Displaying publications 1 - 20 of 380 in total

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  1. Wang PL, Peh SC
    Malays J Pathol, 1997 Jun;19(1):59-64.
    PMID: 10879243
    The International Working Formulation divides non-Hodgkin's lymphoma (NHL) into three grades: low, intermediate and high. This grading system implies rate of tumour growth and hence prognosis. Ki-67 antigen is a proliferation-related nuclear antigen and bcl-2 oncogene product is known to inhibit apoptosis. This study aimed to determine the pattern of expression of Ki-67 antigen and bcl-2 oncoprotein in various grades of NHL. Paraffin-embedded tissues from 42 cases of NHL (7 low, 15 intermediate, 20 high grade) were retrieved from the files of the Department of Pathology, University of Malaya. Ki-67 antigen and bcl-2 oncoprotein were detected using immunohistochemistry. The percentage of positively stained neoplastic cells was determined by semi-quantitative estimation and given scores ranging from 0 to 6. Partition chi square test demonstrated the association of Ki-67 antigen expression and histological grade (p = 0.007). There was no significant difference in Ki-67 antigen expression between intermediate and high grade malignant lymphomas (p = 0.28), whereas significant difference was demonstrated between low and intermediate/high grade tumours (p = 0.003). Bcl-2 oncoprotein expression in the neoplastic cells varied widely within the three histological grades. Statistical analysis showed no association between the expression of bcl-2 oncoprotein and histological grade (p = 0.25). Ki-67 immunostaining is therefore a useful adjunct to histological grading of NHL.
    Matched MeSH terms: Proto-Oncogene Proteins c-bcl-2/metabolism*
  2. Padmanathan A, Yadav M, Gregory AR, Kumar S, Norhanum AW
    Med J Malaysia, 1997 Jun;52(2):108-16.
    PMID: 10968067
    The present study was undertaken to evaluate the prevalence of HPV in formalin-fixed, paraffin-embedded cervical carcinoma tissues using PCR followed by non-radioactive Southern hybridization with type-specific oligonucleotides for HPV 16 and 18. In addition, the tissue sections were immunohistochemically screened with two monoclonal antibodies, for expression of HPV 16 L1 and HPV 18 E6 proteins. A total of 57 of 60 cervical carcinomas (95.0%) were found with HPV using both techniques. HPV 16 and HPV 18 were present in equal proportions. Results of both DNA hybridization and immunohistochemistry were in agreement for the majority of the cases. HPV 16 and 18 DNA and virus-encoded antigens, L1 and E6 were found highly prevalent in these cervical carcinomas. Due to the high prevalence of HPV with cervical carcinoma in Malaysia, the implementation of routine diagnosis for the virus in cervical biopsies would be clinically useful.
    Matched MeSH terms: Oncogene Proteins, Viral/analysis*
  3. Naidu R, Yadav M, Nair S, Kutty MK
    Br. J. Cancer, 1998 Nov;78(10):1385-90.
    PMID: 9823984
    Expression of c-erbB3 protein was investigated in 104 primary breast carcinomas comprising nine comedo ductal carcinoma in situ (DCIS), 91 invasive ductal carcinomas and four invasive lobular carcinomas using two monoclonal antibodies, RTJ1 and RTJ2. Of the 91 invasive ductal carcinomas, seven contained the comedo DCIS component adjacent to the invasive component. An immunohistochemical technique was used to evaluate the association between expression of c-erbB3 and clinical parameters and tumour markers such as epidermal growth factor receptor (EGFR), c-erbB2, cathepsin-D and p53 in archival formalin-fixed paraffin-embedded tumour tissues. Our results indicated that RTJ1 and RTJ2 gave identical staining patterns and concordant results. It was found that the overexpression of c-erbB3 protein was observed in 67% (6/9) of comedo DCIS, 52% (44/84) of invasive ductal carcinomas, 71% (5/7) of carcinomas containing both the in situ and invasive lesions and 25% (1/4) of invasive lobular carcinomas. A significant relationship (P < 0.05) was observed between strong immunoreactivity of c-erbB3 protein and histological grade, EGFR and cathepsin-D, but not with expression of c-erbB2, p53, oestrogen receptor status, lymph node metastases or age of patient. However, we noted that a high percentage of oestrogen receptor-negative tumours (59%), lymph node-positive tumours (63%) and c-erbB2 (63%) were strongly positive for c-erbB3 protein. We have also documented that a high percentage of EGFR (67%), c-erbB2 (67%), p53 (75%) and cathepsin-D-positive DCIS (60%) were strongly positive for c-erbB3. These observations suggest that overexpression of c-erbB3 protein could play an important role in tumour progression from non-invasive to invasive and, also, that it may have the potential to be used as a marker for poor prognosis of breast cancer.
