ABSTRACT
BACKGROUND: Valid patient-reported outcome (PRO) measures are required to evaluate alopecia areata (AA) treatments. OBJECTIVES: To develop a content-valid and clinically meaningful PRO measure to assess AA scalp hair loss with scores comparable with the five-response-level Alopecia Areata Investigator Global Assessment (AA-IGA™). METHODS: A draft PRO measure was developed based on input from 10 clinical experts in AA. The PRO measure was cognitively debriefed, modified and finalized through two rounds of qualitative semistructured interviews with patients with AA who had experienced ≥ 50% scalp hair loss. Data were thematically analysed. RESULTS: Adults (round 1: n = 25; round 2: n = 15) and adolescents aged 15-17 years (round 1: n = 5) in North America participated. All patients named scalp hair loss as a key AA sign or symptom. Patients demonstrated the ability to self-report their current amount of scalp hair using percentages. In round 1 not all patients interpreted the measurement concept consistently; therefore, the PRO was modified to clarify the measurement concept to improve usability. Following modifications, patients in round 2 responded without difficulty to the PRO measure. Patients confirmed that they could use the five-level response scale to rate their scalp hair loss: no missing hair, 0%; limited, 1-20%; moderate, 21-49%; large, 50-94%; nearly all or all, 95-100%. Almost all patients deemed hair regrowth resulting in ≤ 20% scalp hair loss a treatment success. CONCLUSIONS: The Scalp Hair Assessment PRO™ is a content-valid, clinically meaningful assessment of distinct gradations of scalp hair loss for evaluating AA treatment for patients with ≥ 50% hair loss at baseline.
Subject(s)
Alopecia Areata , Adolescent , Adult , Alopecia , Alopecia Areata/diagnosis , Hair , Humans , North America , Patient Reported Outcome Measures , ScalpABSTRACT
BACKGROUND: Content-valid and clinically meaningful instruments are required to evaluate outcomes of therapeutic interventions in alopecia areata (AA). OBJECTIVES: To develop an Investigator's Global Assessment (IGA) to interpret treatment response in AA treatment studies. METHODS: Qualitative interviews were conducted in the USA with expert dermatologists and with patients with AA who had experienced ≥ 50% scalp-hair loss. Thematic data analysis identified critical outcomes and evaluated the content validity of the new IGA. RESULTS: Expert clinicians (n = 10) judged AA treatment success by the amount of scalp-hair growth (median 80% scalp hair). Adult (n = 25) and adolescent (n = 5) patients participated. Scalp-hair loss was the most bothersome AA sign/symptom for most patients. Perceived treatment success - short of 100% scalp hair - was the presence of ~ 70-90% scalp hair (median 80%). Using additional clinician and patient insights, the Alopecia Areata Investigator Global Assessment (AA-IGA™) was developed. This clinician-reported outcome assessment is an ordinal, static measure comprising five severity categories of scalp-hair loss. Nearly all clinicians and patients in this study agreed that, for patients with ≥ 50% scalp-hair loss, successful treatment would be hair regrowth resulting in ≤ 20% scalp-hair loss. CONCLUSIONS: We recommend using the Severity of Alopecia Tool to assess the extent (0-100%) of scalp-hair loss. The AA-IGA is a robust ordinal measure providing distinct and clinically meaningful gradations of scalp-hair loss that reflects patients' and expert clinicians' perspectives and treatment expectations. What is already known about this topic? The Severity of Alopecia Tool is widely used to assess the extent of scalp-hair loss in patients with alopecia areata. Guidelines define treatment success as a 50% improvement in scalp hair, and clinical trials have used dynamic thresholds of 50% and 90%. However, there is no clinical consensus on these endpoints, and patient perspectives on treatment success are unknown. What does this study add? Through qualitative interviews with 10 expert dermatologists and 30 patients with alopecia areata who had experienced ≥ 50% scalp-hair loss, we developed the Alopecia Areata Investigator Global Assessment (AA-IGA™) to measure five clinically meaningful gradations of alopecia areata scalp-hair loss that reflects patients' and clinicians' perspectives and expectations of treatment success in alopecia areata treatment studies. What are the clinical implications of this work? The AA-IGA is a robust ordinal measure that can inform clinical evaluation of alopecia areata treatment outcomes. The AA-IGA can be used to determine clinically meaningful treatment success for alopecia areata, with success defined by patients and clinicians as reaching ≤ 20% scalp-hair loss. Linked Comment: Blome. Br J Dermatol 2020; 183:609.
