Cancer signature ensemble integrating cfDNA methylation, copy number, and fragmentation facilitates multi-cancer early detection.

Cell-free DNA (cfDNA) sequencing has demonstrated great potential for early cancer detection. However, most large-scale studies have focused only on either targeted methylation sites or whole-genome sequencing, limiting comprehensive analysis that integrates both epigenetic and genetic signatures. In this study, we present a platform that enables simultaneous analysis of whole-genome methylation, copy number, and fragmentomic patterns of cfDNA in a single assay. Using a total of 950 plasma (361 healthy and 589 cancer) and 240 tissue samples, we demonstrate that a multifeature cancer signature ensemble (CSE) classifier integrating all features outperforms single-feature classifiers. At 95.2% specificity, the cancer detection sensitivity with methylation, copy number, and fragmentomic models was 77.2%, 61.4%, and 60.5%, respectively, but sensitivity was significantly increased to 88.9% with the CSE classifier (p value < 0.0001). For tissue of origin, the CSE classifier enhanced the accuracy beyond the methylation classifier, from 74.3% to 76.4%. Overall, this work proves the utility of a signature ensemble integrating epigenetic and genetic information for accurate cancer detection.

Epigenetic insights into colorectal cancer: comprehensive genome-wide DNA methylation profiling of 294 patients in Korea.

DNA methylation regulates gene expression and contributes to tumorigenesis in the early stages of cancer. In colorectal cancer (CRC), CpG island methylator phenotype (CIMP) is recognized as a distinct subset that is associated with specific molecular and clinical features. In this study, we investigated the genomewide DNA methylation patterns among patients with CRC. The methylation data of 1 unmatched normal, 142 adjacent normal, and 294 tumor samples were analyzed. We identified 40,003 differentially methylated positions with 6,933 (79.8%) hypermethylated and 16,145 (51.6%) hypomethylated probes in the genic region. Hypermethylated probes were predominantly found in promoter-like regions, CpG islands, and N shore sites; hypomethylated probes were enriched in open-sea regions. CRC tumors were categorized into three CIMP subgroups, with 90 (30.6%) in the CIMP-high (CIMP-H), 115 (39.1%) in the CIMP-low (CIMP-L), and 89 (30.3%) in the non-CIMP group. The CIMP-H group was associated with microsatellite instabilityhigh tumors, hypermethylation of MLH1, older age, and rightsided tumors. Our results showed that genome-wide methylation analyses classified patients with CRC into three subgroups according to CIMP levels, with clinical and molecular features consistent with previous data. [BMB Reports 2023; 56(10): 563-568].

Spatial and clonality-resolved 3D cancer genome alterations reveal enhancer-hijacking as a potential prognostic marker for colorectal cancer.

The regulatory effect of non-coding large-scale structural variations (SVs) on proto-oncogene activation remains unclear. This study investigated SV-mediated gene dysregulation by profiling 3D cancer genome maps from 40 patients with colorectal cancer (CRC). We developed a machine learning-based method for spatial characterization of the altered 3D cancer genome. This revealed a frequent establishment of "de novo chromatin contacts" that can span multiple topologically associating domains (TADs) in addition to the canonical TAD fusion/shuffle model. Using this information, we precisely identified super-enhancer (SE)-hijacking and its clonal characteristics. Clonal SE-hijacking genes, such as TOP2B, are recurrently associated with cell-cycle/DNA-processing functions, which can potentially be used as CRC prognostic markers. Oncogene activation and increased drug resistance due to SE-hijacking were validated by reconstructing the patient's SV using CRISPR-Cas9. Collectively, the spatial and clonality-resolved analysis of the 3D cancer genome reveals regulatory principles of large-scale SVs in oncogene activation and their clinical implications.

Bone morphogenetic protein-7 attenuates pancreatic damage under diabetic conditions and prevents progression to diabetic nephropathy via inhibition of ferroptosis.

