Association between ultrasound BI-RADS signs and molecular typing of invasive breast cancer.

Objective: To explore the correlation between ultrasound images and molecular typing of invasive breast cancer, so as to analyze the predictive value of preoperative ultrasound for invasive breast cancer. Methods: 302 invasive breast cancer patients were enrolled in Heping Hospital affiliated to Changzhi Medical College in Shanxi, China during 2020 to 2022. All patients accepted ultrasonic and pathological examination, and all pathological tissues received molecular typing with immunohistochemical (IHC) staining. The relevance between different molecular typings and ultrasonic image, pathology were evaluated. Results: Univariate analysis: among the four molecular typings, there were significant differences in tumor size, shape, margin, lymph node and histological grade (P<0.05). 1. Size: Luminal A tumor was smaller (69.4%), Basal -like type tumors are mostly larger (60.9%); 2. Shape: Basal-like type is more likely to show regular shape (45.7%); 3. Margin: Luminal A and Luminal B mostly are not circumscribed (79.6%, 74.8%), Basal -like type shows circumscribed(52.2%); 4. Lymph nodes: Luminal A type tends to be normal (87.8%), Luminal B type,Her-2+ type and Basal-like type tend to be abnormal (35.6%,36.4% and 39.1%). There was no significant difference in mass orientation, echo pattern, rear echo and calcification (P>0.05). Multivariate analysis: Basal-like breast cancer mostly showed regular shape, circumscribed margin and abnormal lymph nodes (P<0.05). Conclusion: There are differences in the ultrasound manifestations of different molecular typings of breast cancer, and ultrasound features can be used as a potential imaging index to provide important information for the precise diagnosis and treatment of breast cancer.

Co-Overexpression of Two Key Source Genes, OsBMY4 and OsISA3, Improves Multiple Key Traits of Rice Seeds.

Optimized source-sink interactions are determinants of both rice yield and quality. However, most source genes have not been well studied in rice, a major grain crop. In this study, OsBMY4 and OsISA3, the key ß-amylase and debranching enzymes that control transient starch degradation in rice leaves, were co-overexpressed in rice in order to accelerate starch degradation efficiency and increase the sugar supply for sink organs. Systematic analyses of the transgenic rice indicated that co-overexpression of OsBMY4 and OsISA3 not only promoted rice yield and quality, but also improved seed germination and stress tolerance. Moreover, since the OsBMY4 gene has not been characterized, we generated osbmy4 mutants using CRIPSR/Cas9 gene editing, which helped to reveal the roles of ß-amylase in rice yield and quality. This study demonstrated that specific modulation of the expression of some key source genes improves the source-sink balance and leads to improvements in multiple key traits of rice seeds.

Comparison of the performance of HPV DNA chip test and HPV PCR test in cervical cancer screening in rural China.

Background: This study aimed to evaluate the performance of two different principles of HPV testing in primary cervical cancer screening and ASC-US triage in rural areas. Methods: 3,328 and 3,913 women were enrolled in Shanxi, China in 2017 and 2018, respectively, and screened using liquid-based cytology and different HPV tests with a 4-year follow-up. Different screening methods commonly used in clinical practice were evaluated. Results: In the HPV PCR test cohort, the prevalence of HPV infection was 14.90%. A total of 38 cases of CIN2+ were identified at baseline, 2 of which were in the HPV-negative cohort and the rest in the HPV-positive cohort (2 = 186.85, p < 0.001). Fifty-three cases of CIN2+ were accumulated over 4 years. The HPV infection rate in the HPV DNA chip test cohort was 21.10%. A total of 26 CIN2+ cases were identified at baseline, all in the HPV-positive population (2 = 92.96, p < 0.001). 54 CIN2+ cases were cumulative over 4 years. At 4-year follow-up, HPV-negative results were significantly more protective against cervical intraepithelial neoplasia grade 2 or worse (CIN2+) than normal cytologic results at baseline. HPV screening was more sensitive and specific than cytologic screening (using ASC-US as the threshold) and performed better on the HPV DNA microarray test. In addition, compared with HPV 16/18 testing, sensitivity increases and specificity decreases when using HPV testing for cytologic ASC-US triage, regardless of which HPV test is used. Conclusion: In the rural areas where we implemented the study, HPV tests performed well for screening than LBC and HPV DNA chip testing performed better than HPV PCR testing in the screening cohort. Optimal screening was achieved technically when used in combination with LBC for ASC-US population triage, without thinking the feasibility for resource availability.