Subject(s)
Alopecia Areata , Adolescent , Adult , Alopecia , Alopecia Areata/drug therapy , Hair , Humans , ScalpSubject(s)
Alopecia Areata/drug therapy , Piperidines/therapeutic use , Protein Kinase Inhibitors/therapeutic use , Pyrazoles/therapeutic use , Pyrimidines/therapeutic use , Pyrroles/therapeutic use , Adult , Female , Humans , Janus Kinases/antagonists & inhibitors , Middle Aged , Nitriles , Recurrence , Withholding TreatmentABSTRACT
OBJECTIVE: To determine whether pulmonary changes on computed tomography (CT) are helpful in differentiating between pleural tuberculosis (TB) and non-tuberculous pleural infection MATERIALS AND METHODS: We retrospectively reviewed CT scans of patients with pleural tuberculous and non-tuberculous empyema, focusing on pulmonary changes such as consolidation, ground glass opacity, interlobular septal thickening, cavitation, abscess and presence and distribution of micronodules. We also assessed the presence of loss of overlying pleural integrity, peripheral bronchopleural fistula and lymphadenopathy. RESULTS: We evaluated 65 patients with pleural TB and 43 with empyema. CT findings of pleural TB differed significantly from those of empyema with interlobular septal thickening (P = 0.022) and micronodules with subpleural, peribronchovascular and septal distribution (P < 0.001). Subpleural abscess was more frequently seen in empyema, accompanying loss of overlying pleural integrity and peripheral bronchopleural fistula (P < 0.001), but there was no statistical difference between the two groups in prevalence of consolidation, ground glass opacity, cavitation, centrilobular nodules or lymphadenopathy. CONCLUSION: Interlobular septal thickening and micronodules with perilymphatic distribution are characteristic CT findings of pleural TB but not empyema. Presence of subpleural abscess and loss of pleural integrity or peripheral bronchopleural fistula are highly suggestive of empyema.
Subject(s)
Empyema, Pleural/diagnostic imaging , Empyema, Pleural/physiopathology , Tomography, X-Ray Computed , Tuberculosis, Pleural/diagnostic imaging , Tuberculosis, Pleural/physiopathology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Lung/diagnostic imaging , Male , Middle Aged , Republic of Korea , Retrospective Studies , Young AdultABSTRACT
Nasopharyngeal carcinoma (NPC) is a cancer that occurs in high frequency in Southern China. A previous functional complementation approach and the subsequent cDNA microarray analysis have identified that serum amyloid A1 (SAA1) is an NPC candidate tumor suppressor gene. SAA1 belongs to a family of acute-phase proteins that are encoded by five polymorphic coding alleles. The SAA1 genotyping results showed that only three SAA1 isoforms (SAA1.1, 1.3 and 1.5) were observed in both Hong Kong NPC patients and healthy individuals. This study aims to determine the functional role of SAA1 polymorphisms in tumor progression and to investigate the relationship between SAA1 polymorphisms and NPC risk. Indeed, we have shown that restoration of SAA1.1 and 1.3 in the SAA1-deficient NPC cell lines could suppress tumor formation and angiogenesis in vitro and in vivo. The secreted SAA1.1 and SAA1.3 proteins can block cell adhesion and induce apoptosis in the vascular endothelial cells. In contrast, the SAA1.5 cannot induce apoptosis or inhibit angiogenesis because of its weaker binding affinity to αVß3 integrin. This can explain why SAA1.5 has no tumor-suppressive effects. Furthermore, the NPC tumors with this particular SAA1.5/1.5 genotype showed higher levels of SAA1 gene expression, and SAA1.1 and 1.3 alleles were preferentially inactivated in tumor tissues that were examined. These findings further strengthen the conclusion for the defective function of SAA1.5 in suppression of tumor formation and angiogenesis. Interestingly, the frequency of the SAA1.5/1.5 genotype in NPC patients was ~2-fold higher than in the healthy individuals (P=0.00128, odds ratio=2.28), which indicates that this SAA1 genotype is significantly associated with a higher NPC risk. Collectively, this homozygous SAA1.5/1.5 genotype appears to be a recessive susceptibility gene, which has lost the antiangiogenic function, whereas SAA1.1 and SAA1.3 are the dominant alleles of the tumor suppressor phenotype.