Background: Approximately 30% of diabetic patients develop diabetic nephropathy, a representative microvascular complication. Although the etiological mechanism has not yet been fully elucidated, renal tubular damage by hyperglycemia-induced expression of transforming growth factor-ß (TGF-ß) is known to be involved. Recently, a new type of cell death by iron metabolism called ferroptosis was reported to be involved in kidney damage in animal models of diabetic nephropathy, which could be induced by TGF-ß. Bone morphogenetic protein-7 (BMP7) is a well-known antagonist of TGF-ß inhibiting TGF-ß-induced fibrosis in many organs. Further, BMP7 has been reported to play a role in the regeneration of pancreatic beta cells in diabetic animal models. Methods: We used protein transduction domain (PTD)-fused BMP7 in micelles (mPTD-BMP7) for long-lasting in vivo effects and effective in vitro transduction and secretion. Results: mPTD-BMP7 successfully accelerated the regeneration of diabetic pancreas and impeded progression to diabetic nephropathy. With the administration of mPTD-BMP7, clinical parameters and representative markers of pancreatic damage were alleviated in a mouse model of streptozotocin-induced diabetes. It not only inhibited the downstream genes of TGF-ß but also attenuated ferroptosis in the kidney of the diabetic mouse and TGF-ß-stimulated rat kidney tubular cells. Conclusion: BMP7 impedes the progression of diabetic nephropathy by inhibiting the canonical TGF-ß pathway, attenuating ferroptosis, and helping regenerate diabetic pancreas.

Glycogen Synthase Kinase-3 Interaction Domain Enhances Phosphorylation of SARS-CoV-2 Nucleocapsid Protein.

A structural protein of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2), nucleocapsid (N) protein is phosphorylated by glycogen synthase kinase (GSK)-3 on the serine/arginine (SR) rich motif located in disordered regions. Although phosphorylation by GSK-3ß constitutes a critical event for viral replication, the molecular mechanism underlying N phosphorylation is not well understood. In this study, we found the putative alpha-helix L/FxxxL/AxxRL motif known as the GSK-3 interacting domain (GID), found in many endogenous GSK-3ß binding proteins, such as Axins, FRATs, WWOX, and GSKIP. Indeed, N interacts with GSK-3ß similarly to Axin, and Leu to Glu substitution of the GID abolished the interaction, with loss of N phosphorylation. The N phosphorylation is also required for its structural loading in a virus-like particle (VLP). Compared to other coronaviruses, N of Sarbecovirus lineage including bat RaTG13 harbors a CDK1-primed phosphorylation site and Gly-rich linker for enhanced phosphorylation by GSK-3ß. Furthermore, we found that the S202R mutant found in Delta and R203K/G204R mutant found in the Omicron variant allow increased abundance and hyper-phosphorylation of N. Our observations suggest that GID and mutations for increased phosphorylation in N may have contributed to the evolution of variants.

A micellized bone morphogenetic protein-7 prodrug ameliorates liver fibrosis by suppressing transforming growth factor-ß signaling.

Bone morphogenetic protein-7 (BMP-7) antagonizes transforming growth factor-ß (TGF-ß), which is critically involved in liver fibrogenesis. Here, we designed a micelle formulation consisting of a protein transduction domain (PTD) fused BMP-7 polypeptide (mPTD-BMP-7) to enhance endocytic delivery, and investigated its ability to ameliorate liver fibrosis. The mPTD-BMP-7 formulation was efficiently delivered into cells via endocytosis, where it inhibited TGF-ß mediated epithelial-mesenchymal transition. After successfully demonstrating delivery of fluorescently labeled mPTD-BMP-7 into the murine liver in vivo, we tested the mPTD-BMP-7 formulation in a murine liver fibrosis model, developed by repeated intraperitoneal injection of hepatotoxic carbon tetrachloride, twice weekly from 4 to 16 weeks. mPTD-BMP-7 effects were tested by injecting the mPTD-BMP-7 formulation (or vehicle control) into the lateral tail at a dose of 50 (n=8) or 500 µg/kg (n=10), also twice per week from 4 to 16 weeks. Vehicle-treated control mice developed fibrous septa surrounding the liver parenchyma and marked portal-to-portal bridging with occasional nodules, whereas mice treated with mPTD-BMP-7 showed only fibrous expansion of some portal areas, with or without short fibrous septa. Using the Ishak scoring system, we found that the fibrotic burden was significantly lower in mPTD-BMP-7 treated mice than in control mice (all P<0.001). Treatment with mPTD-BMP-7 protected tight junctions between hepatocytes and reduced extracellular matrix protein levels. It also significantly decreased mRNA levels of collagen 1A, smooth muscle α-actin, and connective tissue growth factor compared with that in control mice (all P<0.001). Collectively, out results indicate that mPTD-BMP-7, a prodrug formulation of BMP-7, ameliorates liver fibrosis by suppressing the TGF-ß signaling pathway in a murine liver fibrosis model.

