced by the combination therapy. Further studies revealed that HBc VLPs+anti-OX40 treatment induced a significant increase in effector T cells (Teffs) and a significant decrease in regulatory T cells (Tregs) in the tumor microenvironment (TME), which accounted for the synergistic antitumor effect of anti-OX40 in combination with HBc VLPs. ConclusionCombination therapy of anti-hOX40 and HBc VLPs provides synergistic antitumor activity in colon cancer-bearing mice, which may represent a potential design strategy for cancer immunotherapy.

Banxia Xiexin Decoction delays colitis-to-cancer transition by inhibiting E-cadherin/β-catenin pathway via Fusobacterium nucleatum FadA

Ethnopharmacological relevanceColitis is an important risk factor for the occurrence of colorectal cancer (CRC), and the colonization of Fusobacterium nucleatum (Fn) in the intestines accelerates this transformation process. Banxia Xiexin Decoction (BXD), originating from Shanghanlun, is a classic prescription for treating gastrointestinal diseases. Current researches indicate that BXD can effectively delay the colitis-to-cancer transition, but it is still unclear whether it can inhibit Fn colonization to achieve this delaying effect. Aim of studyThis study explored the effect and mechanism of BXD in inhibiting Fn intestinal colonization to delay colitis-to-cancer transition. Materials and methodsWe constructed a mouse model of colitis-to-cancer transition by regularly gavaging Fn combined with azoxymethane (AOM)/dextran sodium sulfate (DSS), and administered BXD by gavage. We monitored the body weight of mice, measured the length and weight of their colons, and calculated the disease activity index (DAI) score. The growth status of colon tumors was observed by hematoxylin and eosin (H&E) staining, and the changes in gut microbiota in each group of mice were detected by 16S rDNA analysis. Immunohistochemistry was used to detect the expression of E-cadherin and β-catenin in colon tissues, and immunofluorescence was used to observe the infiltration of M2 macrophages in colon tissues. In cell experiments, we established a co-culture model of Fn and colon cancer cells and intervened with BXD-containing serum. Malignant behaviors such as cell proliferation, invasion, and migration were detected, as well as changes in their cell cycle. We examined the protein levels of E-cadherin, β-catenin, Axin2, and Cyclin D1 in each group were detected by Western blot. We used US1 strain (fadA-) as a control and observed the effects of BXD-containing serum on Fn attachment and invasion of colon cancer cells through attachment and invasion experiments. ResultsBXD can inhibit the colitis-to-cancer transition in mice infected with Fn, reduce crypt structure damage, improve gut microbiota dysbiosis, upregulate E-cadherin and decrease β-catenin expression, and reduce infiltration of M2 macrophages, thus inhibiting the process of colitis-to-cancer transition. Cell experiments revealed that BXD-containing serum can inhibit the proliferation, migration, and invasion of colon cancer cells infected with Fn and regulate their cell cycle. More importantly, we found that BXD-containing serum can inhibit the binding of Fn's FadA adhesin to E-cadherin, reduce Fn's attachment and invasion of colon cancer cells, thereby downregulating the E-cadherin/β-catenin signaling pathway. ConclusionsThese findings show that BXD can inhibit Fn colonization by interfering with the binding of FadA to E-cadherin, reducing the activation of the E-cadherin/β-catenin signaling pathway, and ultimately delaying colitis-to-cancer transition.

Glycan-Lectin interactions between platelets and tumor cells drive hematogenous metastasis.

Glycosylation is a ubiquitous cellular or microenvironment-specific post-translational modification that occurs on the surface of normal cells and tumor cells. Tumor cell-associated glycosylation is involved in hematogenous metastasis. A wide variety of tumors undergo aberrant glycosylation to interact with platelets. As platelets have many opportunities to engage circulating tumor cells, they represent an important avenue into understanding the role glycosylation plays in tumor metastasis. Platelet involvement in tumor metastasis is evidenced by observations that platelets protect tumor cells from damaging shear forces and immune system attack, aid metastasis through the endothelium at specific sites, and facilitate tumor survival and colonization. During platelet-tumor-cell interactions, many opportunities for glycan-ligand binding emerge. This review integrates the latest information about glycans, their ligands, and how they mediate platelet-tumor interactions. We also discuss adaptive changes that tumors undergo upon glycan-lectin binding and the impact glycans have on targeted therapeutic strategies for treating tumors in clinical settings.

