Clinical studies of apoptosis and proliferation in breast cancer

Assessment of the sensitivity of 2 H MR spectroscopy measurements of [2,3-2 H2 ]fumarate metabolism for detecting tumor cell death

Imaging the metabolism of [2,3-2 H2 ]fumarate to produce malate can be used to detect tumor cell death post-treatment. Here, we assess the sensitivity of the technique for detecting cell death by lowering the concentration of injected [2,3-2 H2 ]fumarate and by varying the extent of tumor cell death through changes in drug concentration. Mice were implanted subcutaneously with human triple negative breast cancer cells (MDA-MB-231) and injected with 0.1, 0.3, and 0.5 g/kg [2,3-2 H2 ]fumarate before and after treatment with a multivalent TRAlL-R2 agonist (MEDI3039) at 0.1, 0.4, and 0.8 mg/kg. Tumor conversion of [2,3-2 H2 ]fumarate to [2,3-2 H2 ]malate was assessed from a series of 13 spatially localized 2 H MR spectra acquired over 65 min using a pulse-acquire sequence with a 2-ms BIR4 adiabatic excitation pulse. Tumors were then excised and stained for histopathological markers of cell death: cleaved caspase 3 (CC3) and DNA damage (terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL]). The rate of malate production and the malate/fumarate ratio plateaued at tumor fumarate concentrations of 2 mM, which were obtained with injected [2,3-2 H2 ]fumarate concentrations of 0.3 g/kg and above. Tumor malate concentration and the malate/fumarate ratio increased linearly with the extent of cell death determined histologically. At an injected [2,3-2 H2 ]fumarate concentration of 0.3 g/kg, 20% CC3 staining corresponded to a malate concentration of 0.62 mM and a malate/fumarate ratio of 0.21. Extrapolation indicated that there would be no detectable malate at 0% CC3 staining. The use of low and nontoxic fumarate concentrations and the production of [2,3-2 H2 ]malate at concentrations that are within the range that can be detected clinically suggest this technique could translate to the clinic.

Update on Quantitative Imaging for Predicting and Assessing Response in Oncology

Molecular imaging has revolutionized clinical oncology by imaging-specific facets of cancer biology. Through noninvasive measurements of tumor physiology, targeted radiotracers can serve as biomarkers for disease characterization, prognosis, response assessment, and predicting long-term response/survival. In turn, these imaging biomarkers can be utilized to tailor therapeutic regimens to tumor biology. In this article, we review biomarker applications for response assessment and predicting long-term outcomes. ¹⁸F-fluorodeoxyglucose (FDG), a measure of cellular glucose metabolism, is discussed in the context of lymphoma and breast and lung cancer. FDG has gained widespread clinical acceptance and has been integrated into the routine clinical care of several malignancies, most notably lymphoma. The novel radiotracers 16α-¹⁸F-fluoro-17β-estradiol and ¹⁸F-fluorothymidine are reviewed in application to the early prediction of response assessment of breast cancer. Through illustrative examples, we explore current and future applications of molecular imaging biomarkers in the advancement of precision medicine.

Bcl-2 antigen expression in luminal A and triple-negative breast cancer

Biomarkers for the prognosis of breast cancer have been routinely used in clinical practice, including the expression of hormone receptors, Ki-67 and HER-2. More recently, Bcl-2 has been recognized as an important prognostic factor in breast cancer, although controversies persist with respect to the significance of its expression. The aim of the present study was to evaluate Bcl-2 antigen expression in luminal A and triple-negative breast cancer. Sixty women with invasive ductal carcinoma were included in the study and divided into two groups: Group A (luminal A) and Group B (triple-negative), with 30 cases in each group. Immunohistochemistry was performed on tissue sections to evaluate Bcl-2 antigen expression. Fisher's exact test was used to compare the proportions of cases with cells expressing Bcl-2 between the two subtype cancer groups, with statistical significance being established at p < 0.05. The number of cases with cells expressing Bcl-2 in Groups A and B was 26 (86.7%) and 12 (40.0%), respectively (p < 0.0003). In the present study, the expression of the anti-apoptotic protein Bcl-2 was greater in luminal A breast cancer tissue samples compared to triple-negative breast cancer.

Molecular Imaging and Precision Medicine in Breast Cancer

Precision medicine, basing treatment approaches on patient traits and specific molecular features of disease processes, has an important role in the management of patients with breast cancer as targeted therapies continue to improve. PET imaging offers noninvasive information that is complementary to traditional tissue biomarkers, including information about tumor burden, tumor metabolism, receptor status, and proliferation. Several PET agents that image breast cancer receptors can visually demonstrate the extent and heterogeneity of receptor-positive disease and help predict which tumors are likely to respond to targeted treatments. This review presents applications of PET imaging in the targeted treatment of breast cancer.

Development of Companion Diagnostics

The goal of individualized and targeted treatment and precision medicine requires the assessment of potential therapeutic targets to direct treatment selection. The biomarkers used to direct precision medicine, often termed companion diagnostics, for highly targeted drugs have thus far been almost entirely based on in vitro assay of biopsy material. Molecular imaging companion diagnostics offer a number of features complementary to those from in vitro assay, including the ability to measure the heterogeneity of each patient's cancer across the entire disease burden and to measure early changes in response to treatment. We discuss the use of molecular imaging methods as companion diagnostics for cancer therapy with the goal of predicting response to targeted therapy and measuring early (pharmacodynamic) response as an indication of whether the treatment has "hit" the target. We also discuss considerations for probe development for molecular imaging companion diagnostics, including both small-molecule probes and larger molecules such as labeled antibodies and related constructs. We then describe two examples where both predictive and pharmacodynamic molecular imaging markers have been tested in humans: endocrine therapy for breast cancer and human epidermal growth factor receptor type 2-targeted therapy. The review closes with a summary of the items needed to move molecular imaging companion diagnostics from early studies into multicenter trials and into the clinic.

