p53 oncogene mutations in three human prostate cancer cell lines

p53 gene structure and chromosome 17p alleles were studied in the three human prostate cancer cell lines, LNCaP, DU-145, and PC-3. Our laboratory has two separate culture lines of the LNCaP human prostate cancer cells. One strain, LNCaP-GW, had a mutation in one of two alleles at position 273 (arg > his). This mutation could not be detected in a second strain of LNCaP, LNCaP-ATCC. Immunohistochemical staining for P53 protein in the cell lines indicated that protein overexpression in LNCaP was heterogeneous, even in clonal isolates derived from LNCaP-GW that contained the codon 273 mutation in every cell. We also performed in vitro and in vivo growth analysis to compare the LNCaP-GW and LNCaP-ATCC cells. LNCaP-GW grew more rapidly than LNCaP-ATCC in vitro. However, LNCaP-ATCC formed tumors efficiently when inoculated into nude mice, whereas LNCaP-GW formed tumors much less efficiently. Consideration must be given to the notion that some of these p53 mutations arose during in vitro passage. We also confirmed published findings with two other human prostate cancer cell lines. In DU-145, two mutations were found in the p53 gene. A mutation at codon 274 (pro > leu) and a second mutation at codon 223 (val > phe) were present. PC-3 cells were hemizygous for chromosome 17p. The single copy of the p53 gene had a base pair deletion at codon 138 that generated a frame shift and a new in-frame stop codon at position 169. © 1993 Wiley-Liss, Inc.     

Detection of human papillomavirus DNA and p53 gene mutations in human prostate cancer

The relationship between integration with human papillomavirus (HPV) and p53 gene mutations in tissues of prostate cancer was examined. Tissue samples analyzed were obtained by total prostatectomy (29 stage B cancer cases) and from autopsy (22 endocrine therapy-resistant metastatic disease cases). HPV DNA was detected in 8 of 51 (16%, 5 in stage B and 3 in autopsy cases) by polymerase chain reaction (PCR) using consensus primers on L1 region. Genotypes of HPV were entirely type 16. Structural abnormalities of p53 gene were detected in 7 of the 22 autopsy cases (32%) by PCR-single-strand conformation polymorphism analysis and direct sequencing. No p53 gene mutation was found in stage B cancer cases. Analysis of mutation spectra revealed clear differences between Japanese and Westerners. There was a significant difference in the mutation frequency between stage B and autopsy cases (P < 0.01, Fisher's exact test). One case showed both integration of HPV and p53 gene mutation in different cancer foci. However, the other cases revealed an inverse correlation between the presence of HPV DNA and p53 gene mutations. These data show that p53 genetic alteration is correlated with the progression of prostate cancer, in contrast to the integration of HPV that may occur in a relatively early stage. In conclusion, this study may indicate that either p53 gene mutation or the presence of HPV's oncogenic protein E6 is involved in the development of prostate cancer. © 1996 Wiley-Liss, Inc.     

Mutations in TP53 or DNA damage repair genes define poor prognostic subgroups in primary prostate cancer

BackgroundMutations in DNA damage repair genes, in particular genes involved in homology-directed repair, define a subgroup of men with prostate cancer with a more unfavorable prognosis but a therapeutic vulnerability to PARP inhibition. In current practice, mutational testing of prostate cancer patients is commonly done late i.e., when the tumor is castration resistant. In addition, most sequencing panels do not include TP53, one of the most crucial tumor suppressor genes in human cancer. In this proof-of-concept study, we sought to extend the clinical use of these molecular markers by exploring the early prognostic impact of mutations in TP53 and DNA damage repair genes in men with primary, nonmetastatic prostate cancer undergoing radical prostatectomy (RPX).MethodsTumor specimens from a cohort of 68 RPX patients with intermediate (n = 11, 16.2%) or high-risk (n = 57, 83.8%) disease were analyzed by targeted next generation sequencing using a 37 DNA damage repair and checkpoint gene panel including TP53. Sequencing results were correlated to clinicopathologic variables as well as PSA persistence or time to PSA failure. In addition, the distribution of TP53 and DNA damage repair gene mutations was analyzed in three large publicly available datasets (TCGA, MSKCC and SU2C).ResultsOf 68 primary prostate cancers analyzed, 23 (33.8%) were found to harbor a mutation in either TP53 (n = 12, 17.6%) or a DNA damage repair gene (n = 11, 16.2%). The vast majority of these mutations (22 of 23, 95.7%) were detected in primary tumors from patients with high-risk features. These mutations were mutually exclusive in our cohort and additional data mining suggests an enrichment of DNA damage repair gene mutations in TP53 wild-type tumors. Mutations in either TP53 or a DNA damage repair gene were associated with a significantly worse prognosis after RPX. Importantly, the presence of TP53/DNA damage repair gene mutations was an independent risk factor for PSA failure or PSA persistence in multivariate Cox regression models.ConclusionTP53 or DNA damage repair gene mutations are frequently detected in primary prostate cancer with high-risk features and define a subgroup of patients with an increased risk for PSA failure or persistence after RPX. The significant adverse impact of these alterations on patient prognosis may be exploited to identify men with prostate cancer who may benefit from a more intensified treatment.     

