The spectrum of TP53 mutations in Rwandan patients with gastric cancer.

BACKGROUND: Gastric cancer is the sixth most frequently diagnosed cancer and third in causing cancer-related death globally. The most frequently mutated gene in human cancers is TP53, which plays a pivotal role in cancer initiation and progression. In Africa, particularly in Rwanda, data on TP53 mutations are lacking. Therefore, this study intended to obtain TP53 mutation status in Rwandan patients with gastric cancer. RESULTS: Formalin-fixed paraffin-embedded tissue blocks of 95 Rwandan patients with histopathologically proven gastric carcinoma were obtained from the University Teaching Hospital of Kigali. After DNA extraction, all coding regions of the TP53 gene and the exon-intron boundary region of TP53 were sequenced using the Sanger sequencing. Mutated TP53 were observed in 24 (25.3%) of the 95 cases, and a total of 29 mutations were identified. These TP53 mutations were distributed between exon 4 and 8 and most of them were missense mutations (19/29; 65.5%). Immunohistochemical analysis for TP53 revealed that most of the TP53 missense mutations were associated with TP53 protein accumulation. Among the 29 mutations, one was novel (c.459_477delCGGCACCCGCGTCCGCGCC). This 19-bp deletion mutation in exon 5 caused the production of truncated TP53 protein (p.G154Wfs*10). Regarding the spectrum of TP53 mutations, G:C > A:T at CpG sites was the most prevalent (10/29; 34.5%) and G:C > T:A was the second most prevalent (7/29; 24.1%). Interestingly, when the mutation spectrum of TP53 was compared to three previous TP53 mutational studies on non-Rwandan patients with gastric cancer, G:C > T:A mutations were significantly more frequent in this study than in our previous study (p = 0.013), the TCGA database (p = 0.017), and a previous study on patients from Hong Kong (p = 0.006). Even after correcting for false discovery, statistical significance was observed. CONCLUSIONS: Our results suggested that TP53 G:C > T:A transversion mutation in Rwandan patients with gastric cancer is more frequent than in non-Rwandan patients with gastric cancer, indicating at an alternative etiological and carcinogenic progression of gastric cancer in Rwanda.

High Expression of Fas-Associated Factor 1 Indicates a Poor Prognosis in Non-Small-Cell Lung Cancer.

Fas-associated factor 1 (FAF1) is a death-promoting protein identified as an interaction partner of the death receptor Fas. The downregulation and mutation of FAF1 have been reported in a variety of human tumors, but there have been few studies on lung cancer. Here, we investigated the prognostic significance of FAF1 expression in non-small-cell lung cancer (NSCLC), and whether aberrant FAF1 expression may be involved in the pathogenesis and prognosis of NSCLC. FAF1 expression was examined in NSCLC specimens as well as human lung cancer cell lines. In addition, changes in cell viability and apoptosis upon regulating FAF1 expression were investigated in lung cancer cell lines. As a result, high FAF1 expression was significantly associated with a poor prognosis in NSCLC. In lung cancer cell lines, FAF1 downregulation hindered cell viability and tended to promote early apoptosis. In conclusion, this is the first study of the clinical significance of FAF1 in NSCLC, showing that FAF1 overexpression is associated with a poor prognosis in NSCLC and that FAF1 acts as a dangerous factor rather than an apoptosis promoter in NSCLC.

Both MLH1 deficiency and BRAFV600E mutation are a unique characteristic of colorectal medullary carcinoma: An observational study.