Ursolic Acid Induces Apoptosis of Prostate Cancer Cells via the PI3K/Akt/mTOR Pathway

Ursolic acid (UA), a pentacyclic triterpenoid, is known to exert antitumor activity in breast, lung, liver and colon cancers. Nonetheless, the underlying mechanism of ursolic acid in prostate cancer cells still remains unclear. In the present study, we report the chemotherapeutic effects of ursolic acid as assessed using in vitro and in vivo models. Treatment of human prostate cancer cells (LNCaP and PC-3) with UA inhibited the proliferation and induced apoptosis in both cell lines as characterized by the increased Annexin V-binding. The induction of apoptosis by UA was associated with a decrease in the levels of Bcl-2, Bcl-xl, survivin, and activated caspase-3. Treatment with UA also inhibited the expression of phosphatidylinositol-3-kinase (PI3K), phosphorylation of Akt and mTOR signaling proteins. Further, administration of UA significantly inhibited the growth of LNCaP prostate tumor xenografts in athymic nude mice, which was associated with inhibition of cell proliferation, induction of apoptosis of tumor cells and decreased expression of PI3K downstream factors, such as p-Akt and p-mTOR in tumor xenograft tissues. Our study demonstrates that UA not only inhibits cell growth but also induces apoptosis through modulation of the PI3K/Akt/mTOR pathway in human prostate cancer cells. We suggest that UA may be a new chemotherapeutic candidate against prostate cancer.

5,3'-Dihydroxy-6,7,4'-trimethoxyflavanone exerts its anticancer and antiangiogenesis effects through regulation of the Akt/mTOR signaling pathway in human lung cancer cells

5,3'-Dihydroxy-6,7,4'-trimethoxyflavanone (DHTMF) is one of the constituents of Vitex rotundifolia, a medicinal herb that is used for the treatment of various disorders in China and Korea. In this study we evaluated the antitumor and antiangiogeneic activities of DHTMF. DHTMF significantly suppressed growth and induced apoptosis in lung carcinoma cells in a dose-dependent manner, as indicated by a decrease in Bcl-2 levels and increases in Bax and cleaved caspase-3 levels. In addition, DHTMF treatment significantly reduced the phosphorylation of Akt and mammalian target of rapamycin (mTOR), accompanied by reductions in the protein level of hypoxia-inducible factor (HIF-1α) and vascular endothelial growth factor (VEGF), which are key angiogenic molecules in H522 lung cancer cells. Furthermore DHTMF inhibited VEGF-induced angiogenesis, as indicated by reduced expression of CD34, tube formation and migration in human umbilical vein endothelial cells (HUVECs), as well as reduced neovascularization in an in vivo mouse Matrigel plug assay. DHTMF also inhibited phosphorylation of Akt, mTOR, and p70S6K in HUVECs and lung cancer cells. Taken together, our finding indicated that DHTMF inhibits Akt/mTOR signaling and reduces the expression of HIF-1 α and VEGF in tumor cells, which in turns inhibits endothelial cell-mediated angiogenesis. These results suggest that DHTMF inhibits angiogenesis as well as induces apoptosis via the Akt/mTOR pathway and might elicit pharmacological effects that are useful for treatment of lung cancer.

SB365 inhibits angiogenesis and induces apoptosis of hepatocellular carcinoma through modulation of PI3K/Akt/mTOR signaling pathway

Identification of small molecules that safely inhibit cancer progression is critical for cancer therapeutics. Saponins exhibit cytostatic and cytotoxic activity against various cancer cells, but the mechanism is not well understood. Here, we investigated whether saponin D (designated SB365), an active component isolated from Pulsatilla koreana, could inhibit the progression of hepatocellular carcinoma (HCC) and considered its mechanism. SB365 strongly suppressed the growth of HCC cells in a dose-dependent manner and induced apoptosis by increasing the proportion of sub G1 apoptotic cells from 8% to 21% through induction of expression of Bax and cleaved caspase-3. In addition, SB365 exhibited potent anti-angiogenic activity and decreased the expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor, a key molecule for angiogenesis. Furthermore, SB365 suppressed the tube formation and migration of HUVEC, as well as in vivo neovascularization in a mouse Matrigel plug assay. In vivo study showed that SB365 significantly inhibited tumor growth in an HCC xenograft model, inducing apoptosis by increasing the expression of the cleaved caspase-3 and DNA fragmentation. The expressions of vascular endothelial growth factor and CD34 in the tumor tissue were decreased by SB365 treatment. In examining its mechanism, SB365 was found to effectively suppress the phosphorylation of PI3K downstream factors, such as Akt, mTOR and p70S6K both in vitro and in vivo. Our study demonstrates that SB365 not only induces apoptosis but also inhibits cell growth and angiogenesis through modulation of the PI3K/Akt/mTOR pathway in human HCC. We suggest that SB365 may be a new chemotherapeutic candidate against HCC.

Expression of Ki-67 and Bcl-2 biomarkers in normal breast tissue from women of reproductive age treated with raloxifene

OBJECTIVE

To evaluate the effect of raloxifene on antigen expression of Ki-67 and Bcl-2 in normal breast tissue.

