Alteration of mitochondrial DNA sequence and copy number in nasal polyp tissue

Mitochondrial DNA Mutation Analysis in Breast Cancer: Shifting From Germline Heteroplasmy Toward Homoplasmy in Tumors

Studies have suggested a potential role of somatic mitochondrial mutations in cancer development. To analyze the landscape of somatic mitochondrial mutation in breast cancer and to determine whether mitochondrial DNA (mtDNA) mutational burden is correlated with overall survival (OS), we sequenced whole mtDNA from 92 matched-paired primary breast tumors and peripheral blood. A total of 324 germline variants and 173 somatic mutations were found in the tumors. The most common germline allele was 663G (12S), showing lower heteroplasmy levels in peripheral blood lymphocytes than in their matched tumors, even reaching homoplasmic status in several cases. The heteroplasmy load was higher in tumors than in their paired normal tissues. Somatic mtDNA mutations were found in 73.9% of breast tumors; 59% of these mutations were located in the coding region (66.7% non-synonymous and 33.3% synonymous). Although the CO1 gene presented the highest number of mutations, tRNA genes (T,C, and W), rRNA 12S, and CO1 and ATP6 exhibited the highest mutation rates. No specific mtDNA mutational profile was associated with molecular subtypes of breast cancer, and we found no correlation between mtDNA mutational burden and OS. Future investigations will provide insight into the molecular mechanisms through which mtDNA mutations and heteroplasmy shifting contribute to breast cancer development.

Janus nanozyme–drug nanosystems for synergistic anti-inflammatory treatment of nasal polyps

The multifunctional Au–CeO₂ JNPs as a nanozyme–drug nanosystem have been first explored for CT imaging and synergistic anti-inflammatory treatment of nasal polyps.

Detection of novel mitochondrial mutations in cytochrome C oxidase subunit 1 (COX1) in patients with familial adenomatous polyposis (FAP)

BACKGROUND

Familial adenomatous polyposis (FAP) is an Autosomal dominant inherited disorder and a rare form‌ of colorectal cancer (CRC) that is characterized by the development of hundreds to thousands of adenomas in the rectum and colon. Mostly, cancers develop after the advent of the polyps. It appears in both sexes evenly, and the occurrence of the disease is in the second decade of life. Mitochondrial genome mutations have been reported with a variety of Tumors, but the precise role of these mutations in the pathogenicity and tumor progression is not exactly clear. Cytochrome c oxidase subunit I (COX1) is the terminal enzyme of the mitochondrial respiratory chain. The present study aims at assessing the occurrence of mtDNA mutations in COX1 gene in FAP patients and attempts to find out the cause and effect relationship between mitochondrial mutations and tumor progression.

METHODS

In this study, 56 FAP patients were investigated for the presence of the mutations in mitochondrial COX1 coding gene by PCR and sequencing analysis. All sequences that differed from the revised Cambridge Reference Sequence (rCRS) were classified as missense/ nonsense or silent mutations. Functional genomic studies using Bio-informatics tools were performed on the founded mutations to understand the downstream alterations in structure and function of protein.

RESULTS

We identified 38 changes in the COX1 gene in patients with FAP symptoms. Most of them were heteroplasmic changes of missense type (25/38). Tree of the changes (G6145A, C6988A, and T7306G) were nonsense mutations and had not been reported in the literature before. Our results of bioinformatics predictions showed that the identified mutations can affect mitochondrial functions, especially if the conservative domain of the protein is concerned.

CONCLUSION

Our findings indicate a high frequency of mtDNA mutations in all of the FAP cases compared to matched controls. These data significantly enhance our understanding of how such mutations contribute to cancer pathologies and develop the cancer treatment methods by new diagnostic biomarkers, and new drugs for gene therapy.

Spectrum of mitochondrial genome instability and implication of mitochondrial haplogroups in Korean patients with acute myeloid leukemia

Background

Mitochondrial DNA (mtDNA) mutations may regulate the progression and chemosensitivity of leukemia. Few studies regarding mitochondrial aberrations and haplogroups in acute myeloid leukemia (AML) and their clinical impacts have been reported. Therefore, we focused on the mtDNA length heteroplasmies minisatellite instability (MSI), copy number alterations, and distribution of mitochondrial haplogroups in Korean patients with AML.