Although immunohistochemistry (IHC) for mismatch repair (MMR) proteins (MMR IHC) is used to identify DNA MMR status, universal screening of all patients with colorectal cancer (CRC) using a combination of both MMR IHC and genetic testing for the BRAFV600E mutation is limited in Japan. This study aimed to better understand the histopathological characteristics of CRCs, which exhibit both deficient mismatch repair (dMMR) and BRAFV600E mutation. MMR IHC of formalin-fixed paraffin-embedded tissues from tumor areas obtained from 651 patients with CRC who underwent surgical resection at Hamamatsu University Hospital (Hamamatsu, Japan) between August 2016 and March 2022 were used to evaluate MMR status, which was determined by staining for the expression of 4 MMR proteins (MLH1, MSH2, PMS2, and MSH6). All dMMR tumors were additionally evaluated for BRAFV600 mutation status via Sanger sequencing. Patient clinical characteristics (age, sex, tumor location, size, and tumor pathology) were then classified using their dMMR and BRAFV600 mutation statuses. Among the 651 patients with CRC, 58 carried tumors with dMMR, of which 52 were deficiency in MLH1 (dMLH1). Interestingly, all 16 medullary carcinomas that were analyzed showed characteristics corresponding to the presence of both dMLH1 and BRAFV600E mutation (P = .01). These results suggest that colorectal medullary carcinomas can be diagnosed based on their unique characteristics of harboring the BRAFV600E mutation and exhibiting dMLH1 expression.

DNA methylation status of SHATI/NAT8L promoter in the blood of cigarette smokers.

AIMS: Cigarette smoking is a preventable risk factor for various diseases such as cancer, ischemic stroke, cardiac stroke, and chronic obstructive pulmonary disease. Smoking cessation is of great importance not only for individual smokers but also for social health. Regarding current cessation therapies, the effectiveness of nicotine replacement is limited, and the cost of varenicline medication is considerable. Thus, a method for screening smokers who are responsive to cessation therapy based on the therapeutic effectiveness is required. Peripheral biomarkers reflecting smoking dependence status are necessary to establish a method for achieving effective cessation therapy. METHODS: Methylation status of smokers' blood DNA was evaluated focusing on SHATI/NAT8L, an addiction-related gene. Eight CpG sites in SHATI/NAT8L were quantified by pyrosequencing. RESULTS: There was no difference in the methylation status of this gene between smokers (n = 129) and non-smokers (n = 129) at all CpG sites. No correlations between the methylation status of SHATI/NAT8L and indicators of smoking dependence were found. CONCLUSIONS: Although the present study found no significance in the DNA methylation of SHATI/NAT8L among smokers, the exploration of predictable peripheral biomarkers for the effectiveness of smoking cessation therapy is required.

Lung adenocarcinoma and squamous cell carcinoma difficult for immunohistochemical diagnosis can be distinguished by lipid profile.

In patients with unresectable non-small cell lung cancer, histological diagnosis is frequently based on small biopsy specimens unsuitable for histological diagnosis when they are severely crushed and do not retain their morphology. Therefore, establishing a novel diagnostic method independent of tissue morphology or conventional immunohistochemistry (IHC) markers is required. We analyzed the lipid profiles of resected primary lung adenocarcinoma (ADC) and squamous cell carcinoma (SQCC) specimens using liquid chromatography-tandem mass spectrometry. The specimens of 26 ADC and 18 SQCC cases were evenly assigned to the discovery and validation cohorts. Non-target screening on the discovery cohort identified 96 and 13 lipid peaks abundant in ADC and SQCC, respectively. Among these 109 lipid peaks, six and six lipid peaks in ADC and SQCC showed reproducibility in target screening on the validation cohort. Finally, we selected three and four positive lipid markers for ADC and SQCC, demonstrating high discrimination abilities. In cases difficult to diagnose by IHC staining, [cardiolipin(18:2_18:2_18:2_18:2)-H]- and [triglyceride(18:1_17:1_18:1) + NH4]+ showed the excellent diagnostic ability for ADC (sensitivity: 1.00, specificity: 0.89, accuracy: 0.93) and SQCC (sensitivity: 0.89, specificity: 0.83, accuracy: 0.87), respectively. These novel candidate lipid markers may contribute to a more accurate diagnosis and subsequent treatment strategy for unresectable NSCLC.

