Curative resection via right hemicolectomy and regional lymph node dissection for colonic adenomatous polyposis of unknown etiology with adenocarcinomas localized in the right side of the colon: a case report.

BACKGROUND: APC and MUTYH are both well-known colorectal polyposis causative genes. However, 30-50% of colorectal adenomatous polyposis cases are classified as colonic adenomatous polyposis of unknown etiology and lack identifiable pathogenic variants. Although guidelines recommend total proctocolectomy for colonic adenomatous polyposis of unknown etiology with over 100 adenomas, evidence is lacking. This study presents a unique case of localized colonic adenomatous polyposis of unknown etiology with multiple adenocarcinomas, treated with hemicolectomy and regional lymph node dissection. CASE PRESENTATION: The patient was a 72-year-old woman whose colonoscopy revealed numerous polyps and two adenocarcinomas localized in the right side of the colon, with no lesions in the left side. The patient had no family history of polyposis or colorectal cancer. No extracolonic lesions, enlarged lymph nodes, or distant metastases were found. Considering the patient's age and lesion localization, laparoscopic right hemicolectomy with regional lymph node dissection was performed. Histopathological diagnosis revealed three adenocarcinoma lesions with no lymph node metastasis. The most advanced pathological stage was T2N0M0 Stage I (UICC 8th edition). The patient was alive 5 years postoperatively, without recurrence of cancer or polyposis in the remaining colon and rectum. To diagnose hereditary colorectal cancer/polyposis, a germline multigene panel testing for APC, EPCAM, MBD4, MLH1, MLH3, MSH2, MSH3, MSH6, MUTYH, NTHL1, PMS2, POLD1, POLE, and TP53 was performed using DNA extracted from blood samples: however, no pathogenic variant was detected. Therefore, the patient was diagnosed with colonic adenomatous polyposis of unknown etiology. CONCLUSIONS: In this rare case, colonic adenomatous polyposis of unknown etiology, with numerous adenomatous polyps and multiple adenocarcinomas localized in the right side of the colon, was successfully treated with right hemicolectomy and regional lymph node dissection. Despite genetic analysis, no causative germline variants were identified. Segmental colectomy according to the distribution of polyps might be a curative approach.

Gene-specific ACMG/AMP classification criteria for germline APC variants: Recommendations from the ClinGen InSiGHT Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel.

PURPOSE: The Hereditary Colorectal Cancer/Polyposis Variant Curation Expert Panel (VCEP) was established by the International Society for Gastrointestinal Hereditary Tumours and the Clinical Genome Resource, who set out to develop recommendations for the interpretation of germline APC variants underlying Familial Adenomatous Polyposis, the most frequent hereditary polyposis syndrome. METHODS: Through a rigorous process of database analysis, literature review, and expert elicitation, the APC VCEP derived gene-specific modifications to the ACMG/AMP (American College of Medical Genetics and Genomics and Association for Molecular Pathology) variant classification guidelines and validated such criteria through the pilot classification of 58 variants. RESULTS: The APC-specific criteria represented gene- and disease-informed specifications, including a quantitative approach to allele frequency thresholds, a stepwise decision tool for truncating variants, and semiquantitative evaluations of experimental and clinical data. Using the APC-specific criteria, 47% (27/58) of pilot variants were reclassified including 14 previous variants of uncertain significance (VUS). CONCLUSION: The APC-specific ACMG/AMP criteria preserved the classification of well-characterized variants on ClinVar while substantially reducing the number of VUS by 56% (14/25). Moving forward, the APC VCEP will continue to interpret prioritized lists of VUS, the results of which will represent the most authoritative variant classification for widespread clinical use.

Concordance between microsatellite instability testing and immunohistochemistry for mismatch repair proteins and efficient screening of mismatch repair deficient gastric cancer.

