In vitro characterization and engraftment of adipocytes derived from human induced pluripotent stem cells and embryonic stem cells

Human induced pluripotent stem (iPS) and embryonic stem (ES) cells can differentiate into a variety of cell types. We reported on adipogenic potential of human iPS and ES cells in vitro. In the present study, we investigate the survival and maintenance of adipocytes differentiated in vitro from human iPS and ES cells after transplantation. Following adipogenic induction in vitro, the differentiated cells exhibited functional properties of adipocytes such as lipid storage, lipolysis, and insulin responsiveness. Subsequently, Matrigel containing the differentiated human iPS and ES cells was transplanted into the subcutaneous tissue of nude mice. After 1-4 weeks, the cells with adipocyte-like features were observed in transplanted Matrigel by histological analysis. The human origin of the cells, their lipid accumulation, and gene expression of adipocyte markers in transplanted cells were then confirmed, suggesting the presence of adipocytes in transplanted Matrigel. When the relative areas of these cells were calculated by dividing the adipocyte areas by the total Matrigel areas, we found that they peaked at 2 weeks after transplantation, and that the adipocytes persisted at 4 weeks. The present study demonstrates that human iPS and ES cells can differentiate into adipocytes with functional properties and that adipocytes derived from human iPS and ES cells can survive and maintain the differentiated properties of adipocytes for at least 4 weeks after transplantation. Adipocytes derived from human iPS and ES cells thus have the potential to open new avenues for stem cell-based research into metabolic diseases and future therapeutic applications.

Partial epilepsy and developmental delay in infant with ring chromosome 14

Ring chromosome 14 (r14) is clinically characterized by early-onset epilepsy, mental retardation, delayed speech, microcephaly, extremely mild facial dysmorphisms and ophthalmologic abnormalities. We report a case presenting with partial seizures and delayed development in infancy in which r14 was diagnosed based on chromosomal analysis. The patient was a girl with a normal family and delivery history. Afebrile generalized convulsions developed at age 9 months, and phenobarbital was started, but was changed to zonisamide due to impaired liver function. Chromosome analysis led to a diagnosis of 46, XX, r(14) (p11.2q32.3). At age 5 years, while under treatment with zonisamide and clobazam, epilepsy was characterized by multiple daily episodes of complex partial seizures. Although there are no consistent brain MRI or electroencephalogram findings, experienced pediatric neurologists can make a diagnosis based on facial dysmorphisms. When refractory epilepsy is encountered in infancy with developmental delay of unknown cause, chromosome analysis should be performed.

Abstract P4-15-05: Long-term outcome of breast cancer patients treated with radiofrequency ablation

Background: Radiofrequency ablation (RFA) is considered to be the most promising non-surgical ablation technique for the treatment of small breast cancer. In feasibility studies, the ablated tumor was surgically removed after RFA, and the tumor cell viability were assessed by histological and/or immunohistological examinations. However, these assessments of tumor viability do not take the place of long-term follow-up in patients treated with RFA alone, because they do not allow for them to be followed up for recurrence after RFA, or to determine if there were any undesirable complications of this procedure. At present, few data are available regarding long-term follow-up of patients treated with this modality.

Methods: Since 2005, we have performed RFA and sentinel lymph node (SLN) biopsy in 19 cases with invasive breast cancer less than 2.0 cm in greatest diameter. After SLN biopsy, a primary electrode (seven-array model 70 Starburst needle electrode; RITA Medical Systems, Mountain View, CA) was inserted into the tumor under real-time US guidance. Then, the prongs of the needle electrode were deployed over a distance of 3 cm in all cases, and the RF generator (RITA model 1500) was activated and set to automatic, with power at 20 W, temperature of 95°C, and an ablation time of 15 min. Axillary lymph node dissection (ALND) was performed in patients with positive SLNs. Several months after RFA therapy, the ablated tumor tissue was excised by multiple mammotome biopsy and examined histologically or immunohistochemically with H&E staining, nicotinamide adenine dinucleotide (NADH)-diaphorase staining, and single-stranded (ss) DNA staining. All cases were followed-up after breast radiation and systemic therapies.

Results: The mean tumor size based on the ultrasonographic maximum dimension was 1.3 cm (range: 0.5–2.0 cm). Although complete response was histologically confirmed in only 8 cases, NADH-diaphorase and ssDNA staining did not demonstrate any viable tumor cells in any of the ablated lesions. At a mean follow-up of 60 months (follow-up range, 37–82 months), there were no cases of in-breast recurrence, although one patient died due to hepatic metastases. Cosmesis of the conserved breast was excellent or good in all of the cases, but a hard lump was persistent after RFA in half of the cases.