Mismatch Repair Deficiency and Microsatellite Instability in Triple-Negative Breast Cancer: A Retrospective Study of 440 Patients.

PURPOSE: To investigate the status of mismatch repair (MMR) and microsatellite instability (MSI) in triple-negative breast cancer (TNBC) and to examine correlations between MMR/MSI status and clinicopathological parameters. METHODS: We retrospectively collected tissue samples from 440 patients with TNBC and constructed tissue microarrays. Protein expression of MLH1, MSH2, MSH6, and PMS2 was detected by immunohistochemistry (IHC). We also analyzed 195 patient samples using MSI polymerase chain reaction (PCR) testing. Correlations between MSI status and clinicopathological parameters and prognosis were analyzed. RESULTS: The median age of the cohort was 49 years (range: 24-90 years) with a median follow-up period of 68 months (range: 1-170 months). All samples were positive for MLH1, MSH2, MSH6, and PMS2, except for one sample identified as MMR-deficient (dMMR) by IHC, with loss of MSH2 and intact MSH6 expression. MSI PCR revealed no case with high-frequency MSI (MSI-H), whereas 14 (7.2%) and 181 (92.8%) samples demonstrated low-frequency and absence of MSI events, respectively. The dMMR sample harbored low-frequency instability, as revealed by MSI PCR, and a possible EPCAM deletion in the tumor, as observed from next-generation sequencing. No correlations were detected between MMR or MSI status and clinicopathological parameters, programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) expression, or survival. CONCLUSIONS: The incidence of dMMR/MSI-H is extremely low in TNBC, and rare discordant MSI PCR/MMR IHC results may be encountered. Moreover, MMR/MSI status may be of limited prognostic value. Further studies are warranted to explore other predictive immunotherapy biomarkers for TNBC.

Systemic mastocytosis with flushing and hypotension: A case report and literature review.

Systemic mastocytosis (SM) is a heterogeneous disease of the bone marrow, which is characterized by the abnormal proliferation and infiltration of mast cells in one or more organs, such as the skin, bone marrow, digestive tract, liver and spleen. Urticaria pigmentosa is a typical but infrequent manifestation of SM. Other clinical presentations are non-specific, varying from pruritus and hypotension to multiple organ dysfunction, which may be lethal when hemodynamic changes occur, such as the sharp decline in blood pressure observed in the present case. In patients who lack skin lesions, the diagnosis of SM is frequently challenging. The present study reported on a 58-year-old male who presented with episodic flushing and syncope. The patient demonstrated marked neutrophilia and reduced blood potassium concentrations soon after the onset of each episode, which was able to last several hours, ranging from once to four times a year. SM without skin lesions was suspected and confirmed after multifocal bone marrow aspiration, which revealed dense infiltrates of mast cells (≥15 mast cells), with positive toluidine blue and CD117 staining. The present case illustrates the significance of taking SM or mast cell activation syndrome into consideration when unexplained recurrent hypotension or even syncope are observed, care should be taken to exclude differential diagnoses, as some of them may have much poorer prognoses and require alternative treatments.

MicroRNA-27b-3p Promotes Tumor Progression and Metastasis by Inhibiting Peroxisome Proliferator-Activated Receptor Gamma in Triple-Negative Breast Cancer.

Introduction: The role and underlying mechanisms of miR-27b-3p in triple-negative breast cancer (TNBC) remains unclear. Methods: miR-27b-3p expression level was evaluated in 99 TNBC patients with a median follow-up time of 133 months. The biological functions of miR-27b-3p by targeting PPARG were assessed by luciferase reporter assay, CCK-8 assay, Transwell assay, wound healing assay, western blot analysis and xenograft models. Results: High level of miR-27b-3p expression was found to confer poor prognosis in TNBC patients. MiR-27b-3p overexpression increased TNBC cell proliferation, migration, invasion, and metastasis. Our data suggested peroxisome proliferator-activated receptor gamma (PPARG) was a target of miR-27b-3p. The capacity of miR-27b-3p to induce TNBC progression and metastasis depended on its inhibition of the PPARG expression. Furthermore, restoring PPARG expression reversed the effect of miR-27b-3p overexpression. Mechanistically, miR-27b-3p regulated metastasis-related pathways through PPARG by promoting epithelial-mesenchymal transition. By suppressing PPARG, miR-27b-3p could also activate transcription factors Snail and NF-κB, thereby promoting metastasis. Conclusions: miR-27b-3p promotes TNBC progression and metastasis by inhibiting PPARG. MiR-27b-3p may be a potential prognostic marker of TNBC, and PPARG may be a potential molecular therapeutic target of TNBC.