Microsatellite instability (MSI) testing, an established technique that has gained prominence in recent years for its predictive potential regarding the efficacy of immune checkpoint inhibitors, is used to evaluate DNA mismatch repair (MMR) deficiency (dMMR). As with other methods, the immunohistochemistry (IHC) of MMR proteins is also widely adopted. Although both techniques have been validated, their concordance rate remains unknown, particularly regarding non-colorectal cancer. Therefore, the aim of the present study was to explore and elucidate their concordance in the context of gastric cancer (GC). A total of 489 surgically resected primary GC tissues were analyzed to compare the results yielded by the MSI test and those from IHC. Of 488 GC cases, 56 (11.5%) exhibited a loss of MMR proteins, whereas 52 (10.7%) were classified as high-frequency MSI (MSI-H). The concordance rate between these two categories was 99.2%. The microsatellite markers BAT26 and MONO27 demonstrated 100% sensitivity and 99.5% specificity in detecting dMMR GC. In addition, histopathological analysis revealed that MSI-H was more prevalent in GCs exhibiting coexisting Tub2 and Por1 subtypes. However, four discordant cases were observed. All four cases were microsatellite-stable cases but exhibited loss of MLH1 protein expression with hypermethylation of the MLH1 promoter. The results of the present study highlight that while there is a strong concordance between MSI and IHC testing results for determining dMMR status, IHC testing may offer superior efficacy in detecting dMMR.

Identification of Lynch syndrome-associated DNA mismatch repair-deficient bladder cancer in a Japanese hospital-based population.

BACKGROUND: The prevalence of Lynch syndrome (LS)-associated DNA mismatch repair (MMR)-deficient bladder cancer (BC) has scarcely been investigated. METHODS: Immunohistochemistry for four MMR proteins (MLH1, MSH2, MSH6, and PMS2) was performed in formalin-fixed paraffin-embedded (FFPE) sections prepared from the resected specimens of 618 consecutive newly diagnosed BC cases. Genetic/epigenetic analyses were performed in patients displaying the loss of any MMR proteins in the tumor. RESULTS: Of the 618 patients, 9 (1.5%) showed the loss of MMR protein expression via immunohistochemistry; specifically, 3, 3, 2, and 1 patients displayed the loss of MLH1/PMS2, PMS2, MSH6, and MSH2/MSH6, respectively. All nine patients were male with a median age of 68 years (63-79 years). One had been previously diagnosed as having LS with an MSH2 variant. Genetic testing demonstrated the presence of a pathogenic PMS2 variant (n = 1), a variant of uncertain significance in MSH2 (n = 1), and no pathogenic germline variants of the MMR genes (n = 1). One patient with MSH6-deficient BC did not complete the genetic testing because of severe degradation of DNA extracted from the FFPE specimen, but the patient was strongly suspected to have LS because of their history of colon cancer and MSH6-deficient upper urinary tract cancer. There remained a possibility that the remaining four patients who refused genetic testing had LS. CONCLUSIONS: The prevalence of LS-associated MMR-deficient BC was estimated to be 0.6-1.1% among unselected BC cases.

Long-term efficacy of immune checkpoint inhibitors in non-small cell lung cancer patients harboring MET exon 14 skipping mutations.

INTRODUCTION: MET exon 14 skipping mutation, observed in 3-4% of non-small cell lung cancer (NSCLC), is emerging as a targetable alteration. In recent years, immune checkpoint inhibitors (ICI) have been effective in treating several NSCLCs. Our research aimed to investigate the characteristics of patients with NSCLCs harboring MET exon 14 mutations and their response to ICI in Japan. METHODS: Among the 1954 consecutive NSCLCs diagnosed at Saitama Cancer Center between 2010 and 2019, MET exon 14 skipping mutations were detected in 68 (3.5%) NSCLCs. We evaluated their characteristics such as programmed cell death ligand 1 (PD-L1) expression. RESULTS: Median age of patients with NSCLCs harboring MET exon 14 skipping mutations was 73 years. PD-L1 was highly expressed in 17 (70.8%) of the 24 patients examined. Seven patients received ICI monotherapy, and three out of seven had a remarkable treatment response, resulted in objective response rate (ORR) of 42.9% and progression-free survival of 24.7 months. Three patients with donor splice-site mutations showed a long-term treatment response, despite the fact that two with acceptor splice-site mutations demonstrated no response and experienced early disease progression with ICI monotherapy. CONCLUSION: Our results indicated that patients with NSCLCs harboring MET exon 14 mutations presented with a high rate of positive PD-L1 expression. ICI treatment showed a high ORR and long-term efficacy for NSCLCs harboring MET exon 14 mutations. Variants of MET exon 14 splice-site mutations may be associated with ICI response.