Conclusions: The long-term outcome of patients treated with RFA is encouraging with regard to cosmesis and local control. However, a persisted lump can cause patient discomfort, anxiety and fear. Therefore, further studies are needed to establish the optimal technique. Moreover, a prospective study will be required to determine the equivalency in local recurrence rates between the RFA therapy and conventional breast-conserving treatment.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-15-05.

Effects of linoleic acid, eicosapentaenoic acid, and docosahexaenoic acid on the growth and metastasis of MM48 mammary tumor transplants in mice

In this study, we investigated the effects of linoleic acid (LA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) on the growth, metastasis and cell proliferation of a murine mammary tumor (MM48) transplanted into mice. We also examined the effect of these treatments on survival and tumor fatty acids. The growth of the primary tumor, number of metastatic tumors in the lung, and cell proliferation of the tumor were significantly inhibited in the EPA and DHA groups compared with the control and/or LA groups. Mice in the EPA group survived significantly longer than those in the control and LA groups, while mice in the DHA group survived longer than those in the control group. While the ratio of arachidonic acid (AA)/higher PUFAs (polyunsaturated fatty acids) in tumors correlated with tumor growth and lung metastases, the ratio of AA/LA did not. Therefore, it appears that both EPA and DHA exert their effects by competing with AA, thereby lowering the formation of AA metabolites.

Relationship between nm23 expression and axillary and internal mammary lymph-node metastases in invasive breast-cancer

We examined the relationship between nm23 expression and clinicopathological variables in 144 patients with invasive breast cancer to assess the role of nm23 expression in estimating prognosis. Expression of nm23 was significantly associated with axillary lymph node (AX) metastases (p=0.0359) and internal mammary lymph node (IMN) metastases (p=0.0146), but not with age, menopausal status, histological type or grade, or tumor size. A univariate study revealed that survival significantly correlated with tumor size, AX and IMN metastases, whereas nm23 expression did not appear to be a significant prognostic factor. Among patients with negative AX, however, survival in patients without nm23 expression was lower than in those with nm23 expression (p=0.0778). Survival in patients with IMN metastases was significantly lower than those without IMN metastases among patients with positive AX (p=0.0073). In a multivariate study, AX and IMN metastases, and nm23 expression appeared to be significant prognostic factors for survival. This study suggests that nm23 expression may be an additional prognostic factor in patients with negative AX, while IMN metastases are an additional prognostic factor in those with positive AX.

Prognostic-significance of p53 and C-erbb-2 expression in operable breast-cancer

We analyzed associations among p53 and c-erbB-2 expression and clinicopathologic variables and, then ascertained whether p53 and/or c-erbB-2 expression would be useful for estimating prognosis in 105 breast cancer patients. There was no significant association between p53 and c-erbB-2 expression, but the combination of p53 and c-erbB-2 expression was significantly associated with axillary lymph node metastases. Although both p53 and c-erbB-2 expressions were significant prognostic factors by univariate analysis, they did not appear to be independent prognostic factors by multivariate analysis in which nodal status was introduced using the Cox model. When nodal status was excluded, however, p53 and c-erbB-2 expression each had independent prognostic value.

Nm23 and C-erbb-2 expression in invasive breast-cancer

We investigated whether nm23 and/or c-erbB-2 expression are useful for estimating the prognosis of invasive breast cancer patients. nm23 expression was significantly correlated with axillary (AX) and internal mammary lymph node (IMN) metastases, whereas c-erbB-2 expression was significantly correlated only with AX metastases. However, a univariate study revealed that survival was correlated significantly with tumor size, AX and IMN metastases, and c-erbB-2 expression, whereas nm23 expression was not an important prognostic factor. In a multivariate study, only AX and IMN metastases were significant prognostic factors. When AX and IMN metastases were excluded from the Cox model, only c-erbB-2 expression had independent prognostic value for survival. Therefore, we conclude that nm23 and/or c-erbB-2 expression may reflect the metastatic potential of breast cancer, but their prognostic value in combination is limited.

In vitro synergistic effects of zoledronic acid and calcium on viability of human epithelial cells

OBJECTIVE

Bisphosphonate-related osteonecrosis of the jaw is a common complication with defective wound healing of oral mucosa and frequently occurs in patients receiving zoledronic acid (ZA). The aim of this in vitro study was to investigate whether ZA has a cytotoxic effect at clinically relevant concentrations on epithelial cells when calcium conditions are altered.

