Colorectal cancer is a major cause of cancer-related deaths worldwide. Immune checkpoint blockade therapies are effective in 30%–60% of the microsatellite instable–high subtype. Unfortunately, most ...patients with colorectal cancer (>85%) have microsatellite stable tumors that do not respond. In this study, we aimed to decipher the underlying tumor-intrinsic mechanisms critical for improving immunotherapy in colorectal cancer.
We used human and mouse tumor samples, cell lines, human colorectal cancer organoids, and various syngeneic orthotopic mouse models of late-stage colorectal cancer to define the effects of tumor cell–secreted extracellular vesicles (EVs) on antitumor immune response.
Our analyses of human colorectal cancer immune profiles and tumor–immune cell interactions showed that tumor-secreted EVs containing microRNA miR-424 suppressed the CD28-CD80/86 costimulatory pathway in tumor-infiltrating T cells and dendritic cells, leading to immune checkpoint blockade resistance. Modified tumor-secreted EVs with miR-424 knocked down enhanced T-cell–mediated antitumor immune response in colorectal cancer tumor models and increased the immune checkpoint blockade response. Intravenous injections of modified tumor-secreted EVs induced tumor antigen–specific immune responses and boosted the immune checkpoint blockade efficacy in colorectal cancer models that mimic aggressively progressing, late-stage disease.
Collectively, we show a critical role for tumor-secreted EVs in antitumor immune regulation and immunotherapy response, which could be developed as a novel treatment for immune checkpoint blockade–resistant colorectal cancer.
Display omitted
Osteosarcoma (OS) is a heterogeneous and rare disease with a disproportionate impact because it mainly affects children and adolescents. Lamentably, more than half of patients with OS succumb to ...metastatic disease. Clarification of the etiology of the disease, development of better strategies to manage progression, and methods to guide personalized treatments are among the unmet health needs for OS patients. Progress in managing the disease has been hindered by the extreme heterogeneity of OS; thus, better models that accurately recapitulate the natural heterogeneity of the disease are needed. For this study, we used cell lines derived from two spontaneous canine OS tumors with distinctly different biological behavior (OS-1 and OS-2) for heterotypic in vivo modeling that recapitulates the heterogeneous biology and behavior of this disease. Both cell lines demonstrated stability of the transcriptome when grown as orthotopic xenografts in athymic nude mice. Consistent with the behavior of the original tumors, OS-2 xenografts grew more rapidly at the primary site and had greater propensity to disseminate to lung and establish microscopic metastasis. Moreover, OS-2 promoted formation of a different tumor-associated stromal environment than OS-1 xenografts. OS-2-derived tumors comprised a larger percentage of the xenograft tumors than OS-1-derived tumors. In addition, a robust pro-inflammatory population dominated the stromal cell infiltrates in OS-2 xenografts, whereas a mesenchymal population with a gene signature reflecting myogenic signaling dominated those in the OS-1 xenografts. Our studies show that canine OS cell lines maintain intrinsic features of the tumors from which they were derived and recapitulate the heterogeneous biology and behavior of bone cancer in mouse models. This system provides a resource to understand essential interactions between tumor cells and the stromal environment that drive the progression and metastatic propensity of OS.
Osteosarcoma is an aggressive primary bone tumor in humans and is among the most common cancer afflicting dogs. Despite surgical advancements and intensification of chemo- and targeted therapies, the ...survival outcome for osteosarcoma patients is, as of yet, suboptimal. The presence of metastatic disease at diagnosis or its recurrence after initial therapy is a major factor for the poor outcomes. It is thought that most human and canine patients have at least microscopic metastatic lesions at diagnosis. Osteosarcoma in dogs occurs naturally with greater frequency and shares many biological and clinical similarities with osteosarcoma in humans. From a genetic perspective, osteosarcoma in both humans and dogs is characterized by complex karyotypes with highly variable structural and numerical chromosomal aberrations. Similar molecular abnormalities have been observed in human and canine osteosarcoma. For instance, loss of
and
regulated pathways are common. While there are several oncogenes that are commonly amplified in both humans and dogs, such as
and
, no commonly activated proto-oncogene has been identified that could form the basis for targeted therapies. It remains possible that recurrent aberrant gene expression changes due to gene amplification or epigenetic alterations could be uncovered and these could be used for developing new, targeted therapies. However, the remarkably high genomic complexity of osteosarcoma has precluded their definitive identification. Several advantageous murine models of osteosarcoma have been generated. These include spontaneous and genetically engineered mouse models, including a model based on forward genetics and transposon mutagenesis allowing new genes and genetic pathways to be implicated in osteosarcoma development. The proposition of this review is that careful comparative genomic studies between human, canine and mouse models of osteosarcoma may help identify commonly affected and targetable pathways for alternative therapies for osteosarcoma patients. Translational research may be found through a path that begins in mouse models, and then moves through canine patients, and then human patients.