A4 DNA HYPOMETHYLATION INHIBITS COLITIS-ASSOCIATED CANCER

Abstract Background Colorectal cancer is the second leading cause of cancer death in Canada. A major risk factor for the development of colorectal cancer is chronic inflammation leading to colitis-associated cancer (CAC). We previously described a CAC mouse model in which tumors arise from DCLK1+ cells following loss of the tumor suppressor adenomatous polyposis coli (APC) and induction of colitis. Interestingly, both colitis and CAC are associated with DNA methylation changes that lead to altered gene expression. Moreover, inhibition of DNA methylation has recently been shown to lead to a viral mimicry response. The effects of DNA methylation on colonic tumorigenesis, however, is not known. Aims Thus, we aim to investigate whether inhibition of DNA methylation leads to a viral mimicry response that inhibits colitis-associated tumorigenesis. Methods We first examined the effects of DNA hypomethylation on CAC, by crossing Dclk1-CreERT2/Apcf/f mice to Dnmt1f/f mice which allowed for knock-out of the DNA methyltransferase enzyme DNMT1 in DCLK1+ cells. Dclk1/Apcf/f/Dnmt1f/f and Dclk1/Apcf/f (control group) mice were administered three doses of tamoxifen followed by 2.5% dextran sodium sulfate (DSS) for five days to induce colitis. Fourteen weeks later, we assessed colonic tumor number and size. In a separate cohort of Dclk1/Apcf/f mice treated with DSS, we compared colonic tumor number in mice treated with six doses of 5-AZA-2’-deoxycytidine (5-AZA) versus vehicle. The effects of 5-AZA and DSS on DNA methylation were assessed using the Infinium Mouse Methylation BeadChip Array on colonic epithelial cells isolated from mice treated with vehicle versus 5-AZA in the presence or absence of colitis. RNA expression of viral transposable elements and type I interferon response related genes were measured as a readout of a viral mimicry response. Lastly, we investigated the mechanism by which DNA hypomethylation affects tumorigenesis by crossing Dclk1/Apcf/f/Dnmt1f/f mice to MAVS knockout mice and examining tumor number following tamoxifen and DSS administration as above. Results Deletion of DNMT1 in DCLK1+ cells or treatment with 5-AZA significantly decreased colonic tumor number and size. Treatment with 5-AZA or DNMT1 loss led to DNA hypomethylation and subsequent upregulation of endogenous retroviral expression. Both 5-AZA treatment and DNMT1 knockout in DCLK1+ cells led to increased expression of type I interferon response genes. Knockout of the type I interferon response related gene, MAVS, reversed the anti-tumor effect observed with DNMT1 loss. Conclusions Our findings demonstrate that DNA hypomethylation by 5-AZA or loss of DNMT1 reduces colitis-associated tumorigenesis through activation of a viral mimicry response. Funding Agencies CAG, CIHRCancer Research Society, Canada Foundation for Innovation, Lawson Health Research Institute

Oxygen-supplying ROS-responsive prodrug for synergistic chemotherapy and photodynamic therapy of colon cancer.

Introduction: The synergistic treatment of chemotherapy and photodynamic therapy (PDT) has remarkable potential in cancer therapy. However, challenges remain, such as unstable chemotherapeutic drug release, suboptimal targeting, and reduced efficacy of PDT under hypoxic conditions commonly found in solid tumors. Methods: To address these issues, we use camptothecin (CPT) and pheophorbide a (Pa) incorporated through the functional thioketal, which serves as the reactive oxygen species (ROS)-responsive trigger, to construct a ROS-responsive prodrug (CPT-TK-Pa). Subsequently, we co-loaded it with a platinum nanozyme (PtNP) in distearylphosphatidylethanolamine-polyethylene glycol (DSPE-PEG) to obtain the ROS-responsive prodrug nanoparticle (CPT-TK-Pa/Pt NP). Results and Discussion: Specifically, the incorporated PtNP within CPT-TK-Pa/Pt NP positively catalyzes the conversion of hydrogen peroxide (H2O2) to oxygen, thereby ameliorating the hypoxic state of the tumor. This enhanced oxygen generation could replenish the oxygen that is consumed by Pa during 660nm exposure, enabling controlled CPT release and amplifying the photodynamic response. In vitro investigations reveal the potency of CPT-TK-Pa/Pt NPs in inhibiting colon tumor cells. Given its ROS-responsive release mechanism and enhanced PDT efficacy, CPT-TK-Pa/Pt NP has the potential to be a promising candidate for cancer therapy.