Subject(s)
Gene Expression Regulation, Neoplastic , Genetic Predisposition to Disease , Nasopharyngeal Neoplasms , Neovascularization, Pathologic , Polymorphism, Genetic , Serum Amyloid A Protein , Tumor Suppressor Proteins , Alleles , Apoptosis , Carcinoma , Cell Adhesion , Cell Line, Tumor , Coculture Techniques , Endothelial Cells , Humans , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/genetics , Nasopharyngeal Neoplasms/metabolism , Nasopharyngeal Neoplasms/pathology , Neovascularization, Pathologic/genetics , Neovascularization, Pathologic/metabolism , Neovascularization, Pathologic/pathology , Serum Amyloid A Protein/biosynthesis , Serum Amyloid A Protein/genetics , Tumor Suppressor Proteins/biosynthesis , Tumor Suppressor Proteins/geneticsABSTRACT
Arthrogryposis, renal dysfunction, and cholestasis (ARC) syndrome is an autosomal recessive disorder caused by mutations in the VPS33B and VIPAS39. Here, we report novel mutations identified in four patients with ARC syndrome. We analyzed the entire coding regions of the VPS33B and VIPAS39 genes by direct sequencing. To detect novel splice site mutations, mRNA transcripts were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and sequencing. All four patients had compound heterozygous variants in the VPS33B gene. One patient had a previously reported splice site variant with unknown significance, c.239+5G>A, and a novel nonsense mutation, c.621G>A. The other three patients had the c.403+2T>A mutation, and each of them carried one of the splice site variants, c.239+5G>A or c.499-11G>A. c.239+5G>A and c.499-11G>A created novel splice sites which resulted in abnormal transcripts. No significant VIPAS39 mutation was detected in all patients. In patients suspected with ARC syndrome, mutation analysis of the VPS33B gene should be employed as a primary diagnostic test before performing invasive testing procedures such as organ biopsies. Performing mRNA analysis can be useful in predicting the pathogenic phenotype when the mutation seems to affect a normal splicing mechanism.
Subject(s)
Arthrogryposis/genetics , Cholestasis/genetics , Mutation , RNA Splice Sites/genetics , Renal Insufficiency/genetics , Vesicular Transport Proteins/genetics , Arthrogryposis/diagnosis , Cholestasis/diagnosis , DNA Mutational Analysis , Female , Heterozygote , Humans , Infant , Infant, Newborn , Male , Phenotype , Renal Insufficiency/diagnosis , Republic of KoreaABSTRACT
Zinc-finger, MYND-type containing 10 (ZMYND10), or more commonly called BLU, expression is frequently downregulated in nasopharyngeal carcinoma (NPC) and many other tumors due to promoter hypermethylation. Functional evidence shows that the BLU gene inhibits tumor growth in animal assays, but the detailed molecular mechanism responsible for this is still not well understood. In current studies, we find that 93.5% of early-stage primary NPC tumors show downregulated BLU expression. Using a PCR array, overexpression of the BLU gene was correlated to the angiogenesis network in NPC cells. Moreover, expression changes of the MMP family, VEGF and TSP1, were often detected in different stages of NPC, suggesting the possibility that BLU may be directly involved in the microenvironment and anti-angiogenic activity in NPC development. Compared with vector-alone control cells, BLU stable transfectants, derived from poorly-differentiated NPC HONE1 cells, suppress VEGF165, VEGF189 and TSP1 expression at both the RNA and protein levels, and significantly reduce the secreted VEGF protein in these cells, reflecting an unknown regulatory mechanism mediated by the BLU gene in NPC. Cells expressing BLU inhibited cellular invasion, migration and tube formation. These in vitro results were further confirmed by in vivo tumor suppression and a matrigel plug angiogenesis assay in nude mice. Tube-forming ability was clearly inhibited, when the BLU gene is expressed in these cells. Up to 70-90% of injected tumor cells expressing increased exogenous BLU underwent cell death in animal assays. Overexpressed BLU only inhibited VEGF165 expression in differentiated squamous NPC HK1 cells, but also showed an anti-angiogenic effect in the animal assay, revealing a complicated mechanism regulating angiogenesis and the microenvironment in different NPC cell lines. Results of these studies indicate that alteration of BLU gene expression influences anti-angiogenesis pathways and is important for the development of NPC.