SVA retrotransposon insertion in exon of MMR genes results in aberrant RNA splicing and causes Lynch syndrome.

Lynch syndrome is an autosomal dominant hereditary cancer syndrome in which many cancers develop, the main one being colorectal cancer. Germline pathogenic variants in one of four mismatch repair (MMR) genes are known to be causative of this disease. Accurate diagnosis using genetic testing can greatly benefit the health of those affected. Recently, owing to the improvement of sequence techniques, complicated variants affecting the functions of MMR genes were discovered. In this study, we analyzed insertions of a retrotransposon-like sequence in exon 5 of the MSH6 gene and exon 3 of the MSH2 gene found in Japanese families suspected of having Lynch syndrome. Both of these insertions induced aberrant splicing, and these variants were successfully identified by mRNA sequencing or visual observation of mapping results, although a standard DNA-seq analysis pipeline failed to detect them. The insertion sequences were ~2.5 kbp in length and were found to have the structure of an SVA retrotransposon (SVA). One SVA sequence was not present in the hg19 or hg38 reference genome, but was in a Japanese-specific reference sequence (JRGv2). Our study illustrates the difficulties of identifying SVA insertions in disease genes, and that the possibility of polymorphic insertions should be considered when analyzing mobile elements.

Quantitative evaluation of MSI testing using NGS detects the imperceptible microsatellite changed caused by MSH6 deficiency.

Microsatellite instability (MSI) is an effective biomarker for diagnosing Lynch syndrome (LS) and predicting the responsiveness of cancer therapy. MSI testing is conventionally performed by capillary electrophoresis, and MSI status is judged by visual assessment of allele size change. Here, we attempted to develop a quantitative evaluation model of MSI using next-generation sequencing (NGS). Microsatellite markers were analyzed in tumor and non-tumor tissues of colorectal cancer patients by NGS after a single multiplex polymerase chain reaction amplification. The read counts corresponding to microsatellite loci lengths were calculated independently of mapping against a reference genome, and their distribution was digitized by weighted mean. Weighted mean differences between tumor and non-tumor samples with different MSI status were assessed, and cut-off values for each marker in the discovery cohort were determined. Each microsatellite maker was defined as unstable if the weighted mean difference was greater than the cut-off value. In the discovery cohort, the evaluation model demonstrated sensitivity and specificity of 100% for all markers. In the validation cohort, MSI status determined by the new model was consistent with the outcome of the conventional method in 29/30 cases (97%). The single inconsistent case was classified as low-frequency MSI by the conventional method but considered MSI-high by NGS. Genetic testing for mismatch repair genes revealed a pathogenic variant in MSH6 in the discordant case. We successfully developed a quantitative evaluation method for determining MSI status using NGS. This is a robust and sensitive method and could improve LS diagnosis.

Prevalence of Lynch syndrome among patients with upper urinary tract carcinoma in a Japanese hospital-based population.

BACKGROUND: The prevalence of Lynch syndrome and the use of universal tumor screening to identify Lynch syndrome among unselected patients with upper urinary tract urothelial carcinoma, which is associated with Lynch syndrome, have not been closely investigated yet. METHODS: A total of 166 tumors from 164 upper urinary tract urothelial carcinoma patients were tested for microsatellite instability and expression of mismatch repair proteins (MLH1, MHS2, MSH6 and PMS2) by immunohistochemistry. Genetic testing was performed for patients suspected of having Lynch syndrome. Clinicopathological factors, including familial and personal cancer history associated with mismatch repair deficiency, were evaluated. RESULTS: The frequency of high-level microsatellite instability and loss of at least one mismatch repair protein was 2.4% (4/164); the microsatellite instability and immunohistochemistry results showed complete concordance. Of these four patients, three were genetically proven to have Lynch syndrome, while the remaining one was highly suggestive for Lynch syndrome based on their personal cancer history. Univariate analysis showed that age<70 years (P = 0.04), ureter as the tumor location (P = 0.052), previous history/synchronous diagnosis of colorectal cancer (P < 0.01) and fulfillment of the criteria per the revised Bethesda guideline (P < 0.01) tended to be or were significantly associated with high-level microsatellite instability/mismatch repair loss. CONCLUSIONS: The prevalence of Lynch syndrome among unselected upper urinary tract urothelial carcinoma patients was at least 1.8% in our study population. The screening efficacies of the microsatellite instability test and immunohistochemistry appear equivalent. Universal tumor screening may be a valid approach; however, selective screening methods that consider factors associated with mismatch repair loss/high-level microsatellite instability tumors require further investigation.