MATERIALS AND METHODS

A randomized, double-blind study was conducted with 40 premenopausal women aged 18-40 years who had been diagnosed with fibroadenoma of the breast. The patients were divided into two groups: Group A (placebo, n = 20), and Group B (raloxifene 60 mg, n = 20).The medication was taken for 22 days initiating from the first day of the menstrual cycle. An excisional biopsy was performed on the 23rd day. At the time of biopsy, a sample of normal breast tissue was collected to evaluate protein expression of Ki-67 and Bcl-2. The Student's t test and Chi-square test were used for statistical data analysis and the significance level was established at 5%.

RESULTS

The mean percentage of nuclei stained for Ki-67 was 22.16 ± 1.91 (p < 0.001) and 2.161 ± 0.181 in the control group and the raloxifene group. The expression of Bcl-2 was similar in both groups (p = 0.8888).

CONCLUSIONS

Raloxifene treatment significantly reduced antigen expression of Ki-67, but failed to have any significant results on the Bcl-2 expression. Further studies are warranted to evaluate the mechanism of raloxifene on apoptosis in normal breast tissue.

Deltonin, a steroidal saponin, inhibits colon cancer cell growth in vitro and tumor growth in vivo via induction of apoptosis and antiangiogenesis

Deltonin, a steroidal saponin, isolated from Dioscorea zingiberensis Wright (DZW), has shown high-cytotoxic activity in cancer cells. However, its mechanisms and in vivo anti-cancer effects remain unknown. In the present study, we evaluated the effects and explored the anti-tumor mechanisms of deltonin on a panel of colon cancer cell lines and in a mouse model of murine colon cancer C26. Deltonin had more cytotoxic effect on C26 cells than 5-fluorouracil had, promoting dramatic G2-M phase arrest and apoptosis in C26 cells in a concentration-dependent manner; oral administration of deltonin significantly inhibited the tumor growth and prolonged survival of the tumor bearing mice. The deltonin treatment caused a noticeable apoptosis in tumor tissue, which associated with increased levels of Bax, activated caspase-3, caspase-9, and cleaved poly (ADPribose) polymerase, decreased pro-caspase-8, pro-caspase-9, Bcl-2 expression levels and extracellular signal-regulated kinase-1/2 activity; and dose-dependently inhibit angiogenesis. In conclusion, the findings in this study demonstrated that deltonin is an effective natural agent for cancer therapy, which may be mediated, in part, by induction of apoptosis, as well as involve mitogen-activated protein kinase pathways, and inhibition of angiogenesis.

Opposing actions of the progesterone metabolites, 5alpha-dihydroprogesterone (5alphaP) and 3alpha-dihydroprogesterone (3alphaHP) on mitosis, apoptosis, and expression of Bcl-2, Bax and p21 in human breast cell lines

Previous studies have shown that breast tissues and breast cell lines convert progesterone (P) to 5alpha-dihydroprogesterone (5alphaP) and 3alpha-dihydroprogesterone (3alphaHP) and that 3alphaHP suppresses, whereas 5alphaP promotes, cell proliferation and detachment. The objectives of the current studies were to determine if the 5alphaP- and 3alphaHP-induced changes in cell numbers are due to altered rates of mitosis and/or apoptosis, and if 3alphaHP and 5alphaP act on tumorigenic and non-tumorigenic cells, regardless of estrogen (E) and P receptor status. The studies were conducted on tumorigenic (MCF-7, MDA-MB-231, T47D) and non-tumorigenic (MCF-10A) human breast cell lines, employing several methods to assess the effects of the hormones on cell proliferation, mitosis, apoptosis and expression of Bcl-2, Bax and p21. In all four cell lines, 5alphaP increased, whereas 3alphaHP decreased cell numbers, [(3)H]thymidine uptake and mitotic index. Apoptosis was stimulated by 3alphaHP and suppressed by 5alphaP. 5alphaP resulted in increases in Bcl-2/Bax ratio, indicating decreased apoptosis; 3alphaHP resulted in decreases in Bcl-2/Bax ratio, indicating increased apoptosis. The effects of either 3alphaHP or 5alphaP on cell numbers, [(3)H]thymidine uptake, mitosis, apoptosis, and Bcl-2/Bax ratio, were abrogated when cells were treated simultaneously with both hormones. The expression of p21 was increased by 3alphaHP, and was unaffected by 5alphaP. The results provide the first evidence that 5alphaP stimulates mitosis and suppresses apoptosis, whereas 3alphaHP inhibits mitosis and stimulates apoptosis. The opposing effects of 5alphaP and 3alphaHP were observed in all four breast cell lines examined and the data suggest that all breast cancers (estrogen-responsive and unresponsive) might be suppressed by blocking 5alphaP formation and/or increasing 3alphaHP. The findings further support the hypothesis that progesterone metabolites are key regulatory hormones and that changes in their relative concentrations in the breast microenvironment determine whether breast tissues remain normal or become cancerous.

Chloroquine inhibits colon cancer cell growth in vitro and tumor growth in vivo via induction of apoptosis

The present study was to investigate the anticancer effect of chloroquine on proliferation of mouse colon cancer cell line CT26 in vivo and in vitro and the possible mechanism. We found that chloroquine inhibited CT26 proliferation by concentration- and time-dependent manner. This effect was associated with apoptosis induction and decreased level of phosphorylated p42/44 mitogen-activated protein kinase and phosphorylated Akt. The in vivo study showed chloroquine-reduced tumor volume and prolonged survival time in CT26-bearing mice. These observations indicated chloroquine could inhibit CT26 proliferation by inducing apoptosis both in vitro and in vivo, providing its chemotherapeutic potential of human cancers.