TP53 mutations in Romanian patients with colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) has been ranked as the second most deadly cancer and the third most diagnosed cancer cases for the year 2020. Specifically for Romania, the number of CRC-related deaths in 2019 was estimated at 6307 people, with a standardized mortality rate of 33.8 per 100,000 inhabitants. Although the tumor protein 53 (TP53) gene is intensively studied, there are few data on TP53 mutations in Romanian CRC. Furthermore, since genetic alterations may show geographical differences, our study aimed to analyze the clinical status and TP53 somatic variation in Romanian CRC patients. SUBJECTS AND METHODS: DNA from 40 randomly selected cases of CRC was extracted from formalin-fixed paraffin-embedded tissues and sequenced using direct Sanger sequencing techniques, and variants were annotated according to the recommendations of the Human Genome Variation Society. Novel variants were analyzed using MutationTaster2021 to predict their effects. RESULTS: The mean age was 63.6 years (range 33-85 years) with a male to female ratio of 2.3. More than 45% (18/40) had an advanced cancer stage (≥ stage III). Mutations were found in 21/40 cases (52.5%), with one case having two mutations, giving a total of twenty-two mutations in the TP53 coding DNA. These mutations include 3 (13.6%) insertion-deletion mutations, two of which are novel frameshift mutations: c.165delT (in exon 4) and c.928_935dup (in exon 9), both of which are predicted to lead to nonsense-mediated mRNA decay and are classified as deleterious. The remaining 19 (86.36%) were substitution mutations: 1 nonsense and 18 (81.8%) missense mutations, with G > A (n = 7/19; 36.8%) and C > T (n = 6/19; 31.5%) transitions being the most common. The G > T transversion was found in 21.05% (4/19) of the substitution mutations. CONCLUSION: We have described two novel frameshift mutations in TP53. The discovery of novel mutations following the efforts of The Cancer Genome Atlas and other large-scale cancer genome sequencing projects may be further evidence of the heterogeneous nature of mutations in cancer and may indicate that the identification of carcinogenic mutations is not yet saturated. Further sequencing is therefore needed, especially in less studied populations. Importantly, consideration of their geographical environment will shed light on population-specific carcinogenesis.

Lipidomics-based tissue heterogeneity in specimens of luminal breast cancer revealed by clustering analysis of mass spectrometry imaging: A preliminary study.

Cancer tissues reflect a greater number of pathological characteristics of cancer compared to cancer cells, so the evaluation of cancer tissues can be effective in determining cancer treatment strategies. Mass spectrometry imaging (MSI) can evaluate cancer tissues and even identify molecules while preserving spatial information. Cluster analysis of cancer tissues' MSI data is currently used to evaluate the phenotype heterogeneity of the tissues. Interestingly, it has been reported that phenotype heterogeneity does not always coincide with genotype heterogeneity in HER2-positive breast cancer. We thus investigated the phenotype heterogeneity of luminal breast cancer, which is generally known to have few gene mutations. As a result, we identified phenotype heterogeneity based on lipidomics in luminal breast cancer tissues. Clusters were composed of phosphatidylcholine (PC), triglycerides (TG), phosphatidylethanolamine, sphingomyelin, and ceramide. It was found that mainly the proportion of PC and TG correlated with the proportion of cancer and stroma on HE images. Furthermore, the number of carbons in these lipid class varied from cluster to cluster. This was consistent with the fact that enzymes that synthesize long-chain fatty acids are increased through cancer metabolism. It was then thought that clusters containing PCs with high carbon counts might reflect high malignancy. These results indicate that lipidomics-based phenotype heterogeneity could potentially be used to classify cancer for which genetic analysis alone is insufficient for classification.

Clinicopathological Characteristics and Mutational Landscape of APC, HOXB13, and KRAS among Rwandan Patients with Colorectal Cancer.