    Matched MeSH terms: Proto-Oncogene Proteins/genetics*
  4. Naidu R, Wahab NA, Yadav M, Kutty MK, Nair S
    Int J Mol Med, 2001 Aug;8(2):193-8.
    PMID: 11445874
    Amplification of int-2/FGF-3 gene was investigated by differential polymerase chain reaction (dPCR) in 440 archival primary breast carcinoma tissues. Of these, 23 were comedo ductal carcinoma in situ (DCIS), 18 were non-comedo DCIS, 41 were comedo DCIS with adjacent invasive ductal carcinomas, 19 were non-comedo DCIS with adjacent invasive ductal carcinomas, 270 were invasive ductal carcinomas, 33 were invasive lobular carcinomas, 21 were colloid carcinomas and 15 were medullary carcinomas. Int-2 was amplified in 22% (96/440) of the primary breast carcinomas. It was shown that int-2 was amplified in 13% (3/23) of the comedo DCIS, 17% (7/41) of the comedo DCIS and 29% (12/41) of the adjacent invasive ductal carcinomas, 26% (71/270) of the invasive ductal carcinomas, 18% (6/33) of the invasive lobular carcinomas, 10% (2/21) of the colloid carcinomas and 13% (2/15) of the medullary carcinomas. In contrast, int-2 was not amplified in non-comedo DCIS and invasive ductal carcinomas with adjacent non-comedo DCIS lesions. A significant association was observed between int-2 amplification in the in situ components and adjacent invasive lesion (P<0.05). All tumors with int-2 amplification in the in situ lesions (7/7) also demonstrated same degree of amplification in the adjacent invasive components. However, 9% (5/53) of the tumors with no amplified int-2 gene in the in situ components showed int-2 amplification in the adjacent invasive lesions. A significant relationship was noted between amplification of int-2 and lymph node metastases (P<0.05) and poorly differentiated tumors (P<0.05) but not with estrogen receptor status (P>0.05) and proliferation index (Ki-67 and PCNA) (P>0.05). In Malaysia, majority of the patients belong to younger age group (<50 years old) but a comparison of the age groups showed that the amplification of int-2 was not statistically associated with patient age (P>0.05). These observations indicate that amplification of int-2 tends to strengthen the view that int-2 may have the potential to be an indicator of poor prognosis regardless of the age of the patient. Moreover, the presence of int-2 amplification in preinvasive, preinvasive and adjacent invasive lesions, and invasive carcinomas suggest that int-2 could be a marker of genetic instability occurring in early and late stages of tumor development.
    Matched MeSH terms: Proto-Oncogene Proteins/genetics*
  5. Ahmad AH, Ismail Z
    Malays J Med Sci, 2002 Jan;9(1):3-8.
    PMID: 22969311 MyJurnal
    The discovery that c-fos, a proto-oncogene, has a role in pain, has triggered extensive research on the consequences of c-fos expression. It has been shown that c-fos, through its protein form, FOS, leads to expression of dynorphin gene and subsequently dynorphin protein which is implicated in the development of a pain state. This mini review looks at the properties of c-fos and the consequences of its expression following noxious (painful) stimulation.
    Matched MeSH terms: Proto-Oncogene Proteins c-fos
  6. Naidu R, Wahab NA, Yadav M, Kutty MK
    Int J Mol Med, 2002 Feb;9(2):189-96.
