Impact of multidisciplinary team meetings on the management of patients with breast cancer in a large private healthcare facility

AIMS

Multidisciplinary meetings (MDMs) play a crucial role in decision-making in breast cancer patient care. This study aimed to firstly assess the impact of breast cancer MDMs in decision-making for breast cancer patients and secondly to determine the concordance between MDM recommendations and implementation of clinical practice.

METHODS

Patient cases to be presented at the weekly breast cancer MDMs were identified and prospectively enrolled. Management plans were predicted by the treating surgeon with the pre-MDM management plans then compared to MDM recommendations. Changes in decision-making were assessed in the following domains: further surgery, systemic therapy (endocrine, chemotherapy or targeted), radiotherapy, enrolment in a clinical trial, further investigations, and referral to other specialists or services. Patient records were subsequently reviewed at 3 months post-MDM to assess the rate of implementation of MDM recommendations and any reasons for discordance.

RESULTS

Out of 50 cases, 66% (CI 53-79%; p < .005) experienced a change in management plan as a result of MDM discussion, with a total of 66 episodes of recorded change per decision-making domain affecting the following: further surgery (7.6%), endocrine therapy (4.5%), chemotherapy (19.7%), targeted therapy (4.5%), radiotherapy (18.2%), enrolment for a clinical trial (12.1%), additional investigations (22.7%), and further referrals (10.6%). MDM recommendations were implemented in 83.7% of cases.

CONCLUSION

The breast cancer MDMs were found to substantially impact on the management plans for breast cancer patients, with 83.7% of MDM recommendations being implemented into clinical practice. This study reinforces the importance of MDMs in the management of these patients, as well as highlighting the need for further investigating and addressing the potential barriers to the implementation of MDM recommendations.

γH2AX in mouse embryonic stem cells: Distribution during differentiation and following γ-irradiation

Phosphorylated histone H2AX (γH2AX) represents a sensitive molecular marker of DNA double-strand breaks (DSBs) and is implicated in stem cell biology. We established a model of mouse embryonic stem cell (mESC) differentiation and examined the dynamics of γH2AX foci during the process. Our results revealed high numbers of γH2AX foci in undifferentiated mESCs, decreasing as the cells differentiated towards the endothelial cell lineage. Notably, we observed two distinct patterns of γH2AX foci: the typical discrete γH2AX foci, which colocalize with the transcriptionally permissive chromatin mark H3K4me3, and the less well-characterized clustered γH2AX regions, which were only observed in intermediate progenitor cells. Next, we explored responses of mESCs to γ-radiation (137Cs). Following exposure to γ-radiation, mESCs showed a reduction in cell viability and increased γH2AX foci, indicative of radiosensitivity. Despite irradiation, surviving mESCs retained their differentiation potential. To further exemplify our findings, we investigated neural stem progenitor cells (NSPCs). Similar to mESCs, NSPCs displayed clustered γH2AX foci associated with progenitor cells and discrete γH2AX foci indicative of embryonic stem cells or differentiated cells. In conclusion, our findings demonstrate that γH2AX serves as a versatile marker of DSBs and may have a role as a biomarker in stem cell differentiation. The distinct patterns of γH2AX foci in differentiating mESCs and NSPCs provide valuable insights into DNA repair dynamics during differentiation, shedding light on the intricate balance between genomic integrity and cellular plasticity in stem cells. Finally, the clustered γH2AX foci observed in intermediate progenitor cells is an intriguing feature, requiring further exploration.

Distinguishing hyperglycemic changes by Set7 in vascular endothelial cells

RATIONALE

Epigenetic changes are implicated in the persisting vascular effects of hyperglycemia. The precise mechanism whereby chromatin structure and subsequent gene expression are regulated by glucose in vascular endothelial cells remain to be fully defined.

OBJECTIVE

We have studied the molecular and functional mechanism whereby the Set7 methyltransferase associates with chromatin formation and histone methylation in vascular cells in response to current and previous exposure to glucose.

METHODS AND RESULTS

To characterize the molecular and functional identity of the Set7 protein, we used vascular cells overexpressing or lacking Set7. Chromatin fractionation for mono-methylation of lysine 4 on histone H3 identified methyltransferase activity. Immunofluorescence experiments strongly suggest that Set7 protein accumulates in the nucleus in response to hyperglycemia. Moreover, activation of proinflammatory genes by high glucose is dependent on Set7 but distinguished by H3K4m1 gene patterns. We show that transient hyperglycemia regulates the expression of proinflammatory genes in vascular endothelial cells in vitro and the persistent increase in glucose-induced gene expression in the aorta of nondiabetic mice.

CONCLUSIONS

This study uncovers that the response to hyperglycemia in vascular endothelial cells involves the H3K4 methyltransferase, Set7. This enzyme appears to regulate glucose-induced chromatin changes and gene expression not only by H3K4m1-dependent but also H3K4m1-independent pathways. Furthermore, Set7 appears to be responsible for sustained vascular gene expression in response to prior hyperglycemia and is a potential molecular mechanism for the phenomenon of hyperglycemic memory.