Methods

This study investigated 74 adult patients with AML and 70 controls to evaluate mtDNA sequence alterations, MSI, mtDNA copy number, haplogroups, and their clinical implications. The hypervariable (HV) control regions (HV1 and HV2), tRNA^leu1gene, and cytochrome b gene of mtDNA were analyzed. Two mtDNA minisatellite markers, 16189 poly-C (¹⁶¹⁸⁴CCCCCTCCCC¹⁶¹⁹³, 5CT4C) and 303 poly-C (³⁰³CCCCCCCTCCCCC³¹⁵, 7CT5C), were used to examine the mtDNA MSI.

Results

In AML, most mtDNA sequence variants were single nucleotide substitutions, but there were no significant differences compared to those in controls. The number of mtMSI patterns increased in AML. The mean mtDNA copy number of AML patients increased approximately 9-fold compared to that of controls (P<0.0001). Haplogroup D4 was found in AML with a higher frequency compared to that in controls (31.0% vs. 15.7%, P=0.046). None of the aforementioned factors showed significant impacts on the outcomes.

Conclusion

AML cells disclosed more heterogeneous patterns with the mtMSI markers and had increased mtDNA copy numbers. These findings implicate mitochondrial genome instability in primary AML cells. Therefore, mtDNA haplogroup D4 might be associated with AML risk among Koreans.

Clinicopathological Implications of Mitochondrial Genome Alterations in Pediatric Acute Myeloid Leukemia

Background

To the best of our knowledge, the association between pediatric AML and mitochondrial aberrations has not been studied. We investigated various mitochondrial aberrations in pediatric AML and evaluated their impact on clinical outcomes.

Methods

Sequencing, mitochondrial DNA (mtDNA) copy number determination, mtDNA 4,977-bp large deletion assessments, and gene scan analyses were performed on the bone marrow mononuclear cells of 55 pediatric AML patients and on the peripheral blood mononuclear cells of 55 normal controls. Changes in the mitochondrial mass, mitochondrial membrane potential, and intracellular reactive oxygen species (ROS) levels were also examined.

Results

mtDNA copy numbers were about two-fold higher in pediatric AML cells than in controls (P<0.0001). Furthermore, a close relationship was found between mtDNA copy number tertiles and the risk of pediatric AML. Intracellular ROS levels, mitochondrial mass, and mitochondrial membrane potentials were all elevated in pediatric AML. The frequency of the mtDNA 4,977-bp large deletion was significantly higher (P< 0.01) in pediatric AML cells, and pediatric AML patients harboring high amount of mtDNA 4,977-bp deletions showed shorter overall survival and event-free survival rates, albeit without statistical significance.

Conclusions

The present findings demonstrate an association between mitochondrial genome alterations and the risk of pediatric AML.

Variable alterations of mitochondrial microsatellite instability and DNA copy number in pulmonary hamartomas

BACKGROUND

The genetic alteration of mitochondrial DNA has been regarded as an important step in the development of several human tumors.

OBJECTIVE

The purpose of this study was to identify frequency of mitochondrial microsatellite instability (mtMSI) and alterations in mitochondrial DNA copy number (mtCN) in pulmonary hamartoma.

METHODS

DNA was isolated from tumor tissue and matched non-tumor tissue in 30 patients with pulmonary hamartoma. BAT 25 and 26 were used as nucleus MSI (nMSI) markers, and (C)n and (CA)n in D-loop were used as mtMSI markers. MtCNs were quantified using a competitive quantitative real-time polymerase chain reaction.

RESULTS

nMSI was detected in 5 patients (23.8%) and mtMSI was detected in 2 patients (9.5%) of total 21 hamartoma. There were 14 patients (46.7%), 2 patients (6.7%), and a further 14 patients (46.7%) in the decreased, no change, and increased mtCN groups, respectively. The mean relative mtCN were 0.4 ± 0.3 in the decreased and 3.9 ± 5.1 in the increased mtCN groups, respectively.

CONCLUSIONS

nMSI was more frequently appeared than mtMSI in hamartomas, and we also found measurements of mtCNs in patients with pulmonary hamartoma to be extremely variable without any characteristic pattern.