A pilot study to assess the feasibility of evaluation of markers of response to chemotherapy at one day & 21 days after first cycle of chemotherapy in carcinoma of breast: a prospective non-randomized observational study

BACKGROUND

Interest in translational studies aimed at investigating biologic markers in predicting response to primary chemotherapy (PCT) in breast cancer has progressively increased. We conducted a pilot study to evaluate feasibility of evaluating biomarkers of response to PCT at one & 21 days after first cycle.

METHODS

Adult, non-pregnant, non-lactating women with histologically confirmed infiltrating duct carcinoma underwent serial core biopsies after first cycle of PCT and these were scored for Ki-67, Bcl-2 and Caspase-3 using immunohistochemistry.

RESULTS

We recruited 30 patients with a mean age of 51 years. We were successful 95.6% times in performing a core biopsy and of these 84.6% had adequate tissue in the cores harvested. After a mean of 4 cycles of PCT, 26 patients underwent surgery and good response was noted in 9 patients (30%) using Miller-Payne criteria. There was a trend noted in all markers, which appeared different in those with good response and poor response. Good responders had significantly higher Ki-67 and significantly lower Bcl-2 at baseline and a significant decrease in Ki-67 and Caspase-3 at 21 days after the first chemotherapy.

CONCLUSION

We report a detectable change in biomarkers as early as 24-48 hours after the first chemotherapy along with a definite trend in change that can possibly be used to predict response to chemotherapy in an individual patient. The statistical significance and clinical utility of such changes needs to be evaluated and confirmed in larger trials.

Lymphatic chemotherapy induces apoptosis in lymph node metastases in a rabbit breast carcinoma model

The purpose of the study was to evaluate the potential of lymphatic chemotherapy in inducing apoptosis in axillary lymph node metastases in a rabbit breast cancer model. A total of 30 female New Zealand rabbits with mammary implantation of VX2 carcinomas were divided into three groups randomly, with ten in each. Treatment was carried out once axillary lymph node reached 5 mm in the maximum diameter. Group A received a subcutaneous injection of liposomal adriamycin (LADR) adjacent to the breast tumor. Group B received free adriamycin (FADR) administered into the auricular vein. Group C received a sham treatment. The dose of adriamycin in each administration was 1 mg/kg in groups A and B. Treatment was repeated every 48 h. Axillary lymph nodes were dissected out 48 h after the third treatment. The nodal sizes before and after the treatment were measured. The therapeutic effect was evaluated in terms of the node volume ratio and apoptotic index (AI) of metastatic cells in nodes identified with TUNEL technique. The significance of difference was determined with one-way ANOVA followed by the Fischer LSD test. Compared to group C, the enlargement of lymph nodes was sufficiently slowed down in both groups A and B, and group A showed a further strong inhibitory effect than group B (P = 0.002). Apparent VX2 cell apoptosis was detected in the lymph nodes of groups A and B. The average AI in group B (15.31%) was significantly higher than in group C (5.16%). The highest AI was found in animals of group A (21.73%), with a further significant difference from group B (P = 0.000). These data suggest that lymphatic chemotherapy appears to be a promising method to induce apoptosis in lymph node metastases

Estudo da expressão citofotométrica do marcador tumoral Caspase-3 no adenocarcinoma de cólon

RACIONAL: O adenocarcinoma de cólon é a segunda causa mais comum de morte por câncer em homens e mulheres, sendo responsável por mais de cinco milhões de mortes por ano. No momento do diagnóstico apenas 70% dos tumores são ressecáveis, 75% são curáveis e 25% poderão ter recorrência da doença. A apoptose é uma das responsáveis pelo equilíbrio homeostático entre as células. Durante o desenvolvimento do processo de degeneração maligna celular o desequilíbrio na apoptose é considerado um dos principais marcos neoplásicos. A caspase-3 é uma das mais importantes moléculas na apoptose, sendo sua efetora principal. Sua expressão e prognóstico têm sido relatados em vários estudos e revisões com seu papel valorizado desde o surgimento do pólipo até a sua transformação maligna, com a taxa de apoptose diminuindo progressivamente. OBJETIVOS: Avaliar a expressão citofotométrica computadorizada do marcador Caspase-3 no adenocarcinoma de cólon; avaliá-lo nas fases evolutivas na classificação modificada de Dukes e comparar sua expressão nos tumores do lado direito e esquerdo do cólon. MÉTODOS: Utilizaram-se 19 casos de câncer recuperados de blocos de parafina confirmados por hematoxilina-eosina e submetidos à técnica imunoistoquímica da estreptavidina-biotina com anticorpo policlonal anti-caspase-3. Após este processo as lâminas marcadas foram submetidas à leitura pelo sistema SAMBA com o software IMUNNO 4.00. Foram analisados três índices: marcagem (Label index), heterogeneidade e densidade óptica. Utilizaram-se a marcagem individual, avaliação da expressão do marcador e grupos definidos de tumores com classificação Dukes e pelo lado do tumor. RESULTADOS: A média do índice de marcagem da caspase-3 foi de 85,24 e da densidade óptica de 39,55. Na classificação Dukes de 12 tipos B tiveram índice de marcagem de 86,20 e a densidade óptica de 37,72 e para os 7 tipos C a área de marcagem foi de 85,66 e a densidade óptica foi de 42,71 não sendo possível identificar diferença em relação a classificação de Dukes. Quanto ao lado do tumor os 11 tumores à esquerda tiveram índice de marcagem de 86,65 e densidade óptica de 43,29 e os 8 à direita tíndice de marcagem de 83,29 e densidade óptica de 39,44 não sendo possível observar diferença estatística significante. CONCLUSÕES: A caspase-3 possui alta expressão individual revelando-se marcador de boa utilidade no estudo do adenocarcinoma de cólon e da fase pró-apoptóica da sua tumorigênese pelo seu alto grau de índice de marcagem e densidade óptica. Em relação à classificação Dukes não houve diferença entre os tipos B e C, como também em relação ao lado direito e esquerdo do cólon.