Many soft tissue tumors recapitulate features of normal connective tissue. We hypothesize that different types of fibroblastic tumors are representative of different populations of fibroblastic cells ...or different activation states of these cells. We examined two tumors with fibroblastic features, solitary fibrous tumor (SFT) and desmoid-type fibromatosis (DTF), by DNA microarray analysis and found that they have very different expression profiles, including significant differences in their patterns of expression of extracellular matrix genes and growth factors. Using immunohistochemistry and in situ hybridization on a tissue microarray, we found that genes specific for these two tumors have mutually specific expression in the stroma of nonneoplastic tissues. We defined a set of 786 gene spots whose pattern of expression distinguishes SFT from DTF. In an analysis of DNA microarray gene expression data from 295 previously published breast carcinomas, we found that expression of this gene set defined two groups of breast carcinomas with significant differences in overall survival. One of the groups had a favorable outcome and was defined by the expression of DTF genes. The other group of tumors had a poor prognosis and showed variable expression of genes enriched for SFT type. Our findings suggest that the host stromal response varies significantly among carcinomas and that gene expression patterns characteristic of soft tissue tumors can be used to discover new markers for normal connective tissue cells.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Expression level of many genes shows abundant natural variation in human populations. The variations in gene expression are believed to contribute to phenotypic differences. Emerging evidence has ...shown that microRNAs (miRNAs) are one of the key regulators of gene expression. However, past studies have focused on the miRNA target genes and used loss- or gain-of-function approach that may not reflect natural association between miRNA and mRNAs.
To examine miRNA regulatory effect on global gene expression under endogenous condition, we performed pair-wise correlation coefficient analysis on expression levels of 366 miRNAs and 14,174 messenger RNAs (mRNAs) in 90 immortalized lymphoblastoid cell lines, and observed significant correlations between the two species of RNA transcripts. We identified a total of 7,207 significantly correlated miRNA-mRNA pairs (false discovery rate q<0.01). Of those, 4,085 pairs showed positive correlations while 3,122 pairs showed negative correlations. Gene ontology analyses on the miRNA-correlated genes revealed significant enrichments in several biological processes related to cell cycle, cell communication and signal transduction. Individually, each of three miRNAs (miR-331, -98 and -33b) demonstrated significant correlation with the genes in cell cycle-related biological processes, which is consistent with important role of miRNAs in cell cycle regulation.
This study demonstrates feasibility of using naturally expressed transcript profiles to identify endogenous correlation between miRNA and miRNA. By applying this genome-wide approach, we have identified thousands of miRNA-correlated genes and revealed potential role of miRNAs in several important cellular functions. The study results along with accompanying data sets will provide a wealth of high-throughput data to further evaluate the miRNA-regulated genes and eventually in phenotypic variations of human populations.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Complex interactions between mRNAs and microRNAs influence cellular functions. The mRNA-microRNA interactions also determine the post-transcriptional availability of mRNAs and unbound microRNAs. ...MicroRNAs binds to one or more microRNA response elements (MREs) located on the 3′UTR of mRNAs. In this study, we leveraged MREs and their frequencies in cancer and matched normal tissues to obtain insights into disease-specific interactions between mRNAs and microRNAs. We developed a bioinformatics method “ReMIx” that utilizes RNA sequencing (RNA-Seq) data to quantify MRE frequencies across the transcriptome. We applied ReMIx to triple-negative (TN) breast cancer tumor-normal adjacent pairs and identified MREs specific to TN tumors. ReMIx identified candidate mRNAs and microRNAs in the MAPK signaling cascade. Further analysis of MAPK gene regulatory networks revealed microRNA partners that influence and modulate MAPK signaling. In conclusion, we demonstrate a novel method of using MREs in the identification of functionally relevant mRNA-microRNA interactions in TN breast cancer.