Somatic gene copy number alterations in colorectal cancer: new quest for cancer drivers and biomarkers

Colorectal cancer (CRC) results from the accumulation of genetic alterations, and somatic copy number alterations (CNAs) are crucial for the development of CRC. Genome-wide survey of CNAs provides opportunities for identifying cancer driver genes in an unbiased manner. The detection of aberrant CNAs may provide novel markers for the early diagnosis and personalized treatment of CRC. A major challenge in array-based profiling of CNAs is to distinguish the alterations that play causative roles from the random alterations that accumulate during colorectal carcinogenesis. In this view, we systematically discuss the frequent CNAs in CRC, focusing on functional genes that have potential diagnostic, prognostic and therapeutic significance.

Mitochondrial microsatellite instability in patients with metastatic colorectal cancer

Mitochondrial microsatellite instability (mtMSI), a change in length in mtDNA microsatellite sequences between normal and tumor tissue, has been described as a frequent occurrence in colorectal cancer (CRC). We evaluated the prevalence and prognostic value of mtMSI and its relation to nuclear microsatellite instability (MSI) in patients with metastatic CRC (mCRC). At six loci (D310, D514, D16184, ND1, ND5, and COX1), the mitochondrial DNA sequence was analyzed in normal and tumor tissue, and the mtMSI status was determined. We evaluated the prevalence and outcome in terms of overall survival (OS) in 83 CRC patients with a MSI tumor (including 39 patients with Lynch syndrome) and in 99 mCRC patients with a microsatellite stable (MSS) tumor. A meta-analysis was performed to compare our findings with existing data. mtMSI at the D-loop region was found in 54.4 % (99 out of 182) of all patients. Prevalence of mtMSI was most pronounced at the D310 locus (50.5 %). Prevalence of mtMSI at the D-loop region was not different among patients with MSI compared to MSS tumors. There was no effect of mtMSI on prognosis in patients with MSI or MSS tumors. Prevalence of mtMSI was high in mCRC patients with both MSI and MSS tumors, but there was no correlation with prognosis. mtMSI was particularly present at the D310 locus.

Mitochondrial DNA aberrations and pathophysiological implications in hematopoietic diseases, chronic inflammatory diseases, and cancers

Mitochondria are important intracellular organelles that produce energy for cellular development, differentiation, and growth. Mitochondrial DNA (mtDNA) presents a 10- to 20-fold higher susceptibility to genetic mutations owing to the lack of introns and histone proteins. The mtDNA repair system is relatively inefficient, rendering it vulnerable to reactive oxygen species (ROS) produced during ATP synthesis within the mitochondria, which can then target the mtDNA. Under conditions of chronic inflammation and excess stress, increased ROS production can overwhelm the antioxidant system, resulting in mtDNA damage. This paper reviews recent literature describing the pathophysiological implications of oxidative stress, mitochondrial dysfunction, and mitochondrial genome aberrations in aging hematopoietic stem cells, bone marrow failure syndromes, hematological malignancies, solid organ cancers, chronic inflammatory diseases, and other diseases caused by exposure to environmental hazards.

Cellular comparison of sinus mucosa vs polyp tissue from a single sinus cavity in chronic rhinosinusitis

BACKGROUND

Nasal polyposis is a common development in chronic rhinosinusitis (CRS), and sinus mucosa and polyp tissue have been used interchangeably in studies investigating CRS. However, potential differences may exist between these 2 tissue types, which have not been entirely characterized.

METHODS

A cross-sectional study of CRS with nasal polyposis (CRSwNP) patients undergoing endoscopic sinus surgery was conducted. Sinus mucosal biopsies and corresponding polyp tissue were obtained from the same sinus cavity via flow cytometry, single-cell suspensions identified type 2 innate lymphoid cells (ILC2s), CD4 and CD8 T cells, activated CD4 and CD8 T cells, plasma cells, plasmacytoid dendritic cells (pDCs), regulatory T cells, T follicular helper cells, B cells, and immunoglobulin A (IgA)(+) and IgG(+) B cells. Cells were measured as a percentage of CD45(+) cells. Paired nonparametric comparisons between sinus and polyp tissue were performed.