Development of metachronous rectal cancers in a young man with dyskeratosis congenita: a case report.

BACKGROUND: DKC1 (dyskerin pseudouridine synthase 1) is a causative gene for X-linked dyskeratosis congenita. Approximately 8% of patients with dyskeratosis congenita have malignancy, but information about the development of malignancy in patients with dyskeratosis congenita is limited. CASE PRESENTATION: A young Japanese patient with bone marrow failure developed metachronous rectal adenocarcinomas at the ages of 16 and 18 years. He had no family history of cancer. Microsatellite instability testing with rectal tumor tissue demonstrated low-level microsatellite instability. To clarify whether any cancer susceptibility genes were involved in the development of rectal cancer, RNA sequencing was performed. Cancer-related genes were assessed, and a c.361A>G (p.Ser121Gly) germline variant was detected in DKC1. The same missense variant was previously reported in two patients with dyskeratosis congenita as a pathogenic variant, but those patients did not develop malignancies. CONCLUSIONS: Our patient developed rectal cancer at an early age of onset compared with the previously reported typical onset age of patients with dyskeratosis congenita. DKC1 might be involved in predisposition to colorectal cancer in young adulthood; therefore, appropriate surveillance may be considered.

The single-base-pair deletion, MSH2 c.2635-3delC affecting intron 15 splicing can be a cause of Lynch syndrome.

The proband was a 62-year-old man with ureter cancer. He had a history of metachronous colorectal and gastric cancer. Immunohistochemical staining showed the absence of both MSH2 and MSH6 proteins in the ureter cancer and other available cancer tissue specimens. Genetic testing was conducted to identify the causative genes of hereditary gastrointestinal cancer syndromes including mismatch repair genes. We detected a germline variant, c.2635-3delC, within the splice acceptor site of exon 16, in the MSH2 gene. To investigate whether this variant affected splicing of the gene, RNA sequencing was performed using blood samples. We observed a substantial amount of the transcripts that lacked proper splicing of intron 15 in the indexed case, whereas, a very low amount of such aberrant transcripts was detected in the controls, strongly indicating an association between the variant and splicing defect. These results indicate that MSH2 c.2635-3delC affects normal splicing and might be a cause of Lynch syndrome.

Predictive model for high-frequency microsatellite instability in colorectal cancer patients over 50 years of age.

Microsatellite instability (MSI) is an important biomarker for screening for Lynch syndrome, and also of response to immune checkpoint inhibitors. The aim of this study is to create a predictive model to determine which elderly patients with colorectal cancer (CRC) should undergo MSI and/or immunohistochemistry testing on the basis of clinicopathological data. We analyzed a test cohort of CRC patients aged ≥50 years (n = 2219) by multivariate logistic regression analyses to identify predictors of high-frequency MSI (MSI-H). The created prediction model was validated in an external cohort (n = 992). The frequency of MSI-H was 5.5% among CRC patients aged ≥ 50 years. The following five predictors of MSI-H were identified in the test cohort: female (1 point), mucinous component (2 points), tumor size ≥ 60 mm (2 points), location in proximal colon (3 points), and BRAF mutation (6 points). The area under curve (AUC) in the receiver-operating characteristic (ROC) analysis of this prediction model was 0.832 (95% confidence interval: 0.790-0.874). The sensitivity and specificity were 74.4% and 77.7%, respectively, for a cut-off score of 4 points. The receiver-operating characteristic curve of the validation cohort also showed an AUC of 0.856 (95% CI: 0.806-0.905). This prediction model is useful to select elderly CRC patients who should undergo MSI testing, and who may benefit from treatment with 5-FU-based adjuvant chemotherapy and cancer immunotherapy.