    PMID: 11786932
    Overexpression of c-myc protein and amplification of c-myc were investigated by immunohistochemistry and differential polymerase chain reaction (dPCR) in 440 formalin-fixed primary breast carcinoma tissues, respectively. Overexpression of c-myc was detected in 45% (199/440) and amplification of c-myc was observed in 25% (112/440) of the primary breast carcinomas. Immunolocalization of c-myc oncoprotein was demonstrated in 35% (8/23) of the comedo subtype, 17% (3/18) of the non-comedo subtype, 37% (15/41) of the comedo DCIS and 49% (20/41) of the adjacent invasive ductal carcinomas, 21% (4/19) of the non-comedo DCIS and 37% (7/19) of the adjacent invasive lesions, 49% (133/270) of the invasive ductal carcinomas, 33% (11/33) of the invasive lobular carcinomas, 29% (6/21) of the colloid carcinomas and 47% (7/15) of the medullary carcinomas. C-myc was amplified in 13% (3/23) of the comedo DCIS, 17% (7/41) of the comedo DCIS and 24% (10/41) of the adjacent invasive ductal carcinomas, 30% (82/270) of the invasive ductal carcinomas, 21% (7/33) of the invasive lobular carcinomas, 14% (3/21) of the colloid carcinomas and 24% (4/15) of the medullary carcinomas. Amplification of c-myc was noted in 16% (3/9) of the invasive ductal carcinomas but not in the adjacent non-comedo DCIS lesions. A significant association (P<0.05) was observed between in situ components and adjacent invasive lesions for c-myc expression and amplification. Overexpression of c-myc protein was significantly correlated with poorly differentiated (P<0.05) and high proliferation index (Ki-67) (P<0.05) tumors but not with lymph node metastases (P>0.05), patient age (P>0.05) and estrogen receptor status (P>0.05). Significant relationship was also noted between amplification of c-myc and absence of estrogen receptor (P<0.05), high histological grade (P<0.05) and high proliferation index (Ki-67) (P<0.05). No relationship was seen with nodal status (P>0.05) and patient age (P>0.05). Majority of the Malaysian female patients are from younger age group (<50 years old) but overexpression and amplification of c-myc was not statistically associated with patient age (P>0.05) indicating that these alterations may be independent events of patient age. The above observations suggest that overexpression and amplification of c-myc could play an important role in tumor progression from non-invasive to invasive and, also, it may have the potential as a marker of poor prognosis of breast cancer.
    Matched MeSH terms: Proto-Oncogene Proteins c-myc/analysis*; Proto-Oncogene Proteins c-myc/genetics; Proto-Oncogene Proteins c-myc/immunology
  7. Peh SC, Shaminie J, Poppema S, Kim LH
    Singapore Med J, 2003 Apr;44(4):185-91.
    PMID: 12952030
    Castleman's disease is an uncommon disease and the histopathogenesis is poorly understood. This study aims to investigate their clinicopathological and immunophenotypic profile.
    Matched MeSH terms: Proto-Oncogene Proteins/metabolism; Proto-Oncogene Proteins c-bcl-6
  8. Chien AL, Pihie AH
    J. Biochem. Mol. Biol., 2003 May 31;36(3):269-74.
    PMID: 12787481
    In the fight against cancer, novel chemotherapeutic agents are constantly being sought to complement existing drugs. Various studies have presented evidence that the apoptosis that is induced by these anticancer agents is implicated in tumor regression, and Bcl-2 family genes play a part in apoptosis following treatment with various stimuli. Here, we present data that a styrylpyrone derivative (SPD) that is extracted from the plant Goniothalamus sp. showed cytotoxic effects on the human breast cancer cell line MCF-7. SPD significantly increased apoptosis in MCF-7 cells, as visualized by phase contrast microscopy and evaluated by the Tdt-mediated dUTP nick end-labeling assay and nuclear morphology. Western blotting and immunostaining revealed up-regulation of the proapoptotic Bax protein expression. SPD, however, did not affect the expression of the anti-apoptotic protein, Bcl-2. These results, therefore, suggest SPD as a potent cytotoxic agent on MCF-7 cells by inducing apoptosis through the modulation of Bax levels.
    Matched MeSH terms: Proto-Oncogene Proteins/metabolism*; Proto-Oncogene Proteins c-bcl-2*
  9. Omar E, Othman NH
    Med J Malaysia, 2003 Aug;58(3):461-2.