Cancer research in Rwanda is estimated to be less than 1% of the total African cancer research output with limited research on colorectal cancer (CRC). Rwandan patients with CRC are young, with more females being affected than males, and most patients present with advanced disease. Considering the paucity of oncological genetic studies in this population, we investigated the mutational status of CRC tissues, focusing on the Adenomatous polyposis coli (APC), Kirsten rat sarcoma (KRAS), and Homeobox B13 (HOXB13) genes. Our aim was to determine whether there were any differences between Rwandan patients and other populations. To do so, we performed Sanger sequencing of the DNA extracted from formalin-fixed paraffin-embedded adenocarcinoma samples from 54 patients (mean age: 60 years). Most tumors were located in the rectum (83.3%), and 92.6% of the tumors were low-grade. Most patients (70.4%) reported never smoking, and 61.1% of patients had consumed alcohol. We identified 27 variants of APC, including 3 novel mutations (c.4310_4319delAAACACCTCC, c.4463_4470delinsA, and c.4506_4507delT). All three novel mutations are classified as deleterious by MutationTaster2021. We found four synonymous variants (c.330C>A, c.366C>T, c.513T>C, and c.735G>A) of HOXB13. For KRAS, we found six variants (Asp173, Gly13Asp, Gly12Ala, Gly12Asp, Gly12Val, and Gln61His), the last four of which are pathogenic. In conclusion, here we contribute new genetic variation data and provide clinicopathological information pertinent to CRC in Rwanda.

Evaluation of the widths of the mucosal strips in pathological examination of specimens of endoscopic submucosal dissection for early gastric cancer.

BACKGROUND: Endoscopic submucosal dissection (ESD) is the standard treatment for early gastric cancer in Japan. Pathological evaluation of ESD specimens is considered essential to determine if additional gastrectomy is necessary. Usually, specimens resected by ESD are sliced into 2-3 mm wide sections, and each section is examined for depth of tumor and lymphovascular invasion. Nevertheless, in most cases of additional gastrectomy, lymph node metastasis is not present. Given that there are few-studies on how clinical-decisions based on the pathologic-evaluation-method, in particular the specimen cut-width, influence patient outcomes, we retrospectively evaluated whether reducing the number of cuts to one-half or one-third would result in underestimation of the real need for additional surgery. The effect of the actual cut-width on recommended treatment (referral to operation) and patient-outcomes was also assessed. METHODS: Pathological records of 498 lesions from 439 patients were reviewed and re-evaluated. All pathological descriptions are based on the gastric cancer classification system of the Japanese Gastric Cancer Association, 15th edition. RESULTS: In 5.8% and 8.5% of the total specimens, underdiagnosis of tumor-depth and lymphovascular invasion occurred when the number of sections was reduced to one-half and one-third, respectively. Significantly more submucosal invasions were found in the group in which the cut-with was between 3 and 4 mm than in the group in which the cut width was less than 3 mm. CONCLUSION: Evaluation of the appropriate cut-width is important and should be discussed from the standpoint of labor costs and lost opportunities to search for molecular markers in ESD materials.

Primary Cilia Are Frequently Present in Small Cell Lung Carcinomas but Not in Non-Small Cell Lung Carcinomas or Lung Carcinoids.

Most human malignant neoplasms show loss of primary cilia (PC). However, PC are known to be retained and involved in tumorigenesis in some types of neoplasms. The PC status in lung carcinomas remains largely uninvestigated. In this study, we comprehensively assessed the PC status in lung carcinomas. A total of 492 lung carcinomas, consisting of adenocarcinomas (ACs) (n = 319), squamous cell carcinomas (SCCs) (n = 152), and small cell lung carcinomas (SCLCs) (n = 21), were examined by immunohistochemical analysis using an antibody against ARL13B, a marker of PC. The PC-positive rate was markedly higher in SCLCs (81.0%) than in ACs (1.6%) and SCCs (7.9%). We subsequently performed analyses to characterize the PC-positive lung carcinomas further. PC-positive lung carcinomas were more numerous and had longer PC than normal cells. The presence of PC in these cells was not associated with the phase of the cell cycle. We also found that the PC were retained even in metastases from PC-positive lung carcinomas. Furthermore, the hedgehog signaling pathway was activated in PC-positive lung carcinomas. Because ARL13B immunohistochemistry of lung carcinoids (n = 10) also showed a statistically significantly lower rate (10.0%) of PC positivity than SCLCs, we searched for a gene(s) that might be upregulated in PC-positive SCLCs compared with lung carcinoids, but not in PC-negative carcinomas. This search, and further cell culture experiments, identified HYLS1 as a gene possessing the ability to regulate ciliogenesis in PC-positive lung carcinomas. In conclusion, our findings indicate that PC are frequently present in SCLCs but not in non-SCLCs (ACs and SCCs) or lung carcinoids, and their PC exhibit various specific pathobiological characteristics. This suggests an important link between lung carcinogenesis and PC.