Gibberellin recovers seed germination in rice with impaired brassinosteroid signalling.

Seed germination is essential for ensuring grain yield and quality. Germination rate, uniformity, and post-germination growth all contribute to cultivation. Although the phytohormones gibberellin (GA) and brassinosteroid (BR) are known to regulate germination, the underlying mechanism of their crosstalk in co-regulating rice seed germination remains unclear. In this study, the isobaric tags for relative and absolute quantitation (iTRAQ) proteomic approach was employed to identify target proteins responsive to GA during recovery of germination in BR-deficient and BR-insensitive rice. A total of 42 differentially abundant proteins were identified in both BR-deficient and BR-insensitive plants, and most were altered consistently in the two groups. Gene Ontology (GO) analysis revealed enrichment in proteins with binding and catalytic activity. A potential protein-protein interaction network was constructed using STRING analysis, and five Late Embryogenesis Abundant (LEA) family members were markedly down-regulated at both mRNA transcript and protein levels. These LEA genes were specifically expressed in rice seeds, especially during the latter stages of seed development. Mutation of LEA33 affected rice grain size and seed germination, possibly by reducing BR accumulation and enhancing GA biosynthesis. The findings improve our knowledge of the mechanisms by which GA and BR coordinate seed germination.

GS9 acts as a transcriptional activator to regulate rice grain shape and appearance quality.

Identification of grain shape determining genes can facilitate breeding of rice cultivars with optimal grain shape and appearance quality. Here, we identify GS9 (Grain Shape Gene on Chromosome 9) gene by map-based cloning. The gs9 null mutant has slender grains, while overexpression GS9 results in round grains. GS9 encodes a protein without known conserved functional domain. It regulates grain shape by altering cell division. The interaction of GS9 and ovate family proteins OsOFP14 and OsOFP8 is modulated by OsGSK2 kinase, a key regulator of the brassinosteroids signaling pathway. Genetic interaction analysis reveals that GS9 functions independently from other previously identified grain size genes. Introducing the gs9 allele into elite rice cultivars significantly improves grain shape and appearance quality. It suggests potential application of gs9, alone or in combination with other grain size determining genes, in breeding of rice varieties with optimized grain shape.

Intraparenchymal endodermal cyst with spontaneous intracystic hemorrhage in the temporal lobe of an adult.

BACKGROUND: Endodermal cysts (EC) are rare but well-known congenial lesions of the central nervous system mainly located in the spinal subdural space. Intracranial ECs are rare and commonly encountered in the posterior cranial fossa as extra-axial lesions; an intraparenchymal location is exceedingly rare. A complete removal is the best surgical strategy and any residue can cause recurrence. It is necessary to exclude EC in patients with intracranial cystic lesions. We present a case of intraparenchymal EC with spontaneous intracystic hemorrhage in the temporal lobe of an adult. METHODS: A 43-year-old man presented with headache and memory deterioration. Brain computed tomography and magnetic resonance imaging showed a slightly enhanced temporal lobe cystic lesion, which was homogenously hyperintense on T1-and T2-weighted images. There was a suspicion of brain abscess at admission. The lesion was totally removed with a left subtemporal craniotomy. Histological examination revealed an EC with intracystic hemorrhage. RESULTS: The preoperative symptoms were relieved after surgery and 3-month follow-up magnetic resonance imaging found no cystic signs. CONCLUSION: This case suggests that EC should be considered in the differential diagnosis of intracranial cystic lesions and a complete removal is the best strategy of choice.

Template-based Synthesis of a Formate Metal-Organic Framework/Activated Carbon Fiber Composite for High-performance Methane Adsorptive Separation.