    PMID: 14750392
    Matched MeSH terms: Oncogene Proteins/genetics*; Proto-Oncogene Proteins c-ret
  10. Ariffin H, Chen SP, Wong HL, Yeoh A
    Singapore Med J, 2003 Oct;44(10):517-20.
    PMID: 15024455
    In childhood acute lymphoblastic leukaemia (ALL), cytogenetics play an important role in diagnosis, allocation of treatment and prognosis. Conventional cytogenetic analysis, involving mainly karyotyping in our experience, has not been successful in a large proportion of cases due to inadequate metaphase spreads and poor chromosome morphology. Our aim is to develop a highly sensitive and specific method to screen simultaneously for the four most frequent fusion transcripts resulting from specific chromosomal translocations, namely, both the CML- and ALLtype BCR-ABL transcripts of t(9;22), E2A-PBX1 transcript of t(1;19), the MLL-AF4 transcript of t(4;11) and TEL-AML1 (also termed ETV6-CBFA2) of the cryptic t(12;21). A multiplex reverse transcription polymerase chain reaction protocol (RT-PCR) was developed and tested out on archival bone marrow samples and leukaemia cell lines. In all samples with a known translocation detected by cytogenetic techniques, the same translocation was identified by the multiplex-PCR assay. Multiplex RT-PCR assay is an effective, sensitive, accurate and cost-effective diagnostic tool which can improve our ability to accurately and rapidly risk-stratify patients with childhood ALL.
    Matched MeSH terms: Oncogene Proteins, Fusion/genetics*
  11. Kim LH, Nadarajah VS, Peh SC, Poppema S
    Histopathology, 2004 Mar;44(3):257-67.
    PMID: 14987230 DOI: 10.1111/j.0309-0167.2004.01829.x
    AIMS: To examine the expression of the Bcl-2 family of proteins (Bcl-2, Bcl-x, Bcl-xL and Bax) in classical Hodgkin's lymphoma (cHL) and to correlate the expression of these proteins with proliferation, apoptosis and the presence of Epstein-Barr virus (EBV).

    METHODS AND RESULTS: Expression of the Bcl-2 family of proteins was detected by immunohistochemistry, proliferation was determined by Ki67 labelling and apoptosis by TUNEL in-situ hybridization. EBV was detected by Epstein-Barr virus early RNA (EBER) in-situ hybridization. Expression of Bcl-2, Bcl-x, Bcl-xL and Bax was detected in the Hodgkin/Reed-Sternberg (H/RS) cells in 43.7% (27/62), 87.5% (56/64), 67.2% (41/61) and 74.6% (47/63) of the cHL cases, respectively. EBER was detected in 53% (35/66) of the cases, whereas Ki67 was observed in 86.7% (52/60) of the cases. Apoptotic H/RS cells were observed infrequently, and only 43.2% (11/26) of the cases showed an apoptotic index of > or = 10% in the H/RS cells. A statistically significant inverse relationship was observed between the expression of Bcl-2 and the presence of EBV (P = 0.003). Bcl-xL showed an inverse correlation with apoptosis in the H/RS cells (P = 0.004).

    CONCLUSIONS: The higher Bcl-xL expression (67.2%) compared with Bcl-2 expression (43.5%) observed in cHL as well as the statistically significant inverse relationship between Bcl-xL and apoptosis suggests that Bcl-xL plays an important role in the survival of H/RS cells. Expression of Bax may be neutralized by other anti-apoptotic members of the family such as Bcl-2 and/or Bcl-xL.
    Matched MeSH terms: Proto-Oncogene Proteins/biosynthesis; Proto-Oncogene Proteins c-bcl-2/biosynthesis*
  12. Omar E, Madhavan M, Othman NH
    Pathology, 2004 Apr;36(2):152-9.
    PMID: 15203751
    To investigate RET and p53 expression in local thyroid lesions, in order to shed light on the pathogenesis of papillary carcinoma and explain the high prevalence of this condition among the nodular hyperplasia (multi-nodular goitre) cases.