Modulation of estrogen receptor alpha protein level and survival function by DBC-1

Acquired resistance to endocrine therapy represents a major clinical obstacle to the successful management of estrogen-dependent breast cancers expressing estrogen receptor alpha (ERalpha). Because a switch from ligand-dependent to ligand-independent activation of ERalpha-regulated breast cancer cell growth and survival may define a path to endocrine resistance, enhanced mechanistic insight concerning the ligand-independent fate and function of ERalpha, including a more complete inventory of its ligand-independent cofactors, could identify novel markers of endocrine resistance and possible targets for therapeutic intervention in breast cancer. Here, we identify the deleted in breast cancer 1 gene product DBC-1 (KIAA1967) to be a principal determinant of unliganded ERalpha expression and survival function in human breast cancer cells. The DBC-1 amino terminus binds directly to the ERalpha hormone-binding domain both in vitro and in vivo in a strict ligand-independent manner. Furthermore, like estrogen, the antiestrogens tamoxifen and ICI 182,780 (7alpha,17beta-[9-[(4,4,5,5,5-pentafluoropentyl)sulfinyl]nonyl]estra-1,3,5(10)-triene-3,17-diol) disrupt the DBC-1/ERalpha interaction, thus revealing the DBC-1/ERalpha interface to be a heretofore-unrecognized target of endocrine compounds commonly used in hormonal therapy. Notably, RNA interference-mediated DBC-1 depletion reduces the steady-state level of unliganded but not liganded ERalpha protein, suggesting that DBC-1 may stabilize unliganded ERalpha by virtue of their direct association. Finally, DBC-1 depletion promotes hormone-independent apoptosis of ERalpha-positive, but not ERalpha-negative, breast cancer cells in a manner reversible by endocrine agents that disrupt the DBC-1/ERalpha interaction. Collectively, these findings establish a principal biological function for DBC-1 in the modulation of ERalpha expression and hormone-independent breast cancer cell survival.

Imaging early changes in proliferation at 1 week post chemotherapy: a pilot study in breast cancer patients with 3′-deoxy-3′-[18F]fluorothymidine positron emission tomography

PURPOSE

3'-deoxy-3'-[18F]fluorothymidine positron emission tomography ([18F]FLT-PET) has been developed for imaging cell proliferation and findings correlate strongly with the Ki-67 labelling index in breast cancer. The aims of this pilot study were to define objective criteria for [18F]FLT response and to examine whether [18F]FLT-PET can be used to quantify early response of breast cancer to chemotherapy.

METHODS

Seventeen discrete lesions in 13 patients with stage II-IV breast cancer were scanned prior to and at 1 week after treatment with combination 5-fluorouracil, epirubicin and cyclophosphamide (FEC) chemotherapy. The uptake at 90 min (SUV90) and irreversible trapping (Ki) of [18F]FLT were calculated for each tumour. The reproducibility of [18F]FLT-PET was determined in nine discrete lesions from eight patients who were scanned twice before chemotherapy. Clinical response was assessed at 60 days after commencing FEC.

RESULTS

All tumours showed [18F]FLT uptake and this was reproducible in serial measurements (SD of mean % difference=10.5% and 15.1%, for SUV90 and Ki, respectively; test-retest correlation coefficient>or=0.97). Six patients had a significant clinical response (complete or partial) at day 60; these patients also had a significant reduction in [18F]FLT uptake at 1 week. Decreases in Ki and SUV90 at 1 week discriminated between clinical response and stable disease (p=0.022 for both parameters). In three patients with multiple lesions there was a mixed [18F]FLT response in primary tumours and metastases. [18F]FLT response generally preceded tumour size changes.

CONCLUSION

[18F]FLT-PET can detect changes in breast cancer proliferation at 1 week after FEC chemotherapy.

Survivin is an independent predictor of short-term survival in poor prognostic breast cancer patients

Established clinico–pathological factors can place patients with breast cancer into good and poor prognostic categories, but even within these groups behaviour and response to treatment can differ. This study examined the value of cell cycle and apoptotic regulatory proteins in predicting behaviour in a poor prognostic group. A total of 165 patients, all of whom had died of breast cancer with duration of survival 12–127 months, median 38 months, were examined using immunohistochemistry for proliferation, apoptosis, p53, phosphorylated p53, p21, checkpoint kinase 2 (Chk2), bcl-2, bax, survivin and XIAP. All had received chemotherapy and/or hormonal therapy and were predominantly T2, node positive, grade III with only half oestrogen-receptor (ER) positive. High proliferation, phosphorylated p53, Chk2 and survivin expression correlated with grade III and lack of ER, whereas low proliferation, p21 and bcl-2 related to better grade and presence of ER. On univariate analysis grade, proliferation, phosphorylated p53, bcl-2, ER and survivin related to duration of survival. In multivariate analysis, grade (P=0.001) and survivin (P=0.005) were independent prognostic factors, grade III and presence of survivin relating to shorter survival. The latter was particularly for those patients receiving neoadjuvant therapy and adjuvant chemo- and hormonal therapy. The presence of the inhibitor of apoptosis protein survivin is a highly significant independent predictor of shorter duration of survival of patients with poor prognostic features, and merits investigation as a marker in other prognostic groups.