Modification of Grocott's staining procedure with heat treatment and oxidation by periodic acid for mucormycosis in tissue: a method to detect Mucor spp.

The sensitivity of the Grocott-modified Gomori's methenamine-silver nitrate technique for the detection of fungi is sometimes low, especially for Mucor spp. We modified the Grocott technique by replacing chromic acid with periodic acid in the oxidation step. The use of periodic acid instead of chromic acid enhanced the detectability of Mucor spp. in histopathological sections. Other parameters should be assessed with a high number of cases under different conditions. We propose our protocol as one of the options in practice, especially in cases suspected of Mucor spp. infection.

Identifying Active Progeny Virus Particles in Formalin-Fixed, Paraffin-Embedded Sections Using Correlative Light and Scanning Electron Microscopy.

Immunohistochemical analysis of formalin-fixed paraffin-embedded (FFPE) tissue blocks is routinely used to identify virus-infected cells. However, detecting virus particles in FFPE sections using light microscopy is difficult because of the light diffraction resolution limitations of an optical microscope. In this study, light microscopy and field emission scanning electron microscopy were performed to observe 3-dimensional virus particles in FFPE sections in a nondestructive manner using NanoSuit or osmium conductive treatment methods. The virus particles in FFPE sections were immunostained with specific antibodies against the surface antigens of the viral particles and stained with 3,3'-diaminobenzidine. A metal solution (0.2% gold chloride or 2% osmium tetroxide) was applied to enhance the 3,3'-diaminobenzidine-stained area. This procedure is nondestructive for FFPE sections and is a simpler method than transmission electron microscopy. To validate the applicability of this technique, we performed 3-dimensional imaging of the virus particles of different sizes, such as human papillomavirus, cytomegalovirus, and varicella-zoster virus. Furthermore, ultrathin sections from the FFPE sections that were observed to harbor viral particles using field emission scanning electron microscopy were prepared and assessed using transmission electron microscopy. In the correlative areas, transmission electron microscopy confirmed the presence of large numbers of virus particles. These results indicated that the combination of marking viral particles with 3,3'-diaminobenzidine/metal staining and conductive treatment can identify active progeny virus particles in FFPE sections using scanning electron microscopy. This easy correlative imaging of field emission scanning electron microscopy of the identical area of FFPE in light microscopy may help elucidate new pathological mechanisms of virus-related diseases.

Non-CpG sites preference in G:C > A:T transition of TP53 in gastric cancer of Eastern Europe (Poland, Romania and Hungary) compared to East Asian countries (China and Japan).

AIM: Mutation spectrum of TP53 in gastric cancer (GC) has been investigated world-widely, but a comparison of mutation spectrum among GCs from various regions in the world are still sparsely documented. In order to identify the difference of TP53 mutation spectrum in GCs in Eastern Europe and in East Asia, we sequenced TP53 in GCs from Eastern Europe, Lujiang (China), and Yokohama, Kanagawa (Japan) and identified the feature of TP53 mutations of GC in these regions. SUBJECTS AND METHOD: In total, 689 tissue samples of GC were analyzed: 288 samples from East European populations (25 from Hungary, 71 from Poland and 192 from Romania), 268 from Yokohama, Kanagawa, Japan and 133 from Lujiang, Anhui province, China. DNA was extracted from FFPE tissue of Chinese, East European cases; and from frozen tissue of Japanese GCs. PCR products were direct-sequenced by Sanger method, and in ambiguous cases, PCR product was cloned and up to 8 clones were sequenced. We used No. NC_000017.11(hg38) as the reference sequence of TP53. Mutation patterns were categorized into nine groups: six base substitutions, insertion, deletion and deletion-insertion. Within G:C > A:T mutations the mutations in CpG and non-CpG sites were divided. The Cancer Genome Atlas data (TCGA, ver.R20, July, 2019) having somatic mutation list of GCs from Whites, Asians, and other ethnicities were used as a reference for our data. RESULTS: The most frequent base substitutions were G:C > A:T transition in all the areas investigated. The G:C > A:T transition in non-CpG sites were prominent in East European GCs, compared with Asian ones. Mutation pattern from TCGA data revealed the same trend between GCs from White (TCGA category) vs Asian countries. Chinese and Japanese GCs showed higher ratio of G:C > A:T transition in CpG sites and A:T > G:C mutation was more prevalent in Asian countries. CONCLUSION: The divergence in mutation spectrum of GC in different areas in the world may reflect various pathogeneses and etiologies of GC, region to region. Diversified mutation spectrum in GC in Eastern Europe may suggest GC in Europe has different carcinogenic pathway of those from Asia.