RESULTS

Ten patients (50% female; age 48 ± 16 years) were recruited. Significantly elevated ILC2 levels were found in polyp tissue compared to sinus mucosa (0.12 [0.07 to 0.23] vs 0.07 [0.04 to 0.16], p = 0.02), as well as plasma cells (2.25 [0.84 to 3.68] vs 1.18 [0.74 to 2.41], p = 0.01); pDCs (0.15 [0.12 to 0.50[ vs 0.04 [0.02 to 0.17], p = 0.03); activated CD8 T cells (29.22 [17.60 to 41.43] vs 16.32 [10.07 to 36.16], p = 0.04) and IgG(+) B cells (6.96 [0.06 to 11.82] vs 1.51 [0.38 to 5.13], p = 0.04). Other cell populations showed no significant differences.

CONCLUSION

Polyps have a similar cellular composition to that of mucosa. Higher levels of ILC2s, plasma cells, pDCs, activated CD8 T cells, and IgG(+) B cells in polyp tissue may be reflective of cell populations driving nasal polyp development. The cellular machinery of CRS is present in polyps and representative of the disease process. This pilot study strongly suggests that a larger study would provide significant insights into the relationship of sinus mucosa to pathogenesis of nasal polyps.

Decreased copy number of mitochondrial DNA: A potential diagnostic criterion for gastric cancer

An alteration in the mitochondrial DNA (mtDNA) copy number has been detected in numerous human cancers. However, certain changes in the mtDNA copy number that occur during the initiation and progression of gastric cancer remain undetected. In the present study, using quantitative PCR analysis, the quantitative changes in mtDNA were observed during the initiation and progression of gastric cancer. Furthermore, the possible correlation between the changes in mtDNA and the clinicopathological stage were also investigated. However, the mechanism by which the change in mtDNA copy number occurs remains to be elucidated. Epigenetic changes are believed to play a significant role in regulating the mtDNA content. In order to determine whether there is a potential correlation between DNA methylation and mtDNA regulation, in vitro demethylation experiments were performed. Tumor tissues and corresponding non-cancerous tissues were surgically resected from 76 gastric cancer patients between 2010 and 2011. The results revealed that the average relative mtDNA copy numbers were 94.71±28.11 in the cancer tissues and 111.68±21.84 in the corresponding non-cancerous tissues (P<0.01). The quantitative changes in mtDNA demonstrated a significant decrease in gastric cancer, particularly in ill-defined stage III and IV cases, but had no association with gender. The mtDNA copy numbers demonstrated a marked increase (P<0.05) following demethylation treatment. The present results indicate that the mtDNA copy number plays a significant role during the progression of colorectal cancer, particularly during the late clinicopathological stages, and that the change in the mtDNA copy number may correlate with DNA methylation.

Is mitochondrial DNA content a potential biomarker of mitochondrial dysfunction?

Mitochondrial dysfunction is central to numerous diseases of oxidative stress. Changes in mitochondrial DNA (MtDNA) content, often measured as mitochondrial genome to nuclear genome ratio (Mt/N) using real time quantitative PCR, have been reported in a broad range of human diseases, such as diabetes and its complications, obesity, cancer, HIV complications, and ageing. We propose the hypothesis that MtDNA content in body fluids and tissues could be a biomarker of mitochondrial dysfunction and review the evidence supporting this theory. Increased reactive oxygen species resulting from an external trigger such as hyperglycaemia or increased fat in conditions of oxidative stress could lead to enhanced mitochondrial biogenesis, and increased Mt/N. Altered MtDNA levels may contribute to enhanced oxidative stress and inflammation and could play a pathogenic role in mitochondrial dysfunction and disease. Changes in Mt/N are detectable in circulating cells such as peripheral blood mononuclear cells and these could be used as surrogate to predict global changes in tissues and organs. We review a large number of studies reporting changes in MtDNA levels in body fluids such as circulating blood cells, cell free serum, saliva, sperm, and cerebrospinal fluid as well as in tumour and normal tissue samples. However, the data are often conflicting as the current methodology used to measure Mt/N can give false results because of one or more of the following reasons (1) use of mitochondrial primers which co-amplify nuclear pseudogenes (2) use of nuclear genes which are variable and/or duplicated in numerous locations (3) a dilution bias caused by the differing genome sizes of the mitochondrial and nuclear genome and (4) template preparation protocols which affect the yields of nuclear and mitochondrial genomes. Development of robust and reproducible methodology is needed to test the hypothesis that MtDNA content in body fluids is biomarker of mitochondrial dysfunction.