Simultaneous improvement in adsorption selectivity and capacity for single adsorbents is challenging but counting for much in adsorptive separations. To this end, a formate metal-organic framework and activated carbon fiber composite was synthesized in our work by a simple two-step process, involving homogeneous precipitation of a MOF precursor on an activated carbon fiber and subsequent template replication. The resultant core-shell composite, ACF@[Ni3 (HCOO)6 ], exhibited optimized adsorption performance both in selectivity and capacity for the separation of CH4 /N2 to most of state-of-the-art adsorbents.

[Automated mapping of urban forests' disturbance and recovery in Nanjing, China].

Using Landsat TM/ETM dense time series observations spanning from 1987 to 2011, taking Laoshan forest farm and Purple Mountain as the research objects, the landsat ecosystem disturbance adaptive processing system (Ledaps) algorithm was used to generate surface reflectance datasets, which were fed to the vegetation change tracker model (VCT) model to derive urban forest disturbance and recovery products over Nanjing, followed by an intensive validation of the products. The results showed that there was a relatively high spatial agreement for forest disturbance products mapped by VCT, ranging from 65.4% to 95.0%. There was an apparent fluctuating forest disturbance and recovery rate over time, and the change trend of forest disturbance occurring at the two sites was roughly similar, but forest recovery was obviously different. Forest coverage in Purple Mountain was less than that in Laoshan forest farm, but the forest disturbance and recovery rates in Laoshan forest farm were larger than those in Purple Mountain.

[Assessing dynamic patterns of forest fragmentation based on a landscape mosaic indicator: a case study of Oregon State, USA].

Effectively assessing landscape pattern characteristics and predicting their dynamics have been a basic prerequisite for more reasonably regulating and managing forest landscape, and maintaining landscape security patterns. In this study, based on three U. S. National Land Cover Databases (1992, 2001 and 2006), the landscape mosaic indicator in combination with the Markov model was adopted to analyze forest fragmentation patterns and changes in the characteristics of spatial interactions between forests and other land use types in Oregon State, USA. The results showed that conversion from the development-dominated type D to the single development type DD in landscape mosaic model had the highest transition probability 0.319, indicating that urbanization has been the major force responsible for the change of regional landscape patterns. In the forest security model, the highest rates of forest loss occurred in agriculture and the developed landscape mosaic type (ad), showing that in the development and agriculture dominated landscapes, encroaching upon forests was at the highest likelihood. The areal percentage of forest over the total study area was less than 50% when reaching a steady-state distribution, with an accelerating rate of forest fragmentation, and the landscape spatial distribution tended to be a mixed landscape pattern. The Kappa coefficient between the simulated values and the observed values from the 2006 landscape mosaic model was estimated at 0.82, indicating this model had a high precision. However, the accuracy of the forest security model was poor, with a Kappa coefficient of 0.21.

[Intravascular lymphomatosis presenting in the lung].

OBJECTIVE: To investigate the clinical, radiographic and pathological characteristics of intravascular lymphomatosis primarily manifested in the lung, without skin and central nervous system involvements. METHODS: A case of T cell intravascular lymphomatosis presenting with fever and multiple pulmonary shadows on chest radiograph was described and 14 similar cases reported in the English literature were reviewed. RESULTS: We described a case of T cell intravascular lymphomatosis, who was a 36 year old man, complained of fever and multiple pulmonary shadows on chest radiograph and admitted to Peking Union Medical College Hospital in march, 2008. Open lung biopsy showed features characteristic of intravascular lymphomatosis. He received CHOP chemotherapy, but died 20 days after diagnosis. Most cases of intravascular lymphomatosis primarily manifested in the lung occurred in older patients, ranging from 36 to 79 years of age (mean 59 years), with a male predominance (M : F = 11 : 4). The chief complaints were dyspnoea (10/15), cough (9/15), fever (5/15) and weight loss (5/15). Pulmonary function tests usually revealed some degree of decreased diffusing capacity. Eight cases had high serum lactate dehydrogenase levels. Chest CT scan showed multiple reticular or/and nodular density. Immunophenotypically, 10 cases were B cell lineage, 3 cases were T cell lineage. Six cases of B cell intravascular lymphomatosis were followed, of whom 4 and were alive, and 2 died of respiratory failure. Three cases of T cell intravascular lymphomatosis showed poor prognosis, both of whom died of respiratory failure. CONCLUSIONS: Intravascular lymphomatosis primarily manifested in the lung is a rare malignant disease. Its pulmonary symptoms were nonspecific, and pulmonary function tests and chest CT scan manifested as those of interstitial pneumonia or pulmonary infection. It can be pathologically diagnosed through transbronchial lung biopsy or surgical lung biopsy.