Thyroid transcription factor-1 expression in rectal adenocarcinoma metastatic to the lung.

Distinguishing metastatic lung tumors from primary lung cancer is essential for planning the appropriate treatment strategy. Thyroid transcription factor-1 (TTF-1) is a reliable immunohistochemistry (IHC) marker for differentiating between primary lung adenocarcinomas and metastatic lung tumors originating from colorectal adenocarcinomas. Herein, we report a rare case of TTF-1 expression in both the metastatic lung tumor and primary rectal adenocarcinoma. Aside from the similar histological characteristics of both tumors when stained with hematoxylin-eosin, the IHC patterns, including negative results for alveolar epithelium markers (napsin A and CK7) and positive results for intestinal markers (CK20, CDX2, SATB2, and ß-catenin), of the lung tumor and the primary rectal adenocarcinoma strongly supported the final diagnosis. Considering the non-negligible frequency of TTF-1 positivity in colorectal adenocarcinomas, applying the IHC panel including multiple markers for alveolar epithelium and intestinal differentiation, would be helpful to support the diagnosis of metastatic lung tumor from a rectal adenocarcinoma.

Lipid biomarkers that reflect postoperative recurrence risk in lung cancer patients who smoke: a case-control study.

BACKGROUND: The risk of postoperative recurrence is higher in lung cancer patients who smoke than non-smokers. However, objective evaluation of the postoperative recurrence risk is difficult using conventional pathological prognostic factors because of their lack of reproducibility. Consequently, novel objective biomarkers that reflect postoperative risk in lung cancer patients who smoke must be identified. Because cigarette smoking and oncogenesis alter lipid metabolism in lung tissue, we hypothesized that the lipid profiles in lung cancer tissues are influenced by cigarette smoking and can reflect the postoperative recurrence risk in smoking lung cancer patients. This study aimed to identify lipid biomarkers that reflect the smoking status and the postoperative recurrence risk. METHODS: Primary tumor tissues of lung adenocarcinoma (ADC) (n = 26) and squamous cell carcinoma (SQCC) (n = 18) obtained from surgery were assigned to subgroups according to the patient's smoking status. The ADC cohort was divided into never smoker and smoker groups, while the SQCC cohort was divided into moderate smoker and heavy smoker groups. Extracted lipids from the tumor tissues were subjected to liquid chromatography-tandem mass spectrometry analysis. Lipids that were influenced by smoking status and reflected postoperative recurrence and pathological prognostic factors were screened. RESULTS: Two and 12 lipid peaks in the ADC and SQCC cohorts showed a significant positive correlation with the Brinkman index, respectively. Among them, in the ADC cohort, a higher lipid level consisted of three phosphatidylcholine (PC) isomers, PC (14:0_18:2), PC (16:1_16:1), and PC (16:0_16:2), was associated with a shorter recurrence free period (RFP) and a greater likelihoods of progressed T-factor (≥ pT2) and pleural invasion. In the SQCC cohort, a lower m/z 736.5276 level was associated with shorter RFP and greater likelihood of recurrence. CONCLUSIONS: From our data, we propose three PC isomers, PC (14:0_18:2), PC (16:1_16:1), and PC (16:0_16:2), and a lipid peak of m/z 736.5276 as novel candidate biomarkers for postoperative recurrence risk in lung ADC and SQCC patients who are smokers.