Serial markers of bone turnover in men with metastatic prostate cancer treated with zoledronic Acid for detection of bone metastases progression

OBJECTIVES: This study assessed the usefulness of serial measurements of bone turnover markers in men with metastatic prostate cancer treated with zoledronic acid to detect disease progression. METHODS: Serum measurements of total alkaline phosphatase (tALP), bone-specific alkaline phosphatase (bALP), cross-linked N-terminal (NTx) and cross-linked C-terminal (CTx) telopeptides of type I collagen, amino-terminal procollagen propeptides of type I collagen (PINP), C-terminal telopeptides of type I collagen (ICTP), and prostate-specific antigen (PSA) were performed in 77 prostate cancer patients suffering from bone metastases and treated with zoledronic acid up to 15 mo. Fifty patients were with and 27 patients without objective evidence of metastatic bone progression during the administration of zoledronic acid. RESULTS: The baseline bone marker concentrations were not significantly different between the groups. After administration of zoledronic acid all bone markers except of ICTP decreased compared with baseline. CTx showed the greatest decrease. In patients with metastatic bone progression PINP, tALP, bALP, and ICTP were significantly higher at weeks 24, 36, 48, and 60 after starting treatment with zoledronic acid compared with patients without progression. In addition to the information of prostate-specific antigen as a monitoring parameter, the bone formation marker showed a better distinction between patients with and without disease progression. CONCLUSIONS: Selected bone turnover markers provide valuable information regarding progression of bone metastasis in men with metastatic prostate cancer under bisphosphonate therapy. The clinical impact should be confirmed in prospective randomised studies.     

p53 antibodies in the serum of patients with prostate cancer

We assessed the potential clinical utility of levels of p53-specific antibodies as a novel serum biomarker of prostate cancer that could be used in conjunction with level of PSA. Material and methods Serum levels of p53-specific antibodies in patients with relapsed, newly diagnosed prostate cancer and in patients with benign prostate hyperplasia were quantified by an enzyme-linked immunoabsorbent assay. Result There was no significant difference (P = 0.96) between the serum levels of p53-specific antibodies in patients with newly diagnosed prostate cancer and with benign prostatic hyperplasia. In the newly diagnosed prostate cancer group, stage T1c (n = 8) showed the lowest p53-specific antibody level. However, the difference between T1c group and benign prostatic hyperplasia group was not significant (P = 0.686). The relapsed cancer group tended to have low levels of the antibodies, and, there was no significant difference between the relapsed prostate cancer group and the benign prostatic hyperplasia group (P = 0.14). The serum levels of p53-specific antibodies in patients with metastatic and with localized prostate cancer showed no significant difference (P = 0.68). Conclusion The use of titers of p53-specific antibodies to make differential diagnosis between prostate cancer and benign prostatic hyperplasia might have no role, and the antibodies should not be used as a marker of prostate cancer by itself. Because our study is based on small number of patients, further studies are necessary before its absolute validity can be determined.     