A homologous promoterless K-ras cDNA targeting endogenous K-ras expression inhibits human pancreatic cancer cell growth in vitro and in vivo.

It has been reported that the local introduction of a promoter-less DNA containing the complementary DNA (cDNA) sequence of a gene could induce gene-specific silencing in plants. The feasibility of this kind of silencing in human cancer cells is as yet unknown. The current study was designed to investigate the anti-tumor effects of a homologous promoterless K-ras cDNA system on pancreatic cancer. A full-length K-ras cDNA fragment was cloned into the promoterless plasmid puc19 to yield puc-K-ras. This construct was then transfected into pancreatic cancer cells. Our results demonstrated that the transfection of a promoterless K-ras cDNA resulted in a significant decrease in endogenous K-ras in a dose- and time-dependent manner and induced pancreatic cell apoptosis. Furthermore, stable puc-K-ras transfection decreased the endogenous protein level of K-ras and inhibited cell proliferation, clone formation and tumorigenicity in vivo. These findings indicate a promising application of this homologous promoterless cDNA silencing system in pancreatic cancer gene therapy.

[Promoterless DNA fragments inhibiting the expression of integrated gene in human pancreatic carcinoma cells].

OBJECTIVE: To investigate whether introducing promoterless DNA containing the cDNA sequence of green fluorescent protein (GFP) induces gene-specific silencing in human pancreatic cancer cell line harboring genomically integrated GFP gene. METHODS: Using G418 selection and fluorescent separation we established a highly purified monoclonal pancreatic cancer cell line, recombinant PANC-1, which had a steady level of GFP expression. GFP cDNA was amplified by PCR from plasmid pEGFP-C1 and ligated to the promoterless plasmid PUC19. PUC-GFP was then transfected into monoclone cells along or cotransfected with pEGFP-C1 to panc-1 cells. Each had PUC plasmid transfected group as their control to eliminate possibility of plasmid toxicity and GFP small interferent RNA (siGFP) transfected group as positive control. Western blot, flow cytometry and phase contrast fluorescence microscopy were used to detect the changes of GFP expression. RESULTS: The data showed that (1) PUC-GFP inhibited the GFP expression in monoclonal cell line in a dosage dependent manner. The inhibitory effect of 3 microg PUC-GFP did not show significant difference with siGFP. (2) The significant repression appeared on the fourth day after transfecting monoclonal cells with 3 microg PUC-GFP. By the end of the sixth day, GFP expression in PUC-GFP group and siGFP group remained at a low level. (3) Cotransfecting PUC-GFP with pEGFP-C1 plasmids into PANC-1 cells showed a decreased transfection efficiency when compared with transfecting pEGFP-C1 alone. Higher PUC-GFP vs pEGFP-C1 corresponded with lower transfection efficency. (4) When adding new pEGFP-C1 plasmid to cells after inhibition appeared, the GFP expression recovered. CONCLUSION: Transfection of the promoterless DNA fragment containing full-length cDNA effectively induces a gene-specific silencing in mammalian cells.

Tetramethylpyrazine inhibits agiontensin II-induced nuclear factor-kappaB activation and bone morphogenetic protein-2 downregulation in rat vascular smooth muscle cells.