Subject(s)
Chromosomes, Human, Pair 3/genetics , Nasopharyngeal Neoplasms/genetics , Neovascularization, Pathologic/genetics , Signal Transduction/genetics , Tumor Suppressor Proteins/genetics , Animals , Blotting, Western , Carcinoma , Cell Line, Tumor , Cell Movement/genetics , Cells, Cultured , Chromosome Mapping , Cytoskeletal Proteins , Down-Regulation , Female , Gene Expression Regulation, Neoplastic , Humans , Immunohistochemistry , Male , Matrix Metalloproteinases/genetics , Matrix Metalloproteinases/metabolism , Mice, Nude , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/metabolism , Nasopharyngeal Neoplasms/pathology , Reverse Transcriptase Polymerase Chain Reaction , Thrombospondin 1/genetics , Thrombospondin 1/metabolism , Transplantation, Heterologous , Tumor Microenvironment/genetics , Tumor Suppressor Proteins/metabolism , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolismABSTRACT
Steroid 21-hydroxylase deficiency is caused by inactivating mutations in the CYP21A2 gene. This paper reports on the mutation spectrum and the genotype-phenotype correlation of 21-hydroxylase deficiency. 72 unrelated patients with congenital adrenal hyperplasia (CAH) were included. Molecular analysis of CYP21A2 was performed, via the multiplex ligation-dependent probe amplification (MLPA) analysis and sequence-specific differenzial PCR amplification of the CYP21A2 and CYP21A1P genes, using 4 pair-wise sequence-specific primers, followed by sequencing of the entire CYP21A2 gene. Large gene deletions were identified in 45 (31.3%) of the 144 unrelated CAH alleles, whereas the most frequent point mutations were intron 2 splice mutations (c.293-13A>G) (41/144, 28.5%). The MLPA analysis successfully identified 23 of 72 patients (31.9%) with single copy deletion in CYP21A2. This paper describes a rapid and accurate method for the molecular diagnosis of 21-hydroxylase deficiency, which relies on the identification of point mutations and structural rearrangements within the CYP21A2 gene.
Subject(s)
Adrenal Hyperplasia, Congenital/genetics , Gene Deletion , Point Mutation , Steroid 21-Hydroxylase/genetics , Adrenal Hyperplasia, Congenital/diagnosis , Alleles , DNA Mutational Analysis/methods , Female , Humans , Infant, Newborn , Ligase Chain Reaction/methods , Male , Phenotype , Polymerase Chain Reaction/methodsABSTRACT
BACKGROUND: Oesophageal squamous cell carcinoma (SCC) causes the highest number of cancer deaths in some regions of Northern China. Previously, we narrowed down a critical region at 9q33-34, identified to be associated with tumour-suppressive function of deleted in oesophageal cancer 1 (DEC1) in oesophageal SCC. METHODS: We generated DEC1 antibody and constructed tissue microarrays (TMAs) utilising tissue specimens from Henan, a high-risk region for oesophageal SCC, to investigate the importance of DEC1 expression in this cancer. RESULTS: Tissue microarray immunohistochemical staining reveals significant loss of DEC1 from hyperplasia, to tumour, and to lymph node metastasis. In addition, the loss of DEC1 in tumour is age-dependent. Interestingly, there is significant abrogation of DEC1 expression in patients with a family history of oesophageal SCC. Deleted in oesophageal cancer 1 localises to both the cytoplasm and nucleus. The vesicular pattern of DEC1 in the cytoplasm appears to localise at the Golgi and Golgi-endoplasmic reticulum intermediate compartment. CONCLUSION: This is the first TMA study to suggest a clinical association of DEC1 in lymph node metastatic oesophageal SCC, early onset oesophageal SCC and familial oesophageal SCC development. Subcellular localisation of DEC1 and its expression in oesophageal SCC tissues provide important insight for further deciphering the molecular mechanism of DEC1 in oesophageal SCC development.