Hereditary diffuse gastric cancer in a Japanese family with CDH1 mutation three case reports.

BACKGROUND: Germline pathogenic variants in the E-cadherin gene CDH1 cause hereditary diffuse gastric cancer (HDGC), which is an autosomal dominant cancer syndrome, accounting for 1-3% of all gastric cancers. HDGC harboring a CDH 1 variant is extremely rare in Japan. METHOD: In this study we report the clinical courses of three cases with HDGC from a single Japanese family. RESULTS: The proband exhibited advanced and metastatic gastric cancer, and was found to have a previously reported heterozygous frameshift variant in CDH1 (NM_004360.3:c.1009_1010del:p.Ser337Phefs*12). Five at-risk relatives underwent presymptomatic molecular testing after careful genetic counseling, and three were molecularly diagnosed as positive for the variant. Esophagogastroduodenoscopy was performed in these relatives revealing abnormal small pale mucosal patches, small ulcerative lesion and no abnormal findings. Moreover, random and targeted biopsies were compatible with pathological diagnosis of HDGC in the three cases, all of which underwent total prophylactic gastrectomy. CONCLUSION: It is critical for the assessment and management of HDGC patients to be actively offered a multidisciplinary and familial-oriented approach. Notably, genetic screening in suspected individuals and familial members is a determining piece for a higher detection rate and the identification of clinical relevant mutations in both low and high-incidence gastric cancer countries.

Methylation of CpG island promoters at ZNF625, LONRF2, SDC2 and WDR17 in a patient with numerous non-granular type laterally spreading tumors and colorectal cancer: A case report.

Patients with adenomatous polyposis syndromes such as familial adenomatous polyposis are at higher risk of colorectal cancer, hence continuous management is necessary. However, little is known about the etiology of patients with numerous laterally spreading tumors (LSTs), or how genetic alterations uniquely influence LSTs in colorectal carcinogenesis. The present case report investigated a woman with >150 non-granular type LSTs (LST-NG) and one sigmoid colon cancer. After subtotal colectomy via ileorectal anastomosis, genetic and epigenetic analyses were conducted by comparing the profiles of the patient's normal colonic mucosa, four LST-NG lesions and a cancer lesion. Using customized multigene panel testing, no pathogenic germline mutations were detected, including APC regulator of WNT signaling pathway, but identified a somatic pathogenic variant of APC in one LST-NG lesion, and both TP53 and F-box and WD repeat domain containing 7 somatic mutations in the cancer. Comprehensive genome-wide methylation analysis showed that CpG island promoters at zinc finger protein 625, LON peptidase N-terminal domain and ring finger 2, WD repeat domain 17 and syndecan 2 were methylated in both LST-NG and cancer, which may contribute to colorectal tumorigenesis as early as the LST-NG phase.

Efficacy of HSV-TK/GCV system suicide gene therapy using SHED expressing modified HSV-TK against lung cancer brain metastases.

Lung cancer is one of the most common cancers, and the number of patients with intracranial metastases is increasing. Previously, we developed an enzyme prodrug suicide gene therapy based on the herpes simplex virus thymidine kinase (HSV-TK)/ganciclovir (GCV) system using various mesenchymal stem cells to induce apoptosis in malignant gliomas through bystander killing effects. Here, we describe stem cells from human exfoliated deciduous teeth (SHED) as gene vehicles of the TK/GCV system against a brain metastasis model of non-small cell lung cancer (NSCLC). We introduced the A168H mutant TK (TKA168H) into SHED to establish the therapeutic cells because of the latent toxicity of wild type. SHED expressing TKA168H (SHED-TK) exhibited chemotaxis to the conditioned medium of NSCLC and migrated toward implanted NSCLC in vivo. SHED-TK demonstrated a strong bystander effect in vitro and in vivo and completely eradicated H1299 NSCLC in the brain. SHED-TK cells implanted intratumorally followed by GCV administration significantly suppressed the growth of H1299 and improved survival time. These results indicate that the TKA168H variant is suitable for establishing therapeutic cells and that intratumoral injection of SHED-TK followed by GCV administration may be a useful strategy for therapeutic approaches.