Frequent occurrence of mitochondrial DNA mutations in Barrett's metaplasia without the presence of dysplasia

Background

Barrett's esophagus (BE) is one of the most common premalignant lesions and can progress to esophageal adenocarcinoma (EA). The numerous molecular events may play a role in the neoplastic transformation of Barrett’s mucosa such as the change of DNA ploidy, p53 mutation and alteration of adhesion molecules. However, the molecular mechanism of the progression of BE to EA remains unclear and most studies of mitochondrial DNA (mtDNA) mutations in BE have performed on BE with the presence of dysplasia.

Methods/Findings

Thus, the current study is to investigate new molecular events (Barrett’s esophageal tissue-specific-mtDNA alterations/instabilities) in mitochondrial genome and causative factors for their alterations using the corresponding adjacent normal mucosal tissue (NT) and tissue (BT) from 34 patients having Barrett’s metaplasia without the presence of dysplasia. Eighteen patients (53%) exhibited mtDNA mutations which were not found in adjacent NT. mtDNA copy number was about 3 times higher in BT than in adjacent NT. The activity of the mitochondrial respiratory chain enzyme complexes in tissues from Barrett’s metaplasia without the presence of dysplasia was impaired. Reactive oxygen species (ROS) level in BT was significantly higher than those in corresponding samples.

Conclusion/Significance

High ROS level in BT may contribute to the development of mtDNA mutations, which may play a crucial role in disease progression and tumorigenesis in BE.

Sinonasal seromucinous hamartoma: a review of the literature and a case report with focal myoepithelial cells

Seromucinous hamartoma is a benign lesion of the sinonasal tract. Since its description in 1974, only a small number of additional cases have been reported. It is composed of a proliferation of seromucinous glands and ducts within a variable fibrous stroma. The serous component typically stains positively for S100 (at least focally) and lacks p63 positive abluminal cells. The lack of myoepithelial/basal cells is an important diagnostic feature of seromucinous hamartoma; their absence could lead to an incorrect diagnosis of low-grade sinonasal adenocarcinoma. We report the case of a polypoid mass resected from the posterior nasal cavity and nasopharynx of a 54-year-old woman. The lesion contained a population of small and large glands lined by cuboidal to flattened cells within a hypocellular stroma varying from dense and sclerotic to myxoid. Additionally, there was a superficial focus of ciliated invaginated surface epithelium and glands. Throughout the lesion there were no cytologic or architectural features of malignancy. The histologic features were diagnostic of seromucinous hamartoma. Immunohistochemistry showed focal S100 positivity of the serous glands. However, in contrast to previously reported cases, the glands focally showed an outer basal layer that was calponin, p63 and actin positive. Our case demonstrates two important points. First, complete absence of p63 staining should not necessarily be a required feature in the diagnosis of seromucinous hamartoma. Second, the ciliated larger glands--in keeping with respiratory epithelial adenomatoid hamartoma (REAH)--support the suggestion that seromucinous hamartoma and REAH are a spectrum of lesions, often seen together.

High-frequency minisatellite instability of the mitochondrial genome in colorectal cancer tissue associated with clinicopathological values

Most studies of mitochondrial DNA (mtDNA) mutations in colorectal cancer have used case-control and case-database comparisons without searching their clinical relevance. This study was to investigate colorectal cancer tissue-specific mtDNA mutations from 54 matched colorectal cancer and adjacent normal tissues and then to evaluate their clinical values. This study focused on analyzing control region including mtDNA minisatellites and coding regions. Cancer tissue-specific mtDNA mutations were found in over half of the patients (59%). The patterns of mtDNA mutations were substitution only (13%), mtDNA minisatellite instability (mtMSI) (20%) and both mutations combined (26%). mtMSI in colorectal cancer was mainly occurred in the 303 polyC (35%) and 16184 poly C (19%) minisatellite. mtDNA copy number and hydrogen peroxide level were significantly increased in colorectal cancer tissue. The amount of mtDNA large deletions was significantly decreased in colorectal cancer tissue compared with those from matched normal mucosa (p = 0.03). The activity of the mitochondrial respiratory chain enzyme complexes I, II and III in colorectal cancer tissues was impaired. mtDNA haplogroup B4 might be closely associated with colorectal cancer risk. The patient group harboring cancer tissue-specific mtDNA mutations showed larger tumor sizes (p = 0.005) and more advanced TNM stages (p = 0.002). Thus, mtDNA mutations in colorectal cancer might be implicated in risk factors that induce poor outcomes and tumorigenesis.