    Matched MeSH terms: Proto-Oncogene Proteins/metabolism*; Proto-Oncogene Proteins c-ret
  13. Khor TO, Gul YA, Ithnin H, Seow HF
    Cancer Lett, 2004 Jul 16;210(2):139-50.
    PMID: 15183529
    The enhancement of cell proliferation and promotion of cell survival via the inhibition of apoptosis is thought to be the key to the initiation and progression of cancers. The phosphatidylinositol-3 kinase (PI3K)/Akt is an important survival signal pathway that has been shown to be crucial in the regulation of balance between pro-apoptotic and survival (anti-apoptotic) signal. In this study, the expression of phosphorylated Akt at Thr308 and Ser473, BCL-2-antagonist of cell death (BAD) at Ser136 and glycogen synthase kinase-3beta (GSK-3beta) at Ser9 in 47 paraffin-embedded human colorectal carcinoma (CRC) tissues were determined by immunohistochemical staining in order to dissect the alterations in the signal transduction pathways in CRC. Our results showed that there was a significant increase in the expression of these biomolecules in CRC tissues compared to the apparently normal adjacent tissues. The frequency of increased expression in tumor colonic mucosa were as follows: p-Akt1/2/3 (Thr308) = 16/47 (34%); p-Akt1 (Ser473) = 21/47 (44.7%); phospho-BAD (p-BAD) Ser136 = 27/47 (57.4%) and phospho-GSK-3beta (p-GSK-3beta) = 21/47 (44.7%). Analysis of the total p-Akt1 (Ser473), p-Akt1/2/3 (Thr308), p-GSK-3beta (Ser9) and p-BAD (Ser136) score found that there was a statistically significant relationship with each other. A statistically significant positive linear relationship was found between total p-Akt (Ser473) score and total p-GSK-3beta (Ser9) score as well as with total p-BAD (Ser136) score. On the other hand, total p-Akt1/2/3 (Thr308) scores had a statistically significant positive linear relationship with p-GSK-3beta (Ser9) only. The Akt targets, p-GSK-3beta (Ser9) and p-BAD (Ser136) were positively correlated to each other. There was no significant correlation between clinico-pathological data with total p-Akt1 (Ser473), p-Akt1/2/3 (Thr308), p-GSK-3beta (Ser9) and p-BAD (Ser136) score except for age. The total scores of p-GSK-3beta were found to be higher in patients in the age group of greater than 60. This is the first report of p-Akt1/2/3 (Thr308) and p-BAD (Ser136) expression in primary colorectal tumor tissue. Our data further supports the role of PI3K/Akt signaling pathways in the pathogenesis of CRC and contributes to the identification of target molecules in the signal transduction pathway for cancer therapy.
    Matched MeSH terms: Proto-Oncogene Proteins/biosynthesis*; Proto-Oncogene Proteins/metabolism*; Proto-Oncogene Proteins c-bcl-2/genetics*; Proto-Oncogene Proteins c-akt
  14. Peh SC, Shaminie J, Tai YC, Tan J, Gan SS
    Histopathology, 2004 Nov;45(5):501-10.
    PMID: 15500654
    Follicular lymphoma is frequently associated with t(14;18)(q32;q21) translocation. This study was undertaken to determine the pattern of Bcl-2, CD10 and Bcl-6 expression in relation to t(14;18) translocation in follicular lymphoma from a cohort of a multi-ethnic Asian population.
    Matched MeSH terms: Proto-Oncogene Proteins/genetics; Proto-Oncogene Proteins/metabolism; Proto-Oncogene Proteins c-bcl-2/genetics; Proto-Oncogene Proteins c-bcl-2/metabolism; Proto-Oncogene Proteins c-bcl-6
  15. Gill HK, Keoh TS, Dhaliwal JS, Moore S, Kim TS, Hassan R, et al.
    Cancer Genet. Cytogenet., 2005 Jan 15;156(2):129-33.