Hormonal therapy for postmenopausal breast cancer: the science of sequencing

Oestrogens play important roles in the natural history of breast cancer. Consequently, therapies have been developed to reduce oestrogen levels or to block signalling through oestrogen receptors (ER). These therapies include tamoxifen, selective oestrogen receptor modulators (SERMs), aromatase inhibitors (AIs) and selective oestrogen receptor downregulators (SERDs). All have proven clinical efficacy in postmenopausal women with ER-positive breast cancer and can be effective in the neoadjuvant and adjuvant settings, and in the management of advanced disease. This range of endocrine therapies offers the opportunity for prolonging benefit from treatment and delaying tumour recurrence/progression by combining the different classes of drugs or by using them sequentially. Evaluation of the potential clinical benefits of concomitant or sequential endocrine therapies should be based on considerations of efficacy and safety profiles, mechanisms of action/resistance and effects on tumour biology. Evidence from preclinical models and from randomized clinical trials in patients with postmenopausal breast cancer suggests that concomitant endocrine therapies are no more effective than AIs alone. However, using AIs either as initial therapy or sequentially after tamoxifen appears to produce more benefits beyond the use of tamoxifen alone.Currently, there are no proven algorithms for the planned, sequential use of the full range of endocrine therapies, particularly for the majority of patients who present with early breast cancer. Prospective, randomized clinical trials are needed to determine the best use of therapies in particular settings, taking into account the spectrum of molecular phenotypes in different tumours.

Effect of 5-fluorouracil, Optison and ultrasound on MCF-7 cell viability

The aim of this study was to analyze cell viability and expression of apoptotic-related signaling proteins in MCF-7 breast cancer cells induced by combinations of ultrasound, the anticancer drug 5-fluorouracil (5-FU) and the ultrasound contrast agent Optison. MCF-7 cells were treated with 5-FU and sonicated at the frequency of 3.0 MHz and intensity of 3.0 W/cm2 for 1 min in the presence of Optison. The cells were analyzed for lactate dehydrogenase (LDH) release (a measure of cytotoxicity) and cell proliferation (by MTT assays). The LDH/MTT ratio was used for assessment of cell death. Expression of the apoptotic-related proteins, Bax and p27kip1, as well as phosphorylated forms of ERK and Akt proteins was assessed by Western blot analysis. We demonstrate that, immediately after treatment, cell death was most dependent on Optison; however, 24 h after treatment, cell death was more dependent on 5-FU. Ultrasound duty cycle increased cell death associated with either Optison or 5-FU. Furthermore, we show that treatment with 5-FU and ultrasound increased the levels of the Bax and p27kip1 proteins, but the addition of Optison appears to suppress apoptotic protein expression.

In vivo model for research of breast cancer biomarkers

The preoperative (neoadjuvant) setting of breast cancer treatment is an optimal in vivo model by which to allow the characterization of biomarker expression pattern with the tumor remaining in situ throughout treatment as an in vivo measure of response to particular therapy. Elucidating surrogate molecular or cellular markers of tumor response to therapy, may provide biological insight into both, the mechanism of tumor growth dynamics and drug sensitivity/resistance. Owing to the knowledge that many drugs are effective on actively proliferating cells and more intriguingly, that many anticancer agents with differing modes of action achieve cytotoxic effects by inducing apoptosis, has lead to a reappraisal of traditional views of tumor response/resistance to cytotoxic drugs in vivo. Accordingly, this review article will focus on discussing apoptosis phenomena and the p53 and bcl-2 protein as its regulators of principal impor?tance; a cell proliferation determined by the Ki-67 expression, as the major counterbalancing process to apoptosis is also considered. This paper reviews the rationale for the use of these proteins as indices of tumor response to therapy, as well as the published literature regarding their clinical relevance. So far, no firm conclusions can be made concerning their predictive utility. .

Intrinsic mechanism of estradiol-induced apoptosis in breast cancer cells resistant to estrogen deprivation

BACKGROUND

We previously developed an estrogen receptor (ER)-positive breast cancer cell line (MCF-7:5C) that is resistant to long-term estrogen deprivation and undergoes rapid and complete apoptosis in the presence of physiologic concentrations of 17beta-estradiol. Here, we investigated the role of the mitochondrial apoptotic pathway in this process.

METHODS

Apoptosis in MCF-7:5C cells treated with estradiol, fulvestrant, or vehicle (control) was investigated by annexin V-propidium iodide double staining and 4',6-diamidino-2-phenylindole (DAPI) staining. Apoptosis was also analyzed in MCF-7:5C cells transiently transfected with small interfering RNAs (siRNAs) to apoptotic pathway components. Expression of apoptotic pathway intermediates was measured by western blot analysis. Mitochondrial transmembrane potential (psim) was determined by rhodamine-123 retention assay. Mitochondrial pathway activity was determined by cytochrome c release and cleavage of poly(ADP-ribose) polymerase (PARP) protein. Tumorigenesis was studied in ovariectomized athymic mice that were injected with MCF-7:5C cells. Differences between the treatment groups and control group were determined by two-sample t test or one-factor analysis of variance. All statistical tests were two-sided.

RESULTS

MCF-7:5C cells treated with estradiol underwent apoptosis and showed increased expression of proapoptotic proteins, decreased psim, enhanced cytochrome c release, and PARP cleavage compared with cells treated with fulvestrant or vehicle. Blockade of Bax, Bim, and p53 mRNA expression by siRNA reduced estradiol-induced apoptosis relative to control by 76% [95% confidence interval (CI) = 73% to 79%, P < .001], 85% [95% CI = 90% to 80%, P < .001], and 40% [95% CI = 45% to 35%, P < .001], respectively, whereas blockade of FasL by siRNA had no effect. Estradiol caused complete regression of MCF-7:5C tumors in vivo.