METHODS

HaCaT human keratinocyte cells were treated with ZA in the presence of various concentrations of calcium. The concentrations of ZA included submicromolar ones, which are comparable with those found in the plasma of patients. Cell viability and apoptosis were assessed using MTT assay and annexin V flow cytometry.

RESULTS

Under standard culture conditions, cell growth was inhibited at 1 μM of ZA or above, but was unaffected by lower concentrations. However, when calcium concentrations were moderately increased, cell viability was decreased and apoptosis was induced at 0.2-0.3 μM of ZA. Moreover, a 50% reduction in serum in the hypercalcemic medium resulted in a significant decrease in cell viability at a much lower concentration (0.05 μM).

CONCLUSION

These results suggest that clinically relevant concentrations of ZA, which alone have little effects, can be toxic to the epithelial cells depending on the conditions of extracellular calcium.

Induced pluripotent stem cells generated from diabetic patients with mitochondrial DNA A3243G mutation

AIMS/HYPOTHESIS

The aim of this study was to generate induced pluripotent stem (iPS) cells from patients with mitochondrial DNA (mtDNA) mutation.

METHODS

Skin biopsies were obtained from two diabetic patients with mtDNA A3243G mutation. The fibroblasts thus obtained were infected with retroviruses encoding OCT4 (also known as POU5F1), SOX2, c-MYC (also known as MYC) and KLF4. The stem cell characteristics were investigated and the mtDNA mutation frequencies evaluated by Invader assay.

RESULTS

From the two diabetic patients we isolated four and ten putative mitochondrial disease-specific iPS (Mt-iPS) clones, respectively. Mt-iPS cells were cytogenetically normal and positive for alkaline phosphatase activity, with the pluripotent stem cell markers being detectable by immunocytochemistry. The cytosine guanine dinucleotide islands in the promoter regions of OCT4 and NANOG were highly unmethylated, indicating epigenetic reprogramming to pluripotency. Mt-iPS clones were able to differentiate into derivatives of all three germ layers in vitro and in vivo. The Mt-iPS cells exhibited a bimodal degree of mutation heteroplasmy. The mutation frequencies decreased to an undetectable level in six of 14 clones, while the others showed several-fold increases in mutation frequencies (51-87%) compared with those in the original fibroblasts (18-24%). During serial cell culture passage and after differentiation, no recurrence of the mutation or no significant changes in the levels of heteroplasmy were seen.

CONCLUSIONS/INTERPRETATION

iPS cells were successfully generated from patients with the mtDNA A3243G mutation. Mutation-rich, stable Mt-iPS cells may be a suitable source of cells for human mitochondrial disease modelling in vitro. Mutation-free iPS cells could provide an unlimited, disease-free supply of cells for autologous transplantation therapy.

P2-15-13: Oncologic and Cosmetic Outcome in Breast Cancer Patients Who Underwent “Moving Window” Operation

Background: An inappropriate skin incision on the breast reduces the cosmetic benefit of breast-conserving surgery (BCS).

Methods: To improve the cosmetic outcome, we have performed “Moving window” operation in which BCS can be performed via a periareolar incision (periareolar approach) and/or axillary incision (axillary approach) under direct visualization. Axillary lymph node dissection is also performed via an axillary incision.

Results: Periareolar approach was performed in 65 patients and axillary approach in 43 patients. Average operation time was 130 minutes in periareolar approach and 131 minutes in axillary approach. Average blood loss was 37 mL and 50 mL, respectively. Postoperatively, the surgical margin of breast tissue was histologically confirmed to be negative in 107 (99%) of 108 patients, while two patients underwent reoperation because of positive surgical margin. Fifty-two patients (85%) in periareolar approach and 37 patients (86%) in axillary approach had excellent or good cosmetic results.

With a mean follow-up of 36 months, one patient with DCIS developed in-breast recurrence, while 3 patients who had neoadjuvant chemotherapy developed in-breast recurrence.

Conclusion: The moving window operation can improve a cosmetic outcome of the conserved breast without compromising the oncological safety.

Moreover, it can reduce operating time and blood loss when compared with the endoscope-assisted BCS.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-15-13.

P3-07-44: Feasibility of Axillary Reverse Mapping during Sentinel Lymph Node Biopsy in Breast Cancer

Background: The axillary reverse mapping (ARM) procedure is based on the hypothesis that the lymphatic drainage from the upper arm is different from that of the breast. However, the oncologic safety of the procedure has not yet been determined.

Methods: The ARM nodes were identified using a fluorescence imaging system. Sentinel lymph node (SLN) biopsy was performed in patients with clinically uninvolved nodes. If the SLN was positive, ALND was performed with removal of ARM nodes. Otherwise, the identified ARM nodes were preserved unless they were the same as the SLN.