Androgen-independent prostate cancer treated with resection of the solitary metastatic site

The concept of resection of a solitary metastatic lesion is quite foreign in prostate cancer, as metastases to regional lymph nodes or to other distant sites are most likely suggestive of disseminated disease. The current report demonstrates a very unique case, in whom excision of a solitary pulmonary metastasis has resulted in continued undetectable prostate-specific antigen values over 3 years after resection. Nevertheless, the presence of unusual cases such as this, as well as the work of others, may suggest that surgical excision of solitary or oligometastatic sites could at least be considered for the most highly selected and well-informed patients, whose clinical scenario indicates a potential benefit from such an approach.     

p53 overexpression and K-ras gene mutations in primary sclerosing cholangitis-associated biliary tract cancer

Cholangiocarcinoma occurs frequently in patients with primary sclerosing cholangitis (PSC). We evaluated the incidence and prognostic significance of p53 protein overexpression and K-ras gene mutations in patients with biliary tract cancer and PSC. p53 protein expression was determined in specimens from 12 patients with biliary tract cancer, using the antibody, D07. K-ras mutations were detected using DNA sequencing and a mutation ligation assay. Accumulation of p53 protein was detected in 6 of 12 tumors (50%). K-ras mutations were detected in 4 of 12 tumors (33%). Overall survival in patients with p53-negative tumors was significantly longer (P < 0.05) than that in patients with p53-positive (mutant) tumors. Similarly, overall survival was significantly longer (P < 0.05) in the absence of a K-ras mutation than in patients with a tumor containing a K-ras mutation. Mean interval from the time of diagnosis of PSC until the diagnosis of biliary tract cancer was significantly shorter (P < 0.05) in patients with p53 overexpression than in those patients without p53 overexpression (2 versus 47 months). p53 overexpression and K-ras mutations occur commonly in patients with PSC and biliary tract cancer and are associated with a shortened survival. Patients with longstanding PSC are less likely to have these genetic alterations and may have a better prognosis. Received: September 24, 1999 / Accepted: June 6, 2000     

前列腺癌并骨转移的治疗新进展

正在所有男性恶性肿瘤的发病率中,前列腺癌发病率在全球居第2位,癌症特异性死亡居第6位[1]。随着人口老龄化的加剧、生活方式变化以及前列腺特异性抗原(prostate-specific antigen,PSA)筛查的推广,我国前列腺癌的发病率也呈现攀升的态势,2011年中国前列腺癌发病率居恶性肿瘤第9位[2]。在我国,由于PSA筛查尚未普及,前列腺癌在首次发现时就已经发生了骨转移较为常见,这在基层单位尤其明显。近年来,对于骨寡转移患者除     

Osteoblasts produce soluble factors that induce a gene expression pattern in non-metastatic prostate cancer cells, similar to that found in bone metastatic prostate cancer cells

BACKGROUND: Progressive prostate cancer typically metastasizes to bone where prostate cancer cells gain an osteoblast-like phenotype and induce osteoblastic metastases through unknown mechanisms. To investigate the biology of prostate cancer skeletal metastases, we compared gene expression between the non-metastatic LNCaP cell line and its derivative cell line C4-2B that metastasizes to bone. METHODS: Total RNA from LNCaP and C4-2B cell lines was isolated and used to probe membrane-based gene arrays (Comparison 1). Additionally, LNCaP cells were incubated in the absence or presence of conditioned media (CM) from a human osteoblast-like cell line (HOBIT) and total RNA from these cells was used to probe gene arrays (Comparison 2). Differential expression of genes was confirmed by RT-PCR. RESULTS: Of the 1,176 genes screened, 35 were differentially expressed between LNCaP and C4-2B cells (Comparison 1). HOBIT-CM induced differential expression of 30 genes in LNCaP cells (Comparison 2). Interestingly, 19 genes that were differentially expressed in C4-2B vs. LNCaP also displayed a similar expression pattern in LNCaPs grown in HOBIT-CM. These genes are primarily involved in motility, metabolism, signal transduction, tumorigenesis, and apoptosis. CONCLUSIONS: These results suggest that osteoblasts produce soluble factors that contribute to the progression of prostate cancer skeletal metastases, including their transition to an osteoblast-like phenotype. Additionally, these data provide targets to explore for further investigations towards defining the biology of skeletal metastases.     