EMT-mediated regulation of CXCL1/5 for resistance to anti-EGFR therapy in colorectal cancer.

The emergence of RAS/RAF mutant clone is the main feature of EGFR inhibitor resistance in KRAS wild-type colon cancer. However, its molecular mechanism is thought to be multifactorial, mainly due to cellular heterogeneity. In order to better understand the resistance mechanism in a single clone level, we successfully isolated nine cells with cetuximab-resistant (CR) clonality from in vitro system. All CR cells harbored either KRAS or BRAF mutations. Characteristically, these cells showed a higher EMT (Epithelial to mesenchymal transition) signature, showing increased EMT markers such as SNAI2. Moreover, the expression level of CXCL1/5, a secreted protein, was significantly higher in CR cells compared to the parental cells. In these CR cells, CXCL1/5 expression was coordinately regulated by SNAI2/NFKB and transactivated EGFR through CXCR/MMPI/EGF axis via autocrine singling. We also observed that combined cetuximab/MEK inhibitor not only showed growth inhibition but also reduced the secreted amounts of CXCL1/5. We further found that serum CXCL1/5 level was positively correlated with the presence of RAS/RAF mutation in colon cancer patients during cetuximab therapy, suggesting its role as a biomarker. These data indicated that the application of serum CXCL1/5 could be a potential serologic biomarker for predicting resistance to EGFR therapy in colorectal cancer.

Patient-derived organoids as a preclinical platform for precision medicine in colorectal cancer.

Patient-derived organoids are being considered as models that can help guide personalized therapy through in vitro anticancer drug response evaluation. However, attempts to quantify in vitro drug responses in organoids and compare them with responses in matched patients remain inadequate. In this study, we investigated whether drug responses of organoids correlate with clinical responses of matched patients and disease progression of patients. Organoids were established from 54 patients with colorectal cancer who (except for one patient) did not receive any form of therapy before, and tumor organoids were assessed through whole-exome sequencing. For comparisons of in vitro drug responses in matched patients, we developed an 'organoid score' based on the variable anticancer treatment responses observed in organoids. Very interestingly, a higher organoid score was significantly correlated with a lower tumor regression rate after the standard-of-care treatment in matched patients. Additionally, we confirmed that patients with a higher organoid score (≥ 2.5) had poorer progression-free survival compared with those with a lower organoid score (< 2.5). Furthermore, to assess potential drug repurposing using an FDA-approved drug library, ten tumor organoids derived from patients with disease progression were applied to a simulation platform. Taken together, organoids and organoid scores can facilitate the prediction of anticancer therapy efficacy, and they can be used as a simulation model to determine the next therapeutic options through drug screening. Organoids will be an attractive platform to enable the implementation of personalized therapy for colorectal cancer patients.

Direct Detection of Low Abundance Genes of Single Point Mutation.

Cell-free DNA (cfDNA) analysis, specifically circulating tumor DNA (ctDNA) analysis, provides enormous opportunities for noninvasive early assessment of cancers. To date, PCR-based methods have led this field. However, the limited sensitivity/specificity of PCR-based methods necessitates the search for new methods. Here, we describe a direct approach to detect KRAS G12D mutated genes in clinical ctDNA samples with the utmost LOD and sensitivity/specificity. In this study, MutS protein was immobilized on the tip of an atomic force microscope (AFM), and the protein sensed the mismatched sites of the duplex formed between the capture probe on the surface and mutated DNA. A noteworthy LOD (3 copies, 0.006% allele frequency) was achieved, along with superb sensitivity/specificity (100%/100%). These observations demonstrate that force-based AFM, in combination with the protein found in nature and properly designed capture probes/blockers, represents an exciting new avenue for ctDNA analysis.

Competing Endogenous RNA of Snail and Zeb1 UTR in Therapeutic Resistance of Colorectal Cancer.