Results: The ARM node was identified in 30 of 91 patients who underwent SLN biopsy, and it was the same as the SLN in 23 patients. However, in 13 patients with a positive SLN who subsequently underwent ALND, ARM nodes were tumor-free when they were not the same as the positive SLN.

Conclusions: There are limits to the principle of non-overlap between breast and arm nodes. However, it may be feasible to spare ARM nodes during ALND in patients with clinically negative nodes.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-07-44.

A study of lesions induced in Seriola dumerili infected naturally with Streptococcus dysgalactiae

An outbreak of disease in Seriola dumerili occurred from August to October in 2007 and 2008. The fish developed lesions of the caudal peduncle, pectoral and/or dorsal fin and the heart. The lesions were characterized by moderate to severe infarction with areas of microabscessation and multifocal granulomatous inflammation associated with the presence of Streptococcus dysgalactiae antigen. This is the first report to describe the immunohistology of the lesions induced in S. dumerili following natural infection with S. dysgalactiae.

A model for analysis of the yield and the level of clustering of radiation-induced DNA-strand breaks in hydrated plasmids

Although it is widely accepted that the spatial distribution of strand breaks is highly relevant to the biological consequences of radiation, the extent to which strand breaks are clustered is not usually demonstrated directly from the experimental data. To evaluate the spatial distribution of radiation-induced strand breaks, the authors have developed a model for the generation of strand breaks after irradiation. The model assumes that (1) a radiation track has a certain probability of 'hitting' a plasmid, (2) the radiation generates strand break(s) by chance within a relatively small region that could produce double-strand breaks and (3) the number of strand breaks generated within the region follows a Poisson distribution. To find out whether the model is valid, the authors compared the calculated values with the experimental data obtained by a plasmid DNA assay. Taking into account the inherent bias of the plasmid assay, the model described well the experimental results of hydrated plasmids exposed to radiation.

Induction of DNA DSB and its rejoining in clamped and non-clamped tumours after exposure to carbon ion beams in comparison to X rays

We studied double-strand breaks (DSB) induction and rejoining in clamped and non-clamped transplanted tumours in mice leg after exposure to 80 keV µm(-1) carbon ions and X rays. The yields of DSB in the tumours were analysed by a static-field gel electrophoresis. The OER of DSB after X rays was 1.68±0.31, and this value was not changed after 1 h rejoining time (1.40±0.26). These damages in oxygenated conditions were rejoined 60-70% within 1 h in situ. No difference was found between the exposure to X rays and carbon ions for the induction and rejoining of DSB. Thus, the values of OER and rejoined fraction after exposure to carbon ions were similar to those after X rays, and the calculated relative biological effectivenesses of carbon ion were around 1 under both oxygen conditions. The yields of DSB in vivo depend on exposure doses, oxygen conditions and rejoining time, but not on the types of radiation quality.

Adipose tissue-specific dysregulation of angiotensinogen by oxidative stress in obesity

Adipose tissue expresses all components of the renin-angiotensin system including angiotensinogen (AGT). Recent studies have highlighted a potential role of AGT in adipose tissue function and homeostasis. However, some controversies surround the regulatory mechanisms of AGT in obese adipose tissue. In this context, we here demonstrated that the AGT messenger RNA (mRNA) level in human subcutaneous adipose tissue was significantly reduced in obese subjects as compared with nonobese subjects. Adipose tissue AGT mRNA level in obese mice was also lower as compared with their lean littermates; however, the hepatic AGT mRNA level remained unchanged. When 3T3-L1 adipocytes were cultured for a long period, the adipocytes became hypertrophic with a marked increase in the production of reactive oxygen species. Expression and secretion of AGT continued to decrease during the course of adipocyte hypertrophy. Treatment of the 3T3-L1 and primary adipocytes with reactive oxygen species (hydrogen peroxide) or tumor necrosis factor alpha caused a significant decrease in the expression and secretion of AGT. On the other hand, treatment with the antioxidant N-acetyl cysteine suppressed the decrease in the expression and secretion of AGT in the hypertrophied 3T3-L1 adipocytes. Finally, treatment of obese db/db mice with N-acetyl cysteine augmented the expression of AGT in the adipose tissue, but not in the liver. The present study demonstrates for the first time that oxidative stress dysregulates AGT in obese adipose tissue, providing a novel insight into the adipose tissue-specific interaction between the regulation of AGT and oxidative stress in the pathophysiology of obesity.