Display omitted
•Bioinformatics method ReMIx identify differential microRNA response rlements (MRE)•Tumor-specific MREs frequency observed in triple-negative breast cancer (TNBC)•MRE analysis identify MAPK signaling genes as therapeutic target for TNBC•MREs frequency can be used to identify pathologically relevant pathways
Biological Sciences; Bioinformatics; Cancer Systems Biology; Cancer
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Leiomyosarcomas (LMSs) constitute approximately one quarter of all sarcomas and are usually defined by morphologic criteria and/or immunoreactivity for actin or desmin. Among high-grade lesions, the ...distinction from undifferentiated pleomorphic sarcoma (UPS) can be problematic, and previous studies have shown that a significant number of LMS cases may be hiding under the diagnosis of UPS. We recently described 3 novel molecular LMS subtypes that are distributed similarly over LMSs of gyneocologic and non-gyneocologic origins. The group 1 subtype shows an improved disease-specific survival compared with the other 2 groups that is independent of histologic grade. Group 1 comprises approximately 25% of all LMSs, and is defined by a shared pattern of gene expression, a distinct pattern of genomic changes, and reactivity for at least 3 of 5 immunohistochemistry (IHC) markers (smooth muscle gamma actin, calsequestrin 2, human muscle cofilin2, myosin light chain kinase, and sarcolemmal membrane associated protein), as tested on 271 cases of LMS in tissue microarrays. These IHC markers have not been well characterized in non-LMS sarcomas. Here we provide a characterization of these 5 markers across normal tissues, an additional 59 cases of LMS, and a wide range of 565 non-LMS soft tissue tumors from 44 diagnostic categories, with a focus on UPS. When analyzed individually, the 5 markers were found to be expressed in many sarcomas other than LMSs. However, when analyzed by the same criteria used for the recognition of group 1 LMSs, in which a case is scored positive when at least 3 of 5 markers reacted, coordinate expression was seen in significant numbers of cases from only 3 diagnostic groups that included 22% of leiomyomas (n=22), 16% of gastrointestinal stromal tumors (n=43), and 18% of endometrial stromal sarcomas (n=11). In addition, 5% (n=57) of UPSs showed a staining pattern similar to that seen in group 1 LMSs. To further examine the possibility that group 1 LMS constitutes a small part of cases diagnosed as UPS, we examined the expression of the top 500 genes from the group 1 LMS expression signature in 29 UPSs by complementary DNA microarray. Unsupervised hierarchical clustering of 29 UPS expression showed that 2 (7%) had coordinated high levels of expression of genes from the group 1 LMS signature, a rate similar to that seen by IHC analysis. These findings show that group 1 LMS IHC markers smooth muscle gamma actin, calsequestrin 2, human muscle cofilin2, myosin light chain kinase, and sarcolemmal membrane associated protein when coordinately expressed have specificity for a subset of LMS when compared with other sarcomas, and may be useful for the recognition of group 1 LMS cases within cases diagnosed as UPS.
Despite significant advances in the screening, diagnosis, and treatment of colorectal cancer (CRC) immune checkpoint inhibitors (ICIs) continue to have limited utility outside of microsatellite-high ...disease. Given the durable response to immunotherapy seen across malignancies, increasing CRC response rates to ICI therapy is an active area of clinical research. An increasing body of work has demonstrated that tumor-derived extracellular vesicles (TEVs) are key modulators in tumor signaling and the determinants of the tumor microenvironment. Pre-clinical models have shown that TEVs are directly involved in antigen presentation and are involved in radiation-induced DNA damage signaling. Both direct and indirect modifications of these TEVs can alter CRC immunogenicity and ICI treatment response, making them attractive targets for potential therapeutic development. In addition, modified TEVs can be developed using several different mechanisms, with varied cargo including micro-RNAs and small peptide molecules. Recent work has shown strong pre-clinical evidence of injected modified TEV-induced ICI activity, with knockdown of the micro-RNA miR-424 in TEVs improving CRC immunogenicity and increasing anti-PD-1 activity in mouse models. Clinical trials are ongoing in the evaluation of modified TEVs in cancer therapy, but they appear to be a promising therapeutic target in CRC.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
70.
MicroRNAs as Biomarkers in Cancer Sundarbose, Kamini; Kartha, Reena V; Subramanian, Subbaya
Diagnostics,
01/2013, Volume:
3, Issue:
1
Journal Article, Book Review
Peer reviewed
Open access
MicroRNAs (miRNAs) are small non-coding RNA molecules, which in recent years have emerged to have enormous potential as biomarkers. Recently, there have been significant developments in understanding ...miRNA biogenesis, their regulatory mechanisms and role in disease process, and their potential as effective therapies. The identification of miRNAs as biomarkers provides possibilities for development of less or non-invasive and more specific methods for monitoring tumor growth and progression. This review summarizes the recent developments in methods to detect and quantitate miRNAs in body fluids and their applications as biomarkers in cancers. The prospect of miRNAs as potential diagnostic and prognostic biomarkers with clinical applications is significant as more evidence points to their central role in cancer pathobiology.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
PDF