Sex differences in colonic gene expression and fecal microbiota composition in a mouse model of obesity-associated colorectal cancer

This study investigated the sex-specific correlation between obesity and colorectal cancer emphasizing a more pronounced association in males. Estrogen, chromosomal genes, and gut bacteria were assessed in C57BL6/J male, female and ovariectomized (OVX) female mice, subjected to either a low-fat diet (LFD) or high-fat diet (HFD) for 14 weeks. Induction of colon tumor involved azoxymethane (10 mg/kg) administration, followed by three cycles of dextran sulfate sodium. Male mice on HFD exhibited higher final body weight and increased colon tumors compared to females. Colonic mucin 2 expression was significantly higher in females. HFD-modulated differentially expressed genes numbered 290 for males, 64 for females, and 137 for OVX females. Only one up-regulated gene (Gfra3) overlapped between females and OVX females, while two down-regulated genes (Thrsp and Gbp11) overlapped between males and OVX females. Genes up-regulated by HFD in males were linked to cytokine-cytokine interaction, HIF-1 signaling pathway, central carbon metabolism in cancer. Sex-specific changes in gut microbial composition in response to HFD were observed. These findings suggest a male-specific vulnerability to HFD-induced colon tumor formation, implicating key genes and colonic bacteria in colon tumorigenesis.

The dopamine transporter antagonist vanoxerine inhibits G9a and suppresses cancer stem cell functions in colon tumors.

Cancer stem cells (CSCs), functionally characterized by self-renewal and tumor-initiating activity, contribute to decreased tumor immunogenicity, while fostering tumor growth and metastasis. Targeting G9a histone methyltransferase (HMTase) effectively blocks CSC functions in colorectal tumors by altering pluripotent-like molecular networks; however, existing molecules directly targeting G9a HMTase activity failed to reach clinical stages due to safety concerns. Using a stem cell-based phenotypic drug-screening pipeline, we identified the dopamine transporter (DAT) antagonist vanoxerine, a compound with previously demonstrated clinical safety, as a cancer-specific downregulator of G9a expression. Here we show that gene silencing and chemical antagonism of DAT impede colorectal CSC functions by repressing G9a expression. Antagonizing DAT also enhanced tumor lymphocytic infiltration by activating endogenous transposable elements and type-I interferon response. Our study unveils the direct implication of the DAT-G9a axis in the maintenance of CSC populations and an approach to improve antitumor immune response in colon tumors.

Manipulating Redox Homeostasis of Cancer Stem Cells Overcome Chemotherapeutic Resistance through Photoactivatable Biomimetic Nanodiscs.

Tumor heterogeneity remains a significant obstacle in cancer therapy due to diverse cells with varying treatment responses. Cancer stem-like cells (CSCs) contribute significantly to intratumor heterogeneity, characterized by high tumorigenicity and chemoresistance. CSCs reside in the depth of the tumor, possessing low reactive oxygen species (ROS) levels and robust antioxidant defense systems to maintain self-renewal and stemness. A nanotherapeutic strategy is developed using tumor-penetrating peptide iRGD-modified high-density lipoprotein (HDL)-mimetic nanodiscs (IPCND) that ingeniously loaded with pyropheophorbide-a (Ppa), bis (2-hydroxyethyl) disulfide (S-S), and camptothecin (CPT) by synthesizing two amphiphilic drug-conjugated sphingomyelin derivatives. Photoactivatable Ppa can generate massive ROS which as intracellular signaling molecules effectively shut down self-renewal and trigger differentiation of the CSCs, while S-S is utilized to deplete GSH and sustainably imbalance redox homeostasis by reducing ROS clearance. Simultaneously, the depletion of GSH is accompanied by the release of CPT, which leads to subsequent cell death. This dual strategy successfully disturbed the redox equilibrium of CSCs, prompting their differentiation and boosting the ability of CPT to kill CSCs upon laser irradiation. Additionally, it demonstrated a synergistic anti-cancer effect by concurrently eliminating therapeutically resistant CSCs and bulk tumor cells, effectively suppressing tumor growth in CSC-enriched heterogeneous colon tumor mouse models.