CONCLUSION

The mitochondrial pathway of apoptosis plays a critical role in estradiol-induced apoptosis in long-term estrogen-deprived breast cancer cells. Physiologic concentrations of estradiol could potentially be used to induce apoptosis and tumor regression in tumors that have developed resistance to aromatase inhibitors.

Maintenance Therapy to Suppress Micrometastasis: The New Challenge for Adjuvant Cancer Treatment

The palliative efficacy of cytotoxic drugs is routinely assessed using tumor shrinkage (response) rates shown in clinical trials. Although adjuvant drug therapy has a goal distinct from that of palliative therapy (i.e., to prolong survival by inhibiting progression of micrometastatic disease), it is widely assumed that the adjuvant efficacy of a drug will parallel its response rate ("activity") in advanced stages of the disease. Reconsideration of this assumption seems timely in view of recent developments: the realization that many predictors of short-term tumor response correlate inversely with long-term survival outcomes; the characterization of tumor progression as a discontinuous process that may include dormant phases; the understanding that micrometastasis is therapeutically suppressible by a variety of mechanisms including direct tumor cell kill, cytotoxic disruption of paracrine growth signals from normal tissues, and targeted inhibition of prometastatic pathways; the recognition that tumor dormancy not only blocks the antimetastatic efficacy of cytotoxic drugs but also represents a therapeutic end point for metastasis-suppressive noncytotoxic drugs such as hormone inhibitors; and the insight that optimal adjuvant drug therapy is likely to include both induction and maintenance components. The traditional view of cytoreductive response as a prerequisite for adjuvant drug efficacy thus merits reappraisal, with a view to accelerating incorporation of novel noncytotoxic maintenance therapies into controlled studies.

HER2/neu, p53, Ki67, and hormone receptors do not change during neoadjuvant chemotherapy in breast cancer

The selection of a systemic breast cancer therapy is based on the expression pattern of immunohistochemical prognostic markers. In our study we sought to determine whether neoadjuvant chemotherapy may alter these expression patterns within the tumors. Our hypothesis was that the expression of the immunohistochemical prognostic markers does not differ between tissue specimens before and after neoadjuvant chemotherapy. We determined the protein expression levels of estrogen receptor, progesterone receptor, Ki67, p53 and HER2/neu in the core biopsy and the resected tumor sample from 25 patients receiving neoadjuvant chemotherapy. As a control group, we analyzed sample pairs from 30 patients who did not receive neoadjuvant chemotherapy. Additionally, we determined the relative HER2/neu gene copy number by FISH and/or real-time PCR. There were no significant differences in the changes in expression patterns from the core biopsy to the treated resected tumor between those who had received neoadjuvant chemotherapy and the control group. We suggest that it is sufficient to analyze the prognostic factors from either the core biopsy prior to chemotherapy or the treated tumor sample instead of investigating both samples. This would markedly reduce the costs.

Prognostic value of proliferation in invasive breast cancer: a review

Breast cancer is the leading cause of death among solid tumours in women, and its incidence is increasing in the West. Adjuvant chemotherapy and hormonal treatment improve survival but have potentially serious side effects, and are costly. Because adjuvant treatment should be given to high risk patients only, and traditional prognostic factors (lymph node status, tumour size) are insufficiently accurate, better predictors of high risk and treatment response are needed. Invasive breast cancer metastasises haematogenously very early on, so many breast cancer prognosticators are directly or indirectly related to proliferation. Although studies evaluating the role of individual proliferation regulating genes have greatly increased our knowledge of this complex process, the functional end result-cells dividing-has remained the most important prognostic factor. This article reviews the prognostic value of different proliferation assays in invasive breast cancer, and concludes that increased proliferation correlates strongly with poor prognosis, irrespective of the methodology used. Mitosis counting provides the most reproducible and independent prognostic value, and Ki67/MIB1 labelling and cyclin A index are promising alternatives that need methodological fine tuning.

Apoptosis-detecting radioligands: current state of the art and future perspectives

This review provides a critical and thorough overview of the radiopharmaceutical development and in vivo evaluation of all apoptosis-detecting radioligands that have emerged so far, along with their possible applications in nuclear medicine. The following SPECT and PET radioligands are discussed: all forms of halogenated Annexin V (i.e. (123)I-labelled, (124)I-labelled, (125)I-labelled, (18)F-labelled), (99m)Tc/(94m)Tc-labelled Annexin V derivatives using different chelators and co-ligands (i.e. BTAP, Hynic, iminothiolane, MAG(3), EDDA, EC, tricarbonyl, SDH) or direct (99m)Tc-labelling, (99m)Tc-labelled Annexin V mutants and (99m)Tc/(18)F-radiopeptide constructs (i.e. AFIM molecules), (111)In-DTPA-PEG-Annexin V, (11)C-Annexin V and (64)Cu-, (67)Ga- and (68)Ga-DOTA-Annexin V. In addition, the potential role and clinical relevance of anti-PS monoclonal antibodies and other alternative apoptosis markers are reviewed, including: anti-Annexin V monoclonal antibodies, radiolabelled caspase inhibitors and substrates and mitochondrial membrane permeability targeting radioligands. Nevertheless, major emphasis is placed on the group of Annexin V-based radioligands, in particular (99m)Tc-Hynic-Annexin V, since this molecule is by far the most extensively investigated and best-characterised apoptosis marker at present. Furthermore, the newly emerging imaging modalities for in vivo detection of programmed cell death, such as MRI, MRS, optical, bioluminescent and ultrasound imaging, are briefly described. Finally, some future perspectives are presented with the aim of promoting the development of potential new strategies in pursuit of the ideal cell death-detecting radioligand.