The epithelial-mesenchymal transition (EMT) comprises an important biological mechanism not only for cancer progression but also in the therapeutic resistance of cancer cells. While the importance of the protein abundance of EMT-inducers, such as Snail (SNAI1) and Zeb1 (ZEB1), during EMT progression is clear, the reciprocal interactions between the untranslated regions (UTRs) of EMT-inducers via a competing endogenous RNA (ceRNA) network have received little attention. In this study, we found a synchronized transcript abundance of Snail and Zeb1 mediated by a non-coding RNA network in colorectal cancer (CRC). Importantly, the trans-regulatory ceRNA network in the UTRs of EMT inducers is mediated by competition between tumor suppressive miRNA-34 (miR-34) and miRNA-200 (miR-200). Furthermore, the ceRNA network consisting of the UTRs of EMT inducers and tumor suppressive miRs is functional in the EMT phenotype and therapeutic resistance of colon cancer. In The Cancer Genome Atlas (TCGA) samples, we also found genome-wide ceRNA gene sets regulated by miR-34a and miR-200 in colorectal cancer. These results indicate that the ceRNA networks regulated by the reciprocal interaction between EMT gene UTRs and tumor suppressive miRs are functional in CRC progression and therapeutic resistance.

Metformin and Niclosamide Synergistically Suppress Wnt and YAP in APC-Mutated Colorectal Cancer.

The Wnt and Hippo pathways are tightly coordinated and understanding their reciprocal regulation may provide a novel therapeutic strategy for cancer. Anti-helminthic niclosamide is an effective inhibitor of Wnt and is now in a phase II trial for advanced colorectal cancer (CRC) patients. We found that Axin2, an authentic target gene of canonical Wnt, acts as aYAP phosphorylation activator in APC-mutated CRC. While niclosamide effectively suppresses Wnt, it also inhibits Hippo, limiting its therapeutic potential for CRC. To overcome this limitation, we utilized metformin, a clinically available AMPK activator. This combinatory approach not only suppresses canonical Wnt activity, but also inhibits YAP activity in CRC cancer cells and in patient-derived cancer organoid through the suppression of cancer stemness. Further, combinatory oral administration suppressed in vivo tumorigenesis and the cancer progression of APC-MIN mice models. Our observations provide not only a reciprocal link between Wnt and Hippo, but also clinically available novel therapeutics that are able to target Wnt and YAP in APC-mutated CRC.

Alteration in stemness causes exclusivity between Epstein-Barr virus-positivity and microsatellite instability status in gastric cancer.

BACKGROUND: Gastric cancer (GC) is a leading cause of cancer morbidity and mortality worldwide. This is due to the heterogeneous features of GC, which consist of a diverse molecular phenotype. Epstein-Barr virus (EBV)-positive GC and microsatellite instability (MSI)-high GC encompass similar epigenetic traits, including high levels of DNA methylation in CpG islands; however, EBV-positive and MSI-high GCs are mutually exclusive. We aimed to elucidate the underlying mechanism of this exclusivity. METHODS: We knocked out MLH1 in EBV-positive GC cell lines SNU-719 and NCC24 via CRISPR-Cas9, and evaluated the modified cellular properties in vitro and in vivo. The MSI status of each cell line was screened with two marker capillary electrophoresis, and further diagnosed with five marker capillary electrophoresis and parallel sequencing using 21 markers. RESULTS: Initial evaluation showed that cell growth, migration, invasion, and MSI status were not affected by MLH1 silencing. However, with prolonged passage, GC cell lines gradually gained MSI and NCC24 cells were transformed to EBV-positive/MSI-high GC cells after 12 months. Furthermore, MLH1 silencing reduced tumor stemness in SNU-719 and NCC24 regardless of the MSI status in vitro and in vivo. CONCLUSIONS: Our findings suggest that EBV-positivity and MSI-high status are mutually exclusive due to the immediate disadvantage in tumor stemness when MLH1 is silenced, whereas the establishment of MSI-high status in EBV-positive GCs required a longer period.

Phenotype-based single cell sequencing identifies diverse genetic subclones in CD133 positive cancer stem cells.