Routine genetic testing of lung cancer specimens derived from surgery, bronchoscopy and fluid aspiration by next generation sequencing.

After the development of EGFR tyrosine kinase inhibitors (TKIs), genetic testing of EGFR became required for effective treatment of lung cancer. Initially, the testing was conducted separately for each mutated region. However, many EGFR mutations have since been identified that determine the efficacy of EGFR-TKIs. Therefore, genetic testing of EGFR by next generation sequencing (NGS) may be a suitable strategy for lung cancer. Here we examined the applicability of the NGS method in regard to sensitivity, time and cost. A total of 939 specimens were obtained from 686 lung cancer patients at our hospital. DNA and RNA were simultaneously extracted from specimens derived from surgery, bronchoscopy, and fluid aspiration. Specimens included cerebrospinal fluid, pleural effusion, abdominal fluid, and pericardial effusion. From RNA, target regions (EGFR, KRAS, ALK fusion and RET fusion) were enriched by RT-PCR and sequenced with MiSeq. From DNA, PCR or PCR-RFLP conventional methods were performed. NGS and conventional methods were carried out routinely per week. Among the total 939 specimens, 38 specimens could not be examined with NGS. Among these, 34 specimens were analyzed by conventional testing with simultaneously extracted DNA. The remaining four specimens could not be tested with either method. Compared with the conventional method, the concordance rate of mutations was 99% (892/901), excluding specimens with NGS failure. The time period required from processing of specimens to results was 4 days, and the cost per sample was sufficiently low. In conclusion, the genetic testing with NGS method was useful for lung cancer treatment. The cost, sensitivity and time were able to tolerate routine examinations.

Metastatic Pattern of Stage IV Colorectal Cancer with High-Frequency Microsatellite Instability as a Prognostic Factor.

BACKGROUND: A recent clinical trial on the immune check-point inhibitor pembrolizumab demonstrated that microsatellite instability (MSI) is a good biomarker for response to this inhibitor. However, clinicopathological features of advanced colorectal cancer (CRC) with high-frequency MSI (MSI-H) are unclear. PATIENTS AND METHODS: A total of 2,439 surgically resected CRC tissues were analyzed for MSI status, and mutational status of V-Ki-Ras2 Kirsten rat sarcoma 2 viral oncogene homolog (KRAS), neuroblastoma RAS viral oncogene homolog (NRAS) and v-Raf murine sarcoma viral oncogene homolog B (BRAF). Stage IV cases were selected, and clinical and molecular features were evaluated. RESULTS: There was no significant survival difference observed between MSI-H CRC and microsatellite-stable (MSS) CRC in patients with stage IV disease (3.92 vs. 2.50 years; p=0.766). However, hematogenous and lymphogenous metastasis-dominant CRC with MSI-H demonstrated poor prognosis, whereas peritoneal metastasis-dominant CRC with MSI-H demonstrated good prognosis, (1.33 vs. 5.2 years; p=0.006). CONCLUSION: Prognosis of stage IV CRC with MSI-H depended on the metastatic pattern. These findings provide useful information for the adaptation of CRC immunotherapy.

High concordance rate of KRAS/BRAF mutations and MSI-H between primary colorectal cancer and corresponding metastases.

Genetic testing is needed for the treatment of colorectal cancer (CRC), especially molecular-targeted therapy. The effects of anti-EGFR therapy and prognosis are affected by the presence of KRAS mutations. However, whether primary CRC or metastatic tissues are appropriate in the analysis is still unclear. In the present study, we assessed the concordance of KRAS/BRAF mutation status and microsatellite instability (MSI) in primary CRC and corresponding metastases. This study enrolled 457 patients with surgically resected primary and corresponding metastatic CRC (499 synchronous metastases and 57 metachronous metastases) and seven local recurrences, and KRAS/BRAF mutation and MSI status were analysed for these tumours. The concordance rates of KRAS mutation, BRAF mutation, wild-type, MSI-H and MSS between primary CRC and corresponding metastases were 93.9% (214/228), 100% (30/30), 99.3% (304/306), 87.5% (21/24) and 100% (137/137), respectively. These high concordance rates were not different between synchronous and metachronous metastases. In conclusion, a high concordance of KRAS/BRAF mutation status and MSI status was observed between primary CRC and corresponding metastases in this study. Either primary CRC or metastatic tissues can be used for testing KRAS/BRAF mutation status and MSI status.

