Biomedical subjects

Heidi L Miller

Publications and source records attributed to Heidi L Miller.

5 recordsLinked to original sources

PubMed2006

In combination, nucleoside reverse transcriptase inhibitors have significant effects on 3T3-L1 adipocyte lipid accumulation and survival.

The use of nucleoside reverse transcriptase inhibitors (NRTIs) for the treatment of HIV infection is clearly linked to the development of subcutaneous fat atrophy. Until recently, however, in vitro studies of adipocytes have shown no or only modest and inconsistent effects of these agents on adipocyte biology. This is in contrast to the protease inhibitors (PIs), which are also linked to the development of HIV lipodystrophy. These agents have relatively consistent inhibitory effects on the differentiation of cultured adipocytes, and have occasionally been found to have other effects on adipocyte biology as well. We aimed to explore more thoroughly the effects of NRTIs and combinations of antiretroviral agents commonly used in clinical practice on multiple aspects of adipocyte biology using the 3T3-L1 adipocyte cell line. We found that when used individually, NRTIs decrease cell survival but only lamivudine significantly alters lipid accumulation. However, NRTI and dual NRTI-PI combinations do significantly decrease lipid accumulation in 3T3-L1 adipocytes, have a much greater detrimental impact on cell survival and decrease adipocyte differentiation.

3T3-L1 Cells↗

PubMed2004

Biomorphometric analysis of human prostatic carcinoma by using three-dimensional computer models.

Advances in the detection of carcinoma of the prostate during the last 15 years have accounted for a sharp increase and then an abrupt decrease in the incidence of the disease. A more recent decline in its mortality rates has been variously interpreted as either the success of early detection and improved treatment or lead-time bias. The recently reported Prostate Cancer Prevention Trial had an overall detection rate that approached the 30%-40% prevalence rates reported in autopsy series in which men died of other causes. However, the prognostic information that can be obtained from prostate cancer found on biopsy is limited. Three-dimensional computer modeling is one technique that allows multiple studies on "immortal" prostates to test methods of biopsy sampling accuracy and to assist in the determination of the disease's severity. Computer modeling can assess detection rates and assesses tumor multifocality and heterogeneity. It can provide a more accurate representation of tumor volume, aiding in therapeutic decision making, and can assess sampling errors of various biopsy methods. It has been shown to be superior to wire-frame technique by immortalizing the original shape and dimensions of the surgically excised prostate gland. Moreover, our 3-dimensional computer modeling system improves upon other systems: It is more than a simple extension of the planimetric technique, and it is able to demarcate clearly the boundaries of Gleason grades just 1 grade apart.

Adenocarcinoma↗

PubMed2003

Molecular characterization of human prostate carcinoma cell lines.

BACKGROUND: This study presents a comprehensive survey and characterization of available prostate carcinoma cell lines, most of which have been widely used but are incompletely characterized. METHODS: A total of 21 cell lines were investigated, including three "classical" (DU 145, LNCaP, and PC-3) and 18 "non-classical" lines (1013L, 22Rv1, ALVA-55, ALVA-101, ARCaP, CWR-R1, DuCaP, DuPro-1, LAPC-4, MDA PCa 1, MDA PCa 2a, MDA PCa 2b, NCI-H660, PC-346C, PC-93, PSK-1, UM-SCP-1, and VCaP). Cytogenetics, DNA profiling, expression of basal, luminal, and neuroendocrine differentiation markers, and mutation analyses of the TP53 and androgen receptor (AR) genes were performed. RESULTS: Based on cytogenetics and DNA profiling analyses, out of the 18 "non-classical" lines, six were confirmed to be unique, eight (in four pairs) were confirmed to be related in origin, and four lines were identified as cross-contaminants. Of this latter group, PC-93 was found to be a derivative of HeLa, whereas DuPro-1, ALVA-55, and ALVA-101 were derivatives of PC-3. The 17 genuine prostate cell lines expressed keratin 8 (K8) and K18. Nine showed AR expression, of which five harbored mutations in the AR gene. Prostate-specific antigen and DD3 were exclusively detected in AR expressing cell lines. Seven lines expressed the basal cell marker K5, three of these lines showed co-expression of AR. CONCLUSIONS: This study defines a collection of 17 genuine prostate carcinoma cell lines. This collection, although small, constitutes a variety of different types and stages of prostate cancer, while it also partly reflects the heterogeneous nature of this malignancy.

Blotting, Western↗

PubMed2003

Laterally directed biopsies detect more clinically threatening prostate cancer: computer simulated results.

BACKGROUND: The purpose of this study was to determine, whether a modified fan-shaped biopsy (MFSB) technique which utilizes six laterally directed biopsies would lead to higher detection rates of clinically threatening prostatic carcinoma than the six random systematic core biopsy (SRSCB) method. METHODS: We reconstructed 3-dimensional solid computer models of 86 autopsy prostates and 40 radical prostatatectomy specimens. Simulations of SRSCB and MFSB were then performed using the same biopsy sites except that the biopsy probe was rotated 45 degrees toward posterolateral peripheral zone for MFSB. When the Gleason sum was less than 7, clinically threatening cancers were defined as having a tumor volume > or =0.25 cc or > or =0.5 cc. RESULTS: When the cut off volume was 0.25 cc, MFSB detected significantly more threatening carcinomas in autopsy prostates than did SRSCB (P < 0.0082). This was also true for the surgical prostates (P < 0.0047) as well as for a sub-group of non-palpable carcinomas (P < 0.0047). When the cut off volume was increased to 0.5 cc, MFSB detected significantly more threatening carcinomas in the radical series (P < 0.0047) and for the non-palpable carcinomas (P < 0.0082), but not in the autopsy series. CONCLUSIONS: The MFSB technique, which utilizes laterally directed biopsies, appears to be an effective approach to improve the detection of clinically threatening prostatic carcinoma.

Adult↗

PubMed2003

Aberrant HOXC expression accompanies the malignant phenotype in human prostate.

Dysregulation of HOX gene expression has been implicated as a factor in malignancies for a number of years. However, no consensus has emerged regarding specific causative genes. Using a degenerate reverse transcription-PCR technique, we show up-regulation of genes from the HOXC cluster in malignant prostate cell lines and lymph node metastases. When relative expression levels of the four HOX clusters were examined, lymph node metastases and cell lines derived from lymph node metastases exhibited very similar patterns, patterns distinct from those in benign cells or malignant cell lines derived from other tumor sites. Specific reverse transcription-PCR for HOXC4, HOXC5, HOXC6, and HOXC8 confirmed overexpression of these genes in malignant cell lines and lymph node metastases. Laser capture microdissection and examination of paired tumor/normal prostate epithelial cells also indicated overexpression of these HOXC genes in primary tumor cells. Our data indicate a possible link between expression of HOXC genes and malignancy in prostate cells. Overexpression of HOXC8 in LNCaP prostate cancer cells suppressed transactivation by androgen receptors. We speculate that HOXC overexpression may predispose tumor cells to androgen independence by necessitating adaptation to diminished androgen signaling.

Androgens↗