Tumor heterogeneity is one of the ongoing huddles in the field of colon cancer therapy. It is evident that there are countless clones which exhibit different phenotypes and therefore, single cell analysis is inevitable. Cancer stem cells (CSCs) are rare cell population within tumor which is known to function in cancer metastasis and recurrence. Although there have been trials to prove intra-tumoral heterogeneity using single cell sequencing, that of CSCs has not been clearly elucidated. Here, we articulate the presence of heterogeneous subclones within CD133 positive cancer stem cells through single cell sequencing. As a proof of principle, we performed phenotype-based high-throughput laser isolation and single cell sequencing (PHLI-seq) of CD133 positive cells in a frozen tumor tissue obtained from a patient with colorectal cancer. The result proved that CD133 positive cells were shown to be heterogeneous both in copy number and mutational profiles. Single cancer stem cell specific mutations such as RNF144A, PAK2, PARP4, ADAM21, HYDIN, KRT38 and CELSR1 could be also detected in liver metastatic tumor of the same patient. Collectively, these data suggest that single cell analysis used to spot subclones with genetic variation within rare population, will lead to new strategies to tackle colon cancer metastasis.

Micellized Protein Transduction Domain-Bone Morphogenetic Protein-7 Efficiently Blocks Renal Fibrosis Via Inhibition of Transforming Growth Factor-Beta-Mediated Epithelial-Mesenchymal Transition.

Tubulointerstitial renal fibrosis is a chronic disease process affecting chronic kidney disease (CKD). While the etiological role of transforming growth factor-beta (TGF-ß) is well known for epithelial-mesenchymal transition (EMT) in chronic kidney disease, effective therapeutics for renal fibrosis are largely limited. As a member of the TGF-ß superfamily, bone morphogenetic protein-7 (BMP-7) plays an important role as an endogenous antagonist of TGF-ß, inhibiting fibrotic progression in many organs. However, soluble rhBMP-7 is hardly available for therapeutics due to its limited pharmacodynamic profile and rapid clearance in clinical settings. In this study, we have developed a novel therapeutic approach with protein transduction domain (PTD) fused BMP-7 in micelle (mPTD-BMP-7) for long-range signaling in vivo. Contrary to rhBMP-7 targeting its cognate receptors, the nano-sized mPTD-BMP-7 is transduced into cells through an endosomal pathway and secreted to the exosome having active BMP-7. Further, transduced mPTD-BMP-7 successfully activates SMAD1/5/8 and inhibits the TGF-ß-mediated epithelial-mesenchymal transition process in vitro and in an in vivo unilateral ureter obstruction model. To determine the clinical relevance of our strategy, we also developed an intra-arterial administration of mPTD-BMP-7 through renal artery in pigs. Interestingly, mPTD-BMP-7 through renal artery intervention effectively delivered into Bowman's space and inhibits unilateral ureter obstruction-induced renal fibrosis in pigs. Our results provide a novel therapeutic targeting TGF-ß-mediated renal fibrosis and other organs as well as a clinically available approach for kidney.

Liquid biopsy-based tumor profiling for metastatic colorectal cancer patients with ultra-deep targeted sequencing.

Analyzing cell-free DNA (cfDNA) as a source of circulating tumor DNA is useful for diagnosing or monitoring patients with cancer. However, the concordance between cfDNA within liquid biopsy and genomic DNA (gDNA) within tumor tissue biopsy is still under debate. To evaluate the concordance in a clinical setting, we enrolled 54 patients with metastatic colorectal cancer and analyzed their plasma cfDNA, gDNA from peripheral blood mononuclear cells (PBMC), and gDNA from available matched tumor tissues using ultra-deep sequencing targeting 10 genes (38-kb size) recurrently mutated in colorectal cancer. We first established a highly reliable cut-off value using reference material. The sensitivity of detecting KRAS hotspot mutations in plasma was calculated as 100%, according to digital droplet PCR. We could selectively detect clinically important somatic alterations with a variant allele frequency as low as 0.18%. We next compared somatic mutations of the 10 genes between cfDNA and genomic DNA from tumor tissues and observed an overall 93% concordance rate between the two types of samples. Additionally, the concordance rate of patients with the time interval between liquid biopsy and tumor tissue biopsy within 6 months and no prior exposure to chemotherapy was much higher than those without. The patients with KRAS mutant fragments in plasma had poor prognosis than those without the mutant fragments (33 months vs. 63 months; p<0.05). Consequently, the profiling with our method could achieve highly concordant results and may facilitate the surveillance of the tumor status with liquid biopsy in CRC patients.