Influence of Neoadjuvant Therapy with Epirubicin and Docetaxel on the Expression of HER2/neu in Patients with Breast Cancer

BACKGROUND

In primary breast cancer, the expression levels of biological markers relevant to the progression of the disease may be altered by administration of anticancer drugs. Since neoadjuvant chemotherapy with epirubicin and docetaxel is increasingly used in advanced breast cancer, our purpose was to assess the influence of this neoadjuvant chemotherapy on the expression of the growth factor receptor HER2/neu.

PATIENTS AND METHODS

We investigated changes of HER2/neu status by immunohistochemistry (IHC) and applied additional fluorescence in situ hybridization (FISH) in patients with potential modulation of HER2/neu status after administration of neoadjuvant chemotherapy with docetaxel and epirubicin in 97 breast cancer patients. The influence of neoadjuvant chemotherapy on HER2/neu expression was calculated by correlation of HER2/neu status before and after chemotherapy.

RESULTS

The accuracy of HER2/neu assessment before and after neoadjuvant chemotherapy by IHC combined with FISH analysis in selected cases was 100%. The evaluation of HER2/neu status in these patients by IHC alone yielded accuracy of 93%. Neoadjuvant chemotherapy with epirubicin and docetaxel caused no significant modulation of HER2/neu status (p = 0.66).

DISCUSSION

The administration of epirubicin and docetaxel in the neoadjuvant setting is not associated with significant changes of HER2/neu status in primary breast cancer. As a consequence, drug resistance or sensitivity is not induced by modulation of HER2/neu expression. Moreover, the time of assessment of the HER2/neu status is not a critical factor under neoadjuvant therapy with epirubicin and docetaxel.

A subset of breast invasive ductal carcinoma with distinctive cytomorphology, aggressive clinical behavior, and unique immunologic profiles

BACKGROUND

Invasive ductal carcinoma of the breast is a heterogeneous collection of divergent types of carcinomas. Some subtypes have been characterized by histologic observations. This study describes a distinctive subset recognized through cytomorphologic examination of breast carcinoma specimens obtained by fine-needle aspiration biopsies (FNAB). Identification of this subset is established further by analyses of its clinical and immunologic characteristics.

METHODS

One hundred patients underwent FNAB and were diagnosed with breast ductal carcinoma. These diagnoses were followed by surgical resections and histologic evaluation of tumors. Immunohistochemical analyses of estrogen receptor, progesterone receptor, Her2/neu, p53 protein, and Ki-67 were performed. Patient's age, race, and family history of breast carcinoma were obtained. The objective of the study is to identify a cytomorphologically distinctive, clinically relevant, subset of breast carcinomas.

RESULTS

A subset carcinoma was recognized by cytomorphologic examination of Pap-stained FNAB slides. This subset consisted of seven patients with a median age of 37 years. At the time of surgical resection, all patients had axillary lymph node metastases. Six of seven patients had distant metastases. Immunohistochemical studies revealed that all tumors are positive for p53 protein and negative for estrogen and progesterone receptors.

CONCLUSION

This study presented a unique subset of breast ductal carcinomas that involved young patients and had aggressive growth behavior. These tumors expressed p53 protein but not estrogen and progesterone receptors.

Tamoxifen resistance in breast cancer: elucidating mechanisms

Tamoxifen has been used for the systemic treatment of patients with breast cancer for nearly three decades. Treatment success is primarily dependent on the presence of the estrogen receptor (ER) in the breast carcinoma. While about half of patients with advanced ER-positive disease immediately fail to respond to tamoxifen, in the responding patients the disease ultimately progresses to a resistant phenotype. The possible causes for intrinsic and acquired resistance have been attributed to the pharmacology of tamoxifen, alterations in the structure and function of the ER, the interactions with the tumour environment and genetic alterations in the tumour cells. So far no prominent mechanism leading to resistance has been identified. The recent results of a functional screen for breast cancer antiestrogen resis- tance (BCAR) genes responsible for development of tamoxifen resistance in human breast cancer cells are reviewed. Individual BCAR genes can transform estrogen-dependent breast cancer cells into estrogen-independent and tamoxifen-resistant cells in vitro. Furthermore, high levels of BCAR1/pl30Cas protein in ER-positive primary breast tumours are associated with intrinsic resistance to tamoxifen treatment. These results indicate a prominent role for alternative growth control pathways independent of ER signalling in intrinsic tamoxifen resistance of ER-positive breast carcinomas. Deciphering the differentiation characteristics of normal and malignant breast epithelial cells with respect to proliferation control and regulation of cell death (apoptosis) is essential for understanding therapy response and development of resistance of breast carcinoma.

Activation of transcription by estrogen receptor alpha and beta is cell type- and promoter-dependent

Tamoxifen acts as a strong estrogen antagonist in human breast but as an estrogen agonist in the uterus. The action of tamoxifen is mediated through estrogen receptors (ERalpha and ERbeta), which bind to a variety of responsive elements, to activate transcription. To examine the role of these varied elements in the response to antiestrogens, we studied the activation of a panel of differing promoters, by these compounds, in human breast, bone, and endometrial derived cell lines. No agonistic activity was observed in breast cells, whereas all antiestrogens, particularly tamoxifen, exhibited agonistic effects in uterine cell lines. All antiestrogens studied were agonistic in co-transfections of a collagenase reporter gene and ERbeta, but tamoxifen alone was agonistic with ERalpha in (uterine) HEC-1-A cells. The ERalpha mediated, agonism of tamoxifen was not observed in primary cultures of human uterine stromal cells, whereas the ERbeta-mediated agonism of all selective estrogen receptor modulators was present. This suggests that the two receptors operate by distinct pathways and that the response of cells to antiestrogens is dependent on the ER subtypes expressed.