Subject(s)
Carcinoma, Squamous Cell/metabolism , Esophageal Neoplasms/metabolism , Family Health , Lymphatic Metastasis , Tumor Suppressor Proteins/metabolism , Adult , Aged , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/pathology , Cell Line, Tumor , Cytoplasm/metabolism , Disease Progression , Esophageal Neoplasms/genetics , Esophageal Neoplasms/pathology , Female , Humans , Immunohistochemistry , Male , Middle Aged , Tissue Array AnalysisABSTRACT
Our current understanding of the relationship between psoriasis and psoriatic arthritis remains incomplete, though the evidence from the clinical setting, response to therapeutics, epidemiology, genetics, imaging, and immunopathologic models suggest that they make likely share a common pathogenesis. Psoriatic disease can no longer be thought of as a condition limited to skin and joints. Rather, it must be considered a multi-faceted disorder in which systemic inflammation plays a central role. There is now convincing evidence that individuals with psoriasis have a higher prevalence of co-morbid disease, particularly cardiovascular risk factors, metabolic disorders, and other immune-mediated inflammatory diseases. The cutaneous manifestations of psoriasis place dermatologists in a crucial and privileged role--one that affords us the potential for early detection of associated co-morbid conditions through screening and perhaps impact disease course and clinical outcomes.
Subject(s)
Psoriasis/etiology , Arthritis, Psoriatic/complications , Arthritis, Psoriatic/diagnosis , Arthritis, Psoriatic/epidemiology , Arthritis, Psoriatic/etiology , Arthritis, Psoriatic/immunology , Arthritis, Psoriatic/therapy , Humans , Psoriasis/complications , Psoriasis/diagnosis , Psoriasis/epidemiology , Psoriasis/immunology , Psoriasis/therapyABSTRACT
A gene critical to esophageal cancer has been identified. Functional studies using microcell-mediated chromosome transfer of intact and truncated donor chromosomes 3 into an esophageal cancer cell line and nude mouse tumorigenicity assays were used to identify a 1.61 Mb tumor suppressive critical region (CR) mapping to chromosome 3p14.2. This CR is bounded by D3S1600 and D3S1285 microsatellite markers. One candidate tumor suppressor gene, ADAMTS9, maps to this CR. Further studies showed normal expression levels of this gene in tumor-suppressed microcell hybrids, levels that were much higher than observed in the recipient cells. Complete loss or downregulation of ADAMTS9 gene expression was found in 15 out of 16 esophageal carcinoma cell lines. Promoter hypermethylation was detected in the cell lines that do not express this gene. Re-expression of ADAMTS9 was observed after demethylation drug treatment, confirming that hypermethylation is involved in gene downregulation. Downregulation of ADAMTS9 was also found in 43.5 and 47.6% of primary esophageal tumor tissues from Hong Kong and from the high-risk region of Henan, respectively. Thus, this study identifies and provides functional evidence for a CR associated with tumor suppression on 3p14.2 and provides the first evidence that ADAMTS9, mapping to this region, may contribute to esophageal cancer development.
Subject(s)
ADAM Proteins/genetics , Carcinoma, Squamous Cell/genetics , Chromosomes, Human, Pair 3 , Esophageal Neoplasms/genetics , Genes, Tumor Suppressor , ADAMTS9 Protein , Base Sequence , Chromosome Mapping , DNA , DNA Methylation , Gene Expression Regulation, Neoplastic , Humans , In Situ Hybridization, Fluorescence , Molecular Sequence DataABSTRACT
BACKGROUND: Loss of TP53 function through gene mutation is a critical event in the development and progression of many tumour types including colorectal cancer (CRC). In vitro studies have found considerable heterogeneity amongst different TP53 mutants in terms of their transactivating abilities. The aim of this work was to evaluate whether TP53 mutations classified as functionally inactive (< or=20% of wildtype transactivation ability) had different prognostic and predictive values in CRC compared with mutations that retained significant activity. MATERIALS AND METHODS: TP53 mutations within a large, international database of CRC (n = 3583) were