Cytokeratin 13, Cytokeratin 17, Ki-67 and p53 Expression in Upper Layers of Epithelial Dysplasia Surrounding Tongue Squamous Cell Carcinoma.

Early detection of oral squamous cell carcinoma (OSCC) improves its prognosis and aids in selecting the appropriate treatment, which may also have a positive effect on quality of life. Early detection, therefore, is an important issue in the treatment of this disease. The purpose of this study was to investigate expression of cytokeratin 13 (CK13), CK17, Ki-67 and p53 as potential markers of tongue SCC. Five areas in 12 specimens were examined: the upper and lower layers of normal epithelium; those of dysplastic epithelial tissue surrounding the cancerous lesion; and the lesion itself. Strong expression of each of the following mRNAs and proteins was observed; CK13 in upper layers of normal epithelium; Ki-67 and p53 in lower layers of normal epithelium; CK13 and CK17 in upper layer of epithelial dysplasia; and CK17, Ki-67, and p53 in lower layer of epithelial dysplasia and cancerous lesions. These results indicate that the characteristic pattern of expression of CK13 and CK17 differs between normal and dysplastic oral epithelium. Oral epithelial dysplasia adjacent to OSCC has high malignant potential, and is similar to early-stage OSCC. This suggests that evaluation of these markers could be a useful secondary procedure for improving detection of early-stage OSCC.

Localization and osteoblastic differentiation potential of neural crest-derived cells in oral tissues of adult mice.

In embryos, neural crest cells emerge from the dorsal region of the fusing neural tube and migrate throughout tissues to differentiate into various types of cells including osteoblasts. In adults, subsets of neural crest-derived cells (NCDCs) reside as stem cells and are considered to be useful cell sources for regenerative medicine strategies. Numerous studies have suggested that stem cells with a neural crest origin persist into adulthood, especially those within the mammalian craniofacial compartment. However, their distribution as well as capacity to differentiate into osteoblasts in adults is not fully understood. To analyze the precise distribution and characteristics of NCDCs in adult oral tissues, we utilized an established line of double transgenic (P0-Cre/CAG-CAT-EGFP) mice in which NCDCs express green fluorescent protein (GFP) throughout their life. GFP-positive cells were scattered like islands throughout tissues of the palate, gingiva, tongue, and buccal mucosa in adult mice, with those isolated from the latter shown to form spheres, typical cell clusters composed of stem cells, under low-adherent conditions. Furthermore, GFP-positive cells had markedly increased alkaline phosphatase (a marker enzyme of osteoblast differentiation) activity and mineralization as shown by alizarin red staining, in the presence of bone morphogenetic protein (BMP)-2. These results suggest that NCDCs reside in various adult oral tissues and possess potential to differentiate into osteoblastic cells. NCDCs in adults may be a useful cell source for bone regeneration strategies.

Expression of BMI1 and ZEB1 in epithelial-mesenchymal transition of tongue squamous cell carcinoma.

Epithelial-mesenchymal transition (EMT) is a crucial event required for the invasion and progression of carcinogenesis, inducing stem-like properties in epithelial cells. In the present study, the expression of BMI1, which controls self-renewal in stem cells, as well as that of ZEB1, a transcription factor that regulates EMT, was evaluated for its role in EMT and the carcinogenic processes of tongue squamous cell carcinoma (TSCC). Collagen invasion assays using two TSCC cells and 64 tongue specimens (32 carcinomas and 32 dysplasias) were employed and analyzed in the present study. We assessed the protein and mRNA expression levels of BMI1, ZEB1, vimentin and E-cadherin in the two cell lines and tumor tissues. The protein and mRNA expression of BMI1 and ZEB1 occurred at the invasion of TSCC. The elevated levels of BMI1 and ZEB1 were accompanied by the downregulation of E-cadherin and upregulation of vimentin at the invasive front, indicative of EMT in vitro and in vivo. The results showed that BMI1 and ZEB1 are important factors in association with the promotion of EMT and invasion of TSCC.