Mitochondrial DNA copy number and hnRNP A2/B1 protein: biomarkers for direct exposure of benzene

The present study was performed to identify biomarkers for exposure of benzene in blood cells and hematopoietic tissues. Peripheral mononuclear cells, hematopoietic stem cells, and leukemia cell lines were cultured in RPMI 1640 media with the addition of 0, 1, and 10 mM of benzene. Hydrogen peroxide was measured using an enzyme immunoassay. Mitochondrial mass, membrane potential, and mitochondrial DNA (mtDNA) copy number were measured using MitoTracker Green/Red probes, and real-time polymerase chain reaction. In addition, two-dimensional gel electrophoresis and mass spectrometry matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) technology were performed to identify protein markers. The mitochondrial contents and membrane potentials were dramatically increased after three weeks of direct benzene exposure. The hydrogen peroxide level increased significantly after two weeks of treatment with benzene (4.4 ± 1.9 µM/mg protein) compared to the non-benzene treatment group (1.2 ± 1.0; p = 0.001). The mtDNA copy number gradually increased after exposure to benzene. Numerous protein markers showed significant aberrant expression after exposure to benzene. Among them, the heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 was markedly decreased after exposure to benzene. Thus, increased mitochondrial mass, mtDNA copy number, and the hnRNP A2/B1 protein were biomarkers for benzene-related toxicity and hematotoxicity.

Mitochondrial DNA as a non-invasive biomarker: accurate quantification using real time quantitative PCR without co-amplification of pseudogenes and dilution bias

Circulating mitochondrial DNA (MtDNA) is a potential non-invasive biomarker of cellular mitochondrial dysfunction, the latter known to be central to a wide range of human diseases. Changes in MtDNA are usually determined by quantification of MtDNA relative to nuclear DNA (Mt/N) using real time quantitative PCR. We propose that the methodology for measuring Mt/N needs to be improved and we have identified that current methods have at least one of the following three problems: (1) As much of the mitochondrial genome is duplicated in the nuclear genome, many commonly used MtDNA primers co-amplify homologous pseudogenes found in the nuclear genome; (2) use of regions from genes such as β-actin and 18S rRNA which are repetitive and/or highly variable for qPCR of the nuclear genome leads to errors; and (3) the size difference of mitochondrial and nuclear genomes cause a "dilution bias" when template DNA is diluted. We describe a PCR-based method using unique regions in the human mitochondrial genome not duplicated in the nuclear genome; unique single copy region in the nuclear genome and template treatment to remove dilution bias, to accurately quantify MtDNA from human samples.

Correlation between increased copy number of mitochondrial DNA and clinicopathological stage in colorectal cancer

Change of mitochondrial DNA (mtDNA) copy numbers is considered to be an important hallmark of cancers. However, whether quantitative changes in mtDNA occur during the initiation and progression of colorectal cancer remains to be determined. Quantitative change in mtDNA was observed during the initiation and progression of colorectal cancer and possible correlations of the mtDNA copy number in colorectal cancer with the clinicopathological stage were investigated. Tumor tissues and the corresponding non-cancerous tissues were surgically resected from 24 colon and 20 rectal patients between 2008 and 2009. β-actin expression was quantified in all of the specimens, and the copy numbers were calculated. In colorectal cancer, the quantitative changes of mtDNA exhibited a significant increase. In 24 cases of colon cancer, the average relative mtDNA copy number ratios were 115.15±31.57 in cancer tissues and 54.09±13.22 in the corresponding non-cancerous tissues (p<0.01). Furthermore, in 20 cases of rectal cancer, the ratios were 145.6±43.83 in cancer tissues and 55.58±12.47 in the corresponding non-cancerous tissues (p<0.001). Following correlation with clinicopathological data, change of the mtDNA copy number in colorectal cancer exhibited a significant association with clinicopathological stage, but no association with gender. Moreover, this increase was particularly marked in stages Ⅰ and Ⅱ. Our results indicate that mtDNA copy number plays a significant role during the initiation and progression of colorectal cancer, particularly during early clinicopathological stages.