classified according to functional status for transactivation. RESULTS: Inactive TP53 mutations were found in 29% of all CRCs and were more frequent in rectal (32%) than proximal colon (22%) tumours (P < 0.001). Higher frequencies of inactive TP53 mutations were also seen in advanced stage tumours (P = 0.0003) and in tumours with the poor prognostic features of vascular (P = 0.006) and lymphatic invasion (P = 0.002). Inactive TP53 mutations were associated with significantly worse outcome only in patients with Dukes' stage D tumours (RR = 1.71, 95%CI 1.25-2.33, P < 0.001). Patients with Dukes' C stage tumours appeared to gain a survival benefit from 5-fluorouracil-based chemotherapy regardless of TP53 functional status for transactivation ability. CONCLUSIONS: Mutations that inactivate the transactivational ability of TP53 are more frequent in advanced CRC and are associated with worse prognosis in this stage of disease.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/genetics , Mutation , Tumor Suppressor Protein p53/genetics , Adenocarcinoma/drug therapy , Adenocarcinoma/genetics , Adenocarcinoma/pathology , Aged , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/pathology , DNA Mutational Analysis , Exons , Female , Follow-Up Studies , Humans , International Agencies , Male , Middle Aged , Neoplasm Invasiveness/genetics , Neoplasm Invasiveness/pathology , Neoplasm Staging , Survival RateABSTRACT
This paper presents a nonlinear dynamic model for simulation and analysis of a kind of parametrically excited vibration of stay cable caused by support motion in cable-stayed bridges. The sag, inclination angle of the stay cable are considered in the model, based on which, the oscillation mechanism and dynamic response characteristics of this kind of vibration are analyzed through numerical calculation. It is noted that parametrically excited oscillation of a stay cable with certain sag, inclination angle and initial static tension force may occur in cable-stayed bridges due to deck vibration under the condition that the natural frequency of a cable approaches to about half of the first model frequency of the bridge deck system. A new vibration control system installed on the cable anchorage is proposed as a possible damping system to suppress the cable parametric oscillation. The numerical calculation results showed that with the use of this damping system, the cable oscillation due to the vibration of the deck and/or towers will be considerably reduced.
ABSTRACT
The 1BL.1RS translocations between wheat ( Triticum aestivum L.) and rye ( Secale cereale L.) are widely used in bread wheat breeding programs, but all modern wheat cultivars with the 1BL.1RS have shown genetic vulnerability due to one rye source - a German cultivar, Petkus. We have developed, a new 1BL.1RS wheat-rye translocation line from the backcross of the F(1) hybrid of wheat cv. Olmil and rye cv. Paldanghomil, both cultivars from Korea. The GISH technique was applied to identify the presence of rye chromatin in 467 BC(1)F(6) lines selected from 77 BC(1)F(5) lines. Only one line, Yw62-11, showed wheat-rye translocated chromosomes, with a somatic chromosome number of 2n=42. C-banding patterns revealed that the translocated chromosome was 1BL.1RS, showing prominent bands in the terminal and sub-terminal regions of the short arm as well as in the centromeric region and terminal region of the long arm. This new 1BL.1RS translocation line formed 21 bivalents like common wheat at meiotic metaphase I, thereby showing complete homology.
ABSTRACT
Analysis of the loss of heterozygosity (LOH) detected by polymerase chain reaction techniques using 18 polymorphic markers localized to chromosomes 3p, 5, 17, and 18q in 40 Hong Kong Chinese esophageal squamous cell carcinoma (ESC) patients showed that multiple alterations on several chromosomes are involved in ESC development. The LOH rates detected for markers on chromosome 3 ranged from 44.0 to 85.7%, for chromosome 5 from 40.9 to 61.9%, for chromosome 17 from 40.0 to 100%, and for chromosome 18 from 38.9 to 58.3%. No significant association was observed between LOH and the clinical and histopathological parameters.