    PMID: 15642392
    Eighty-eight multi-ethnic Malaysian pediatric acute lymphoblastic leukemia (ALL) patients were screened for the TEL-AML1 rearrangement by reverse transcription-polymerase chain reaction (RT-PCR). Fluorescence in situ hybridization (FISH) was used as an independent screen for 30 cases and to confirm RT-PCR positive cases. Seventeen patients, or 19%, were found to be t(12;21) positive. Ethnically the group comprised 12 Malays, 4 Chinese, and 1 Indian. All patients, including 1 with an unusual blast cell morphology who suffered an early relapse and death, were characteristic TEL-AML1 cases in cell count, age, ALL subset classification, and fusion transcript expressed. This study shows that in Malaysia, TEL-AML1 is found in the same distinct ALL subset and at a similar frequency as in other diverse childhood ALL cohorts.
    Matched MeSH terms: Oncogene Proteins, Fusion/genetics*
  16. Rekha K, Malini A, Xavier R, Baba K
    Med J Malaysia, 2005 Mar;60(1):41-5.
    PMID: 16250278
    The study of apoptosis in endometrium of women with irregular uterine bleeding and its predictive value in endometrial malignancy. Analyze apoptotic and mitotic indices and their relevance in irregular uterine bleeding. To determine the expression of Bcl-2 oncoprotein in endometrial glands from patients with irregular uterine bleeding. Department of pathology in a Government Hospital serving a varied socio-economic population in Chennai. Random samples of endometrial currettings from dysfunctional uterine bleeding (DUB) patient who underwent endometrial curettage as therapeutic and diagnostic procedure during the year 2000. Of 50 cases of endometrial samples from patients diagnosed as cases of DUB, the apoptotic and mitotic indexing was carried out and histological categorization revealed 13 cases as Anovulatory. 14 as simple hyperplasia, 5 as early secretory endometrium, 4 as mid secretory and 4 as late secretory endometrium and 7 as endometrium showing features of hormonal imbalance. Three cases were not included, due to sub-optimal processing. A good correlation of the Bcl-2 expression and the apoptotic cell morphology/indices, in the different categories of the endometria of DUB cases is observed. This preliminary study gives an insight to the existence of a correlative pattern of apoptosis in DUB cases. A prospective study on a larger number of cases may substantiate the hypothesis that the Apoptotic and Mitotic indices are useful screening methods with predictive values on development of endometrial carcinoma. It is observed that an increased apoptotic index correlating with high Bcl-2 expression, reflecting the actual cell burden. This prolonged cell survival resisting cell deletion is associated with irregular uterine bleeding endometria.
    Matched MeSH terms: Proto-Oncogene Proteins c-bcl-2/metabolism*
  17. Khoo JJ, Gunn A
    Malays J Pathol, 2005 Jun;27(1):9-16.
    PMID: 16676687
    AIM: To study the clinical features, histology and immunohistochemical properties of gastrointestinal stromal tumours (GISTs); and establish any parameters that can help prognosticate the malignant potential.
    METHODS: Twenty-six patients with GISTs who were seen in Sultanah Aminah Hospital Johor, Malaysia from 1999 to 2003 were selected for study. Patient, clinical characteristics and outcome based on surgical records were analysed. Tumour variables (tumour size, cellularity, mitotic count, necrosis and haemorrhage) were compared between very low to low risk groups and intermediate to high risk groups. The immunohistochemical properties of GISTs were also studied.
    RESULTS: Patients with GISTs presented mainly with pain, palpable mass or gastrointestinal tract bleeding. The tumours were seen in stomach (50%) followed by small intestine (38.5%) and rectum (11.5%). In the period of study, six patients had metastasis, mainly in the liver or peritoneum. Immunoreactivity for CD117, CD34, vimentin, S100, neuron specific enolase, alpha-smooth-muscle-actin and desmin were observed in 100%, 76.9%, 61.5%, 46.1%, 80.8%, 11.5% and 0% of tumours respectively. The behaviour of GISTs was largely dependent on tumour size and number of mitosis. Necrosis and haemorrhage were seen in tumours with high risk potential.
    Matched MeSH terms: Proto-Oncogene Proteins c-kit/immunology; Proto-Oncogene Proteins c-kit/metabolism
  18. Tey BT, Al-Rubeai M
    J Biosci Bioeng, 2005 Sep;100(3):303-10.