Potential role of hematopoietic pre-B-cell leukemia transcription factor-interacting protein in oral carcinogenesis.

BACKGROUND: Hematopoietic pre-B-cell leukemia transcription factor-interacting protein (HPIP) is a corepressor of pre-B-cell leukemia homeobox (PBX) 1 and is known to play a role in hematopoiesis. Recently, HPIP was demonstrated to promote breast cancer cell proliferation and hepatocellular carcinoma growth. Moreover, it has been revealed that homeobox and PBX proteins, the expression of which is regulated by HPIP, play key roles in cancer of various organs, including oral squamous cell carcinoma (OSCC). Nevertheless, there has not been any study regarding the role of HPIP in OSCC. This study investigated the expression of HPIP in normal oral mucosa, epithelial precursor lesion (OEPL), and OSCC, and the functional roles of HPIP in OSCC cells and normal keratinocytes. MATERIALS AND METHODS: Immunohistochemical analysis of HPIP, Ki-67, and involucrin was performed in OSCC specimens, and the change in involucrin expression following RNA interference treatment against HPIP was examined by quantitative RT-PCR and Western blot analysis in SCC9 and NHEK cells undergoing extracellular calcium-induced differentiation. Matrigel transwell and cell proliferation assays for both cell lines transfected with HPIP siRNA were also conducted. RESULTS: HPIP expression increased in OEPL and OSCC specimens. In vitro analysis revealed that HPIP suppressed differentiation and proliferation of SCC9 cells and transwell migration of NHEK cells, while HPIP promoted invasion of SCC9 and proliferation of NHEK cells. However, HPIP has no significant effect on NHEK cell differentiation. CONCLUSION: HPIP may play a critical role in oral carcinogenesis and is thus a potential target for anticancer therapy, with particular emphasis on its involvement in differentiation and migration/metastasis.

ANGPTL4 regulates the metastatic potential of oral squamous cell carcinoma.

Lymph node metastasis is a major factor for poor prognosis in oral squamous cell carcinoma (OSCC). However, the molecular mechanisms of lymph node metastasis are unclear. We determined that angiopoietin-like protein 4 (ANGPTL4) mRNA and protein expression were increased in OSCC cells established from the primary site in metastatic cases. In addition, ANGPTL4 expression in biopsy specimens was correlated with the presence of lymph node metastasis. Therefore, our initial findings suggest that OSCC cells expressing ANGPTL4 may possess metastatic ability. Furthermore, cell culture supernatants from OSCC cells that metastasized to the lymph node contain ANGPTL4 and promote invasive ability. These findings suggest that secreted ANGPTL4 may affect the invasive ability of OSCC. Moreover, the rates of positive ANGPTL4 expression at the primary site were significantly higher in the lymph node metastasis group. These results demonstrate that ANGPTL4 contributes to OSCC metastasis by stimulating cell invasion. Therefore, ANGPTL4 is a potential therapeutic target for preventing cancer metastasis.

Inverse effect of mucinous component on survival in stage III colorectal cancer.

BACKGROUND: Although mucinous adenocarcinoma (MAC) is has been recognized as a separate entity in colorectal cancer (CRC), adenocarcinoma with a mucinous component (ACM) remains poorly understood. METHODS: The association of MAC and ACM with disease-free survival (DFS) and overall survival (OS) was examined using the Cox proportional hazard model in 425 consecutive stage III CRCs. RESULTS: Compared with conventional adenocarcinoma (CAC), patients with MAC exhibited independently worse DFS (hazard ratio [HR], 2.64; 95% CI, 1.21-5.80; P = 0.014) and OS (HR, 3.56; 95% CI, 1.53-8.30; P = 0.003). Unexpectedly, ACM was significantly associated with worse OS than CAC (P = 0.002), despite having a similar DFS to CAC. Further, ACM patients after recurrence exhibited significantly worse OS than CAC patients (P < 0.001), similar to MAC. CONCLUSIONS: Although ACM is similar to CAC with regard to estimated risk of recurrence, the outcome is extremely poor once recurrence occurs and is identical to MAC; one of the most aggressive phenotypes of stage III CRC. Thus, both MAC and ACM are adverse prognostic factors for OS.