Blood-Based Detection of Colorectal Cancer Using Cancer-Specific DNA Methylation Markers.

Cancer tissues have characteristic DNA methylation profiles compared with their corresponding normal tissues that can be utilized for cancer diagnosis with liquid biopsy. Using a genome-scale DNA methylation approach, we sought to identify a panel of DNA methylation markers specific for cell-free DNA (cfDNA) from patients with colorectal cancer (CRC). By comparing DNA methylomes between CRC and normal mucosal tissues or blood leukocytes, we identified eight cancer-specific methylated loci (ADGRB1, ANKRD13, FAM123A, GLI3, PCDHG, PPP1R16B, SLIT3, and TMEM90B) and developed a five-marker panel (FAM123A, GLI3, PPP1R16B, SLIT3, and TMEM90B) that detected CRC in liquid biopsies with a high sensitivity and specificity with a droplet digital MethyLight assay. In a set of cfDNA samples from CRC patients (n = 117) and healthy volunteers (n = 60), a panel of five markers on the platform of the droplet digital MethyLight assay detected stages I-III and stage IV CRCs with sensitivities of 45.9% and 95.7%, respectively, and a specificity of 95.0%. The number of detected markers was correlated with the cancer stage, perineural invasion, lymphatic emboli, and venous invasion. Our five-marker panel with the droplet digital MethyLight assay showed a high sensitivity and specificity for the detection of CRC with cfDNA samples from patients with metastatic CRC.

NFATC3-PLA2G15 Fusion Transcript Identified by RNA Sequencing Promotes Tumor Invasion and Proliferation in Colorectal Cancer Cell Lines.

PURPOSE: This study was designed to identify novel fusion transcripts (FTs) and their functional significance in colorectal cancer (CRC) lines. MATERIALS AND METHODS: We performed paired-end RNA sequencing of 28 CRC cell lines. FT candidates were identified using TopHat-fusion, ChimeraScan, and FusionMap tools and further experimental validation was conducted through reverse transcription-polymerase chain reaction and Sanger sequencing. FT was depleted in human CRC line and the effects on cell proliferation, cell migration, and cell invasion were analyzed. RESULTS: One thousand three hundred eighty FT candidates were detected through bioinformatics filtering. We selected six candidate FTs, including four inter-chromosomal and two intrachromosomal FTs and each FT was found in at least one of the 28 cell lines. Moreover, when we tested 19 pairs of CRC tumor and adjacent normal tissue samples, NFATC3-PLA2G15 FT was found in two. Knockdown of NFATC3-PLA2G15 using siRNA reduced mRNA expression of epithelial-mesenchymal transition (EMT) markers such as vimentin, twist, and fibronectin and increased mesenchymal-epithelial transition markers of E-cadherin, claudin-1, and FOXC2 in colo-320 cell line harboring NFATC3-PLA2G15 FT. The NFATC3-PLA2G15 knockdown also inhibited invasion, colony formation capacity, and cell proliferation. CONCLUSION: These results suggest that that NFATC3-PLA2G15 FTs may contribute to tumor progression by enhancing invasion by EMT and proliferation.

Three-Dimensional Analysis of Transverse Width of Hard Tissue and Soft Tissue After Mandibular Setback Surgery Using Intraoral Vertical Ramus Osteotomy: A Retrospective Study.