    PMID: 16243281
    Chemostat cultures of NS0 cell lines were carried out at dilution rates ranging from 0.8 d(-1) to 0.2 d(-1). Compared with the control, the viable cell density of the Bcl-2 cell line was approximately 10% higher at 0.8 d(-1) and increased to 55% when the dilution rate was reduced to 0.2 d(-1). As the dilution rate was reduced, the viability of the two cultures diverged reaching a difference of 43% at 0.2 d(-1). The specific growth rate of the control cells was the same as the dilution rate down to a value of 0.6 d(-1). By contrast, the specific growth rate of Bcl-2 cells was parallel to the dilution rate down to a value as low as 0.3 d(-1). For both NS0 cell lines, the G1 cell population decreased, while the S and G2/M cell populations increased as the dilution rate was reduced. The antibody titer of the control cells increased from 7 to 21 microg.ml(-1) as the dilution rate was reduced from 0.8 to 0.2 d(-1). With an initial increase from 2 to 15 microg.ml(-1) as the dilution rate was reduced from 0.8 to 0.4 d(-1), the antibody titer of the Bcl-2 cells remained constant as the dilution rate was further reduced to 0.2 d(-1). A good correlation between specific antibody production rate and the percentage of G2/M cells was observed.
    Matched MeSH terms: Proto-Oncogene Proteins c-bcl-2/genetics; Proto-Oncogene Proteins c-bcl-2/metabolism*
  19. Lim KP, Sharifah H, Lau SH, Teo SH, Cheong SC
    Oncol Rep, 2005 Oct;14(4):963-8.
    PMID: 16142358 DOI: 10.3892/or.14.4.963
    The majority of global incidences of oral cancer occur in Asia, and the aetiology of oral cancer is different in Asia as it is in the West. However, whereas there is a growing understanding of the molecular mechanisms of oral cancer progression in the West, there is little progress in this understanding in Asia. In particular, the role of the p53 pathway in modulating cancer progression in Asian oral cancer remains unclear. In this study, we micro-dissected and analysed 20 well-differentiated oral squamous cell carcinoma specimens for alterations in the p53 pathway. We found that 6/20 samples contained mutations in the p53 gene which occurred in three hotspots, at codon 203, 218 and 296. Furthermore, 6/20 samples had a homozygous deletion of p14ARF, but notably p14ARF deletion and p53 mutation events were often independent and mutually exclusive. Strikingly, MDM2 was upregulated in 20/20 samples, but not in 3/3 normal tissue specimens. Taken together, these data suggest that inactivation of the p53 pathway is a frequent event in oral squamous cell carcinoma, which occurs by an aberration in one of a number of players in the p53 pathway.
    Matched MeSH terms: Proto-Oncogene Proteins c-mdm2/metabolism*
  20. Ismail N, Pihie AH, Nallapan M
    Anticancer Res, 2005 May-Jun;25(3B):2221-7.
    PMID: 16158967
    Xanthorrhizol is a sesquiterpenoid compound extracted from Curcuma xanthorrhiza, which is known locally as Temulawak. Traditionally, C. xanthorrhiza was found to have antibacterial, anticancer and anti-inflammatory activity. The rhizome has also been used to treat inflammation in postpartum uterine bleeding. An antiproliferative assay using methylene blue staining revealed that xanthorrhizol inhibited the proliferation of the cervical cancer cell line HeLa with an EC50 value of 6.16 microg/ml. Xanthorrhizol significantly increased apoptosis in HeLa cells, as evaluated by the Tdt-mediated dUTP nick end-labelling (TUNEL) assay and nuclear morphology by Hoechst 33258 staining. Western blot analysis, which was further confirmed by the immunostaining results, implied an up-regulation of tumor suppressor protein p53 and the pro-apoptotic protein Bax, following the treatment with xanthorrhizol. Xanthorrhizol, however, did not affect the expression of the anti-apoptotic protein, Bcl-2 and the viral oncoprotein, E6. Hence, xanthorrhizol is a promising antiproliferative and anticancer agent which induces p53 and Bax-dependent apoptosis in HeLa cervical cancer cells.
    Matched MeSH terms: Proto-Oncogene Proteins c-bcl-2/biosynthesis*; Proto-Oncogene Proteins c-bcl-2/genetics
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