Nasal seromucinous hamartoma (microglandular adenosis of the nose): a morphological and molecular study of five cases

Five cases of nasal seromucinous hamartoma were studied and their clinical, morphological, immunohistochemical and molecular data are reported. The patients, three females and two males, ranged in age from 49 to 66 years (mean 56 year, SD ± 7.91). All lesions were located in the nasal cavity. In four cases where follow-up was obtained, no recurrence was evident. In all cases, numerous small seromucinous tubules, embedded in a cellular stroma, were present in the lamina propria. Tubules were lined by one layer of cuboidal cells which displayed luminal phenotype positive for lysozyme and EMA in four, and S100 protein in all cases. Collagen IV and laminin positive basal lamina outlined the tubules which lacked basal cells. Stromal spindle cells present among tubules were immunoreactive for calponin in all cases and for alpha-smooth muscle actin in four cases. DNA mutation analysis of mitochondrial D-loop region was performed by direct sequencing in order to verify the mutation rate of these lesions. The tubules of the five seromucinous hamartomas showed a higher mutation rate especially in heteroplasmy (0.52% homoplasmy, 2.02% heteroplasmy) in comparison to normal seromucinous glands which exhibited a lower mutation frequency (0.83%). This is considered a sign of a low cellular proliferation rate consistent with a benign process. It is concluded that nasal seromucinous hamartomas are benign glandular proliferations that may resemble microglandular adenosis of the breast. Their distinction from benign and malignant mimics is discussed.

Analysis of fluorescence in situ hybridization, mtDNA quantification, and mtDNA sequence for the detection of early bladder cancer

We designed this study to test the sensitivities of cytology, the nuclear matrix protein 22 (NMP22) assay, and fluorescence in situ hybridization (FISH) in the early detection of urothelial carcinoma, and to identify mtDNA alterations in urinary epithelial cells. We collected 41 urine samples and 26 corresponding peripheral blood samples from patients with clinically suspected urothelial carcinoma. The FISH and NMP22 assays detected 92.1% of the cancers, and cytology detected 60.5%. In the low-grade group, NMP22 and FISH analyses were more sensitive than cytology, but in the high-grade group, all three methods showed approximately 90% sensitivity. Overall, the FISH and NMP22, or FISH and cytology assays combined detected 97.4% of cancers, while cytology with NMP22 detected 92.1%. In the low-grade group, the sensitivity of the three methods combined was above 80%, but in high-grade group, the combined sensitivity was approximately 100%. In the mtDNA control region, we detected characteristic heteroplasmic mtDNA substitution mutations in 1 patient and a mtDNA length heteroplasmic mutation in 303 polyC or 16184 poly C in 20 patients. Overall, urothelial carcinoma-specific mtDNA mutations were observed in 20 of the 26 patients (76.9%). The average mtDNA copy numbers in urine samples and corresponding peripheral blood samples (83.45 +/- 60.36 and 39.0 +/- 24.38, respectively) (mean +/- standard deviation [SD]) differed significantly (P < 0.001). The mtDNA copy numbers in the urine samples from patients with high-grade and low-grade tumors (81.83 +/- 67.78 and 86.49 +/- 46.69, respectively) did not differ significantly (P = 0.589). In conclusion, the FISH assay showed the highest sensitivity for detecting low-grade urothelial carcinoma, and mtDNA copy numbers in urine samples were higher than those in the corresponding peripheral blood samples. The frequency of mtDNA mutations in the D-loop region in patients with cancer was approximately 80% in our study. This report further supports the significance of genetic alteration in urothelial carcinoma and the clinical utility of the FISH, mtDNA quantitation polymerase chain reaction, mtDNA sequencing, and capillary electrophoresis for this purpose.