Molecular model of naphthalene-induced DNA damage in the murine lung

Airway epithelial damage and repair represents a novel therapeutic target in asthma and chronic obstructive pulmonary disease. An established mouse model of airway epithelial damage involves the Clara cell cytotoxicity of parenterally administered naphthalene, an important environmental toxicant with genotoxic and carcinogenic potential. The objective of the current study was to investigate naphthalene-induced toxicity and to identify and quantify DNA double-strand breaks in a murine naphthalene model of airway epithelial damage. Male C57/BL6 mice were injected with 200 mg/kg naphthalene and culled at 12-, 24-, 48- and 72-h time points. Lung function and bronchoalveolar lavage was performed and the lungs were dissected for histological analysis and for quantitation of DNA double-strand breaks using γH2AX as a molecular marker. Mice injected with naphthalene had increased epithelial denudation, bronchoalveolar lavage fluid cellularity and reactivity to nebulized methacholine chloride as compared to corn oil vehicle controls. Histological changes were most pronounced at the 12- and 24-h time points. DNA double-strand breaks, quantitated as the number of γH2AX foci per cell, were highest at the 24- and 48-h time points. All parameters had decreased at the 72-h time point, consistent with airway re-epithelization and cellular repair. Our findings indicate a time-dependent accumulation of γH2AX foci in mouse airway epithelial cells following administration of naphthalene. Naphthalene airway epithelial injury constitutes a model of DNA double-strand breaks in mice, which can be adapted as a suitable model for further investigation of genotoxic damage for evaluating the efficacy of potential therapeutics.

Clonogenic assay: adherent cells

The clonogenic (or colony forming) assay has been established for more than 50 years; the original paper describing the technique was published in 1956. Apart from documenting the method, the initial landmark study generated the first radiation-dose response curve for X-ray irradiated mammalian (HeLa) cells in culture. Basically, the clonogenic assay enables an assessment of the differences in reproductive viability (capacity of cells to produce progeny; i.e. a single cell to form a colony of 50 or more cells) between control untreated cells and cells that have undergone various treatments such as exposure to ionising radiation, various chemical compounds (e.g. cytotoxic agents) or in other cases genetic manipulation. The assay has become the most widely accepted technique in radiation biology and has been widely used for evaluating the radiation sensitivity of different cell lines. Further, the clonogenic assay is commonly used for monitoring the efficacy of radiation modifying compounds and for determining the effects of cytotoxic agents and other anti-cancer therapeutics on colony forming ability, in different cell lines. A typical clonogenic survival experiment using adherent cells lines involves three distinct components, 1) treatment of the cell monolayer in tissue culture flasks, 2) preparation of single cell suspensions and plating an appropriate number of cells in petri dishes and 3) fixing and staining colonies following a relevant incubation period, which could range from 1-3 weeks, depending on the cell line. Here we demonstrate the general procedure for performing the clonogenic assay with adherent cell lines with the use of an immortalized human keratinocyte cell line (FEP-1811). Also, our aims are to describe common features of clonogenic assays including calculation of the plating efficiency and survival fractions after exposure of cells to radiation, and to exemplify modification of radiation-response with the use of a natural antioxidant formulation.

Evaluation of the efficacy of radiation-modifying compounds using γH2AX as a molecular marker of DNA double-strand breaks

Radiation therapy is a widely used therapeutic approach for cancer. To improve the efficacy of radiotherapy there is an intense interest in combining this modality with two broad classes of compounds, radiosensitizers and radioprotectors. These either enhance tumour-killing efficacy or mitigate damage to surrounding non-malignant tissue, respectively. Radiation exposure often results in the formation of DNA double-strand breaks, which are marked by the induction of H2AX phosphorylation to generate γH2AX. In addition to its essential role in DDR signalling and coordination of double-strand break repair, the ability to visualize and quantitate γH2AX foci using immunofluorescence microscopy techniques enables it to be exploited as an indicator of therapeutic efficacy in a range of cell types and tissues. This review will explore the emerging applicability of γH2AX as a marker for monitoring the effectiveness of radiation-modifying compounds.

Urinary cadmium as indicator of renal cadmium in humans: an autopsy study

OBJECTIVE

To estimate the equivalent cadmium levels in renal cortex and in urine, as based on autopsy analysis of subjects not exposed to cadmium occupationally.

METHODS

The levels of Cd were determined in renal cortex, liver, urine and urinary bladder of 39 subjects deceased at the age 42 +/- 14 years. Flame atomic absorption spectrometry (kidneys, liver) and flameless AAS (urine, bladder) were used.

RESULTS

The urinary cadmium level determined post mortem is strongly correlated with the renal Cd levels. Eliminating cases with high urinary proteins and extrapolating from sets of data with elevated urinary protein concentration to its normal range yielded a value of