Tetramethylpyrazine (TMP), an effective component of traditional Chinese medicine Chuanxiong, is commonly used to resolve embolism. Its possible therapeutic effect against atherosclerosis has received considerable attention recently. Angiotensin II (Ang II) is highly implicated in the proliferation of vascular smooth muscle cells (VSMCs), resulting in atherosclerosis. The mechanisms of TMP in the proliferation of VSMCs induced by Ang II remain to be defined. The present study was aimed to study the effect of TMP on Ang II-induced VSMC proliferation through detection of nuclear factor-kappaB (NF-kappaB) activity and bone morphogenetic protein-2 (BMP-2) expression. Primary cultured rat aortic smooth muscle cells were divided into the control group, Ang II group, Ang II + TMP group and TMP group. Cells in each group were harvested at different time points (15, 30 and 60 min for detection of NF-kappaB activity; 6, 12 and 24 h for measurement of BMP-2 expression). NF-kappaB activation was identified as nuclear staining by immunohistochemistry. BMP-2 expression was observed through Western blot, immunohistochemistry and in situ hybridization. The results showed that: (1) Ang II stimulated the activation of NF-kappaB. Translocation of NF-kappaB p65 subunit from cytoplasm to nucleus appeared as early as 15 min, peaked at 30 min (P<0.01) and declined after 1 h. (2) TMP inhibited Ang II-induced NF-kappaB activation (P<0.01). (3) Ang II increased BMP-2 expression at 6 h but declined it significantly at 12 and 24 h (P<0.01). (4) BMP-2 expression was also kept at high level at 6 h in Ang II + TMP group but maintained at the normal level at 12 and 24 h. (5) There was no significant difference in NF-kappaB activation and BMP-2 expression between the control group and TMP group. These results indicate that TMP inhibits Ang II-induced VSMC proliferation through repression of NF-kappaB activation and BMP-2 reduction, and BMP-2 expression is independent of the NF-kappaB pathway. In conclusion, TMP has therapeutic potential for the treatment of atherosclerosis.

Small interfering RNAs targeting mutant K-ras inhibit human pancreatic carcinoma cells growth in vitro and in vivo.

AIM: To investigate the effect of small interfering RNAs targeting mutant K-ras on the growth of pancreatic carcinoma cell lines in vitro and in vivo. MATERIALS AND METHODS: We cloned targeting sequence spanning codon 12 of mutant K-ras into the pSilencer-hygro plasmid, yielding two recombinant vectors with one base different. Both human pancreatic carcinoma cell lines were transfected by these two recombinant vectors. The transfected PC-7 cells were injected subcutaneously into nude mice to observe its tumorigenicity. RT-PCR and Western blot analysis were carried out to test the expression of K-ras in all of the transfected cell lines. Growth curves assay were performed to test the abilities of cells proliferation. Anti-K-ras therapy of PC-7 and Panc-1 in subcutaneous mice models were performed by intratumor injection of polyethylenimine/siRNAs complex. RESULTS: The expressions of K-ras in PC-7 cells and Panc-1 cells were significantly inhibited by corresponding small interfering RNAs. The expression of K-ras was particularly inactivated by siRNA without any base mismatch to its homologous mRNA, while this oncogene with central base mismatch could not be inhibited as effectively as that of the former. The growth of PC-7 cells and Panc-1 cells transfected by corresponding mutant K-ras targeted siRNAs were significantly suppressed when compared with controls (p<0.05). The transfected PC-7 cells lost tumorigenic ability. Four weeks treatment of Xenograft of pancreatic carcinoma (PC-7 and Panc-1) in nude mice with Polyethylenimine-encapsulated mutant K-ras targeted siRNAs (20 microg/mouse twice weekly) were effective in reducing tumor growth, when compared with controls (p<0.05). CONCLUSION: The central base may play a key role in the process of RNA interference. The mutant point and its vicinity of 19 nucleotides in K-ras may be the effective targeting sequence for RNA interference. Targeting mutant-k-ras therapy of pancreatic carcinoma may be a clinically applicable therapeutic modality.

[K-ras mutation analysis in ovarian serous borderline and malignant tumors].

OBJECTIVE: To investigate the roles of K-ras gene in the tumorigenesis of ovarian serous borderline and malignant tumors. METHODS: Fifty one tissue samples of ovarian serous tumors, including 18 conventional serous borderline tumors, 11 micropapillary serous borderline tumors, 12 invasive micropapillary serous carcinomas, and 10 conventional serous carcinomas were investigated for the presence of K-ras mutation. DNA was extracted after microdissection of the tumor tissue, the exon 1 of K-ras gene was amplified by PCR, and the presence of mutation at the codons 12 and 13 was evaluated by direct sequencing analysis. RESULTS: GGT to GTT mutation at codon 12 of the K-ras gene was found in one conventional serous borderline tumors, resulting in valine to glycine substitution. All other 50 cases showed no K-ras mutation. All tumors had a wild-type codon 13. CONCLUSIONS: Mutations of K-ras at codons 12 and 13 in ovarian serous tumors are very rare in this series of patients, suggesting a difference present between the Chinese and Caucasian populations. K-ras mutations may play a less important role in the tumorigenesis of ovarian serous tumor of the Chinese patients.