乳腺癌中p53基因DNA水平突变与核蛋白水平突变的比较

目的研究ｐ５３基因ＤＮＡ水平和蛋白水平的突变。方法分别采用多聚酶链反应单链构象多态分析银染方法和链酶亲和素生物素过氧化物酶复合物（ｓｔｒｅｐａｖｉｄｉｎｂｉｏｔｉｎｐｅｒｏｘｉｄａｓｅｃｏｍｐｌｅｘ,ＳＡＢＣ）免疫组化方法,检测了５４例乳腺浸润性导管癌标本。结果２２例在ＤＮＡ水平突变阳性,突变率为４１％;３２例在核蛋白水平突变,突变率５７％。其中２２例ＤＮＡ突变阳性者,核蛋白突变均阳性;而３２例ＤＮＡ水平突变阴性者,核蛋白突变阳性者９例,占２８％。ｐ５３ＤＮＡ突变与核蛋白突变之间有显著相关性,并且两者都与患者的淋巴结转移以及雌、孕激素受体表达有关（Ｐ＜００１）。结论免疫组化是一种快速检测ｐ５３是否存在异常的有效方法。但是在蛋白水平突变阳性者中存在一定的假阳性。ｐ５３突变阳性患者预后较差     

Experience with sunitinib in hormone-resistant metastatic prostate cancer that is unresponsive to docetaxel

Introductionsystemic treatment options for patients with hormone-refractory prostate cancer (HRPC) that progress despite the use of Docetaxel are very limited. One of the options of compassionate use currently available is the use of Sunitinib. We present a joint preliminary experience with the use of Sunitinib in this clinical case.Patients and methodsa series of eight cases is presented, which sets forth a prospective multicentre experience with Sunitinib in patients with hormone-refractory metastatic and progressive prostate cancer, previously treated with at least a regime of Docetaxel-based chemotherapy. Other alternative chemotherapy regimes had already been tried in some patients. The primary objective of our study was the PSA response rate and our secondary objective was the progression-free period. We administered a dosage of 50 mg/day for four-week cycles, followed by a two-week rest per cycle, until we reached a total of eight cycles or up to clinical progression or intolerable toxicity.Resultsin four cases, the PSA dropped to below 50% of the baseline level at the beginning of the treatment, and five patients presented some decrease in PSA. The progression-free time was 16.4 weeks. Toxicity arising from the treatment was moderate and manageable.Conclusionsdespite the limits of this experience, we can say that Sunitinib appears to be an active and safe option in patients with hormone-refractory prostate cancer that is resistant to chemotherapy with Docetaxel.     

Src as a therapeutic target in men with prostate cancer and bone metastases

While responsive to androgen ablation in its early stages, prostate cancer eventually becomes castration‐resistant and metastasizes preferentially to bone. Once this happens, the disease carries considerable morbidity and is incurable. The process of bone metastasis involves a complex interplay between tumour and bone tissue. The eventual characteristic clinical presentation of disorganized osteoblastic bone lesions is preceded by a facilitatory osteoblastic phase; an osteoblastic component then continues to underlie the process. Increasing evidence has shown a ubiquitous role for Src (a proto‐oncogene tyrosine‐protein kinase) in multiple tumour and bone‐signalling processes involved in prostate tumour progression, driving proliferation, survival, migration and transition to androgen‐independent growth. It is also intimately involved in positively regulating osteoclast physiology. As such, this molecule represents an attractive target for managing progressing prostate cancer. Encouraging results have been obtained in preclinical and clinical studies using Src inhibitors like AZD0530 and dasatinib. Both compounds reduced markers of bone resorption, in patients with cancer and those with advanced castration‐resistant prostate cancer, respectively. Moreover, because Src is central to many mechanisms thought to be responsible for the development of castration resistance, adding Src inhibitors to a treatment regimen might reverse this phenomenon. As a result, many Src inhibitors are in preclinical development. This review explores Src inhibition as a strategy for managing bone metastasis in prostate cancer, with a particular focus on targeting the critical osteoclastic response. Other emerging and novel approaches are also considered.