PURPOSE: Some clinicians are concerned that if an intraoral vertical ramus osteotomy (IVRO) is used to position the mandible posteriorly, the proximal segments should be positioned laterally to the distal segment, which could increase the transverse mandibular width, leading to esthetically unfavorable results. This study investigated short- and long-term postoperative transverse mandibular width changes in the soft and hard tissue after IVRO for mandibular prognathism. MATERIALS AND METHODS: The study comprised 44 patients who were treated with mandibular setback surgery using an IVRO. They were categorized into either the facial symmetry group or facial asymmetry group based on their preoperative levels of chin top deviation. Three-dimensional cone-beam computed tomography images were obtained at the preoperative, 1-month postoperative, and 12-month postoperative stages, designated as T1, T2, and T3, respectively. We set hard tissue width 1 (HW1) and hard tissue width 2 (HW2) as the sum of the distance at the bilateral ends of the angle and ramus, respectively, and set soft tissue width 1 (SW1) and soft tissue width 2 (SW2) as the sum of the distance at the bilateral ends of the soft tissue angle and ramus, respectively. RESULTS: Compared with the value at T1, the HW1 value increased by 8.16% (P < .05) and HW2 increased by 4.39% (P > .05) at T2; HW1 increased by 4.35% (P < .05) and HW2 increased by 2.95% (P > .05) at T3. Compared with the value at T1, the SW1 value increased by 2.49% and SW2 increased by 2.50% at T2; however, SW1 decreased by 0.85% and SW2 increased by 0.37% at T3. The soft tissue variations between T1 and T2, as well as between T2 and T3, were statistically significant. However, no significant difference was found between T1 and T3 (P > .05). No difference between the facially symmetrical and asymmetrical groups was found over time for soft and hard tissues (P > .05). CONCLUSIONS: Notably, IVRO does not seem to impact the transverse facial profile and enables reliable prediction of the esthetic results of surgery.

Activation of WNT/ß-catenin signaling results in resistance to a dual PI3K/mTOR inhibitor in colorectal cancer cells harboring PIK3CA mutations.

PIK3CA is a frequently mutated gene in cancer, including about ~15 to 20% of colorectal cancers (CRC). PIK3CA mutations lead to activation of the PI3K/AKT/mTOR signaling pathway, which plays pivotal roles in tumorigenesis. Here, we investigated the mechanism of resistance of PIK3CA-mutant CRC cell lines to gedatolisib, a dual PI3K/mTOR inhibitor. Out of a panel of 29 CRC cell lines, we identified 7 harboring one or more PIK3CA mutations; of these, 5 and 2 were found to be sensitive and resistant to gedatolisib, respectively. Both of the gedatolisib-resistant cell lines expressed high levels of active glycogen synthase kinase 3-beta (GSK3ß) and harbored the same frameshift mutation (c.465_466insC; H155fs*) in TCF7, which encodes a positive transcriptional regulator of the WNT/ß-catenin signaling pathway. Inhibition of GSK3ß activity in gedatolisib-resistant cells by siRNA-mediated knockdown or treatment with a GSK3ß-specific inhibitor effectively reduced the activity of molecules downstream of mTOR and also decreased signaling through the WNT/ß-catenin pathway. Notably, GSK3ß inhibition rendered the resistant cell lines sensitive to gedatolisib cytotoxicity, both in vitro and in a mouse xenograft model. Taken together, these data demonstrate that aberrant regulation of WNT/ß-catenin signaling and active GSK3ß induced by the TCF7 frameshift mutation cause resistance to the dual PI3K/mTOR inhibitor gedatolisib. Cotreatment with GSK3ß inhibitors may be a strategy to overcome the resistance of PIK3CA- and TCF7-mutant CRC to PI3K/mTOR-targeted therapies.

Macrophage migration inhibitory factor promotes resistance to MEK blockade in KRAS mutant colorectal cancer cells.

Although MEK blockade has been highlighted as a promising antitumor drug, it has poor clinical efficacy in KRAS mutant colorectal cancer (CRC). Several feedback systems have been described in which inhibition of one intracellular pathway leads to activation of a parallel signaling pathway, thereby decreasing the effectiveness of single-MEK targeted therapies. Here, we investigated a bypass mechanism of resistance to MEK inhibition in KRAS CRC. We found that KRAS mutant CRC cells with refametinib, MEK inhibitor, induced MIF secretion and resulted in activation of STAT3 and MAPK. MIF knockdown by siRNA restored sensitivity to refametinib in KRAS mutant cells. In addition, combination with refametinib and 4-IPP, a MIF inhibitor, effectively reduced the activity of STAT3 and MAPK, more than single-agent treatment. As a result, combined therapy was found to exhibit a synergistic growth inhibitory effect against refametinib-resistant cells by inhibition of MIF activation. These results reveal that MIF-induced STAT3 and MAPK activation evoked an intrinsic resistance to refametinib. Our results provide the basis for a rational combination strategy against KRAS mutant colorectal cancers, predicated on the understanding of cross talk between the MEK and MIF pathways.