Subject(s)
Carcinoma, Squamous Cell/genetics , Chromosomes , Esophageal Neoplasms/genetics , Loss of Heterozygosity , Aged , Asian People , China , Chromosome Mapping , Female , Humans , Male , Middle Aged , Polymerase Chain ReactionABSTRACT
Our aim was to reveal the significance of tumor-suppressor genes and genomic instability in 99 Hong Kong Chinese colorectal carcinoma (CRC) patients by PCR-LOH analysis and PCR-PTT assay. The frequencies of allelic loss of Apc, Mcc and Dcc and of APC truncation were 31.3% (15/48), 11.6% (5/43), 44.4% (20/45) and 46/93 (49.5%), respectively. The frequency of Apc LOH was similar to, the Mcc LOH was lower than, and the Dcc LOH was higher than that reported for Caucasians and Japanese. In Hong Kong CRC patients, the replication error-positive (RER(+)) phenotype occurred with a frequency of 10% (10/99), which was similar to other results using microsatellite markers where RER(+) frequencies ranged from 11% to 28%. The rates of genetic alteration in RER(+) tumors were lower in tumors harboring p53, Mcc and Dcc alterations; similar in Apc; and higher in Ki-ras tumors compared with RER(-) tumors, though these differences did not achieve statistical significance. None of the biomarkers examined were predictive of survival independently, but strong trends confirming earlier observations of associations between RER(+) phenotypes with proximal tumor location and poorly differentiated tumor status were noted. The RER(+) phenotype was correlated significantly to the less aggressive Duke's stage B and improved prognosis. Additionally, tumors with RER(+) phenotypes were positively correlated with young age and sex. Our results support the observation that a subset of younger male CRC patients in Hong Kong may develop CRC via the RER pathway and show differences in RER status and sex. A significantly higher percentage of older Hong Kong Chinese CRC patients had APC truncations. Int. J. Cancer (Pred. Oncol.) 84:404-409, 1999.
Subject(s)
Adenocarcinoma/genetics , Colorectal Neoplasms/genetics , Genes, APC , Genes, DCC , Genes, MCC , Loss of Heterozygosity , Mutation , Adenocarcinoma/drug therapy , Adenocarcinoma/mortality , Adenocarcinoma/pathology , Adenocarcinoma/surgery , Adult , Aged , Aged, 80 and over , Asian People/genetics , Chemotherapy, Adjuvant , China/ethnology , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/mortality , Colorectal Neoplasms/pathology , Colorectal Neoplasms/surgery , DNA Replication , Disease-Free Survival , Female , Genes, ras , Hong Kong , Humans , Male , Middle Aged , Neoplasm Staging , Polymerase Chain Reaction/methods , Sequence Deletion , Survival RateABSTRACT
L-myc genotypes have been correlated with prognosis in different human tumors. Its role in colorectal carcinoma (CRC) is still unclear. This study aimed to assess the L-myc genotypes in 99 Hong Kong Chinese CRC patients by PCR-RFLP techniques. The results obtained were correlated with clinical, histological and pathological parameters and genetic alterations. The observed frequency of L-myc genotypes (LL:LS:SS) was 27:46:26. The ratio of S to L alleles was 0.51:0.49. Distribution of L-myc genotypes and alleles in Hong Kong Chinese CRC was similar to that of healthy Chinese and CRC patients of other ethnic origins. The homozygous SS genotype was significantly associated with Dukes' stages C versus B. Other parameters including sex, differentiation status and survival, and genetic alterations such as p53 and Ki-ras mutations and Dcc LOH had no significant association with L-myc SS genotype.
Subject(s)
Asian People/genetics , Colonic Neoplasms/genetics , Colorectal Neoplasms/genetics , Genes, myc , Polymorphism, Restriction Fragment Length , Proto-Oncogene Proteins c-myc/genetics , Rectal Neoplasms/genetics , China/ethnology , Colonic Neoplasms/mortality , Colonic Neoplasms/pathology , Colorectal Neoplasms/mortality , Colorectal Neoplasms/pathology , DNA, Neoplasm/genetics , Ethnicity/genetics , Female , Genes, ras , Genotype , Hong Kong , Humans , Japan/ethnology , Loss of Heterozygosity , Male , Neoplasm Staging , Polymerase Chain Reaction , Rectal Neoplasms/mortality , Rectal Neoplasms/pathology , Sigmoid Neoplasms/genetics , Sigmoid Neoplasms/mortality , Sigmoid Neoplasms/pathology , Survival Analysis , White People/geneticsABSTRACT
This study investigated the frequency and importance of Ki-ras codon 12 mutations in 99 Hong Kong Chinese colorectal carcinoma specimens by allele-specific oligonucleotide hybridization. The frequency of mutations detected was 30% and the most common mutation observed resulted in aspartic acid substitutions. Previous studies showed that specific Ki-ras mutations have been significantly associated with prognosis. Ki-ras codon 12 point mutational activation in CRC was significantly associated with the differentiation status of tumors in this study. Ethnic differences in the patterns of Ki-ras codon 12 point mutations were observed.