Delivery of Interferon β-Encoding Plasmid via Lipid Nanoparticle Restores Interferon β Expression to Enhance Antitumor Immunity in Colon Cancer.

Type I interferon (IFN-I) plays a critical role in host cancer immunosurveillance, but its expression is often impaired in the tumor microenvironment. We aimed at testing the hypothesis that cationic lipid nanoparticle delivery of interferon β (IFNβ)-encoding plasmid to tumors is effective in restoring IFNβ expression to suppress tumor immune evasion. We determined that IFN-I function in tumor suppression depends on the host immune cells. IFN-I activates the expression of Cxcl9 and Cxcl10 to enhance T cell tumor infiltration. RNA-Seq detected a low level of IFNα13 and IFNβ in colon tumor tissue. scRNA-Seq revealed that IFNβ is expressed in immune cell subsets in non-neoplastic human tissues and to a lesser degree in human colon tumor tissues. Forced expression of IFNα13 and IFNβ in colon tumor cells up-regulates major histocompatibility complex I (MHC I) expression and suppresses colon tumor growth in vivo. In human cancer patients, IFNβ expression is positively correlated with human leukocyte antigen (HLA) expression, and IFN-I signaling activation correlates with the patient response to PD-1 blockade immunotherapy. To translate this finding to colon cancer immunotherapy, we formulated a 1,2-dioleoyl-3-trimethylammonium propane (DOTAP)-cholesterol-encapsulated IFNβ-encoding plasmid (IFNBCOL01). IFNBCOL01 transfects colon tumor cells to express IFNβ to increase the level of MHC I expression. IFNBCOL01 therapy transfects tumor cells and tumor-infiltrating immune cells to produce IFNβ to activate MHC I and granzyme B expression and inhibits colon tumor growth in mice. Our data determine that lipid nanoparticle delivery of IFNβ-encoding plasmid DNA enhances tumor immunogenicity and T cell effector function to suppress colon tumor growth in vivo.

Location matters: spatial dynamics of tumor-infiltrating T cell subsets is prognostic in colon cancer.

Colon cancer is a heterogeneous disease and consists of various molecular subtypes. Despite advances in high-throughput expression profiling, limitations remain in predicting clinical outcome and assigning specific treatment to individual cases. Tumor-immune interactions play a critical role, with tumors that activate the immune system having better outcome for the patient. The localization of T cells within tumor epithelium, to enable direct contact, is essential for antitumor function, but bulk DNA/RNA sequencing data lacks spatial distribution information. In this study, we provide spatial T cell tumor distribution and connect these data with previously determined genomic data in the AC-ICAM colon cancer patient cohort. Colon cancer patients (n=90) with transcriptome data available were selected. We used a custom multiplex immunofluorescence assay on colon tumor tissue sections for quantifying T cell subsets spatial distribution in the tumor microenvironment, in terms of cell number, location, mutual distance, and distance to tumor cells. Statistical analyses included the previously determined Immunologic Constant of Rejection (ICR) transcriptome correlation and patient survival, revealing potential prognostic value in T cell spatial distribution. T cell phenotypes were characterized and CD3+CD8-FoxP3- T cells were found to be the predominant tumor-infiltrating subtype while CD3+FoxP3+ T cells and CD3+CD8+ T cells showed similar densities. Spatial distribution analysis elucidated that proliferative T cells, characterized by Ki67 expression, and Granzyme B-expressing T cells were predominantly located within the tumor epithelium. We demonstrated an increase in immune cell density and a decrease in the distance of CD3+CD8+ T cells to the nearest tumor cell, in the immune active, ICR High, immune subtypes. Higher densities of stromal CD3+FoxP3+ T cells showed enhanced survival outcomes, and patients exhibited superior clinical benefits when greater spatial distances were observed between CD3+CD8-FoxP3- or CD3+CD8+ T cells and CD3+FoxP3+ T cells. Our study's in-depth analysis of the spatial distribution and densities of major T cell subtypes within the tumor microenvironment has provided valuable information that paves the way for further research into the intricate relationships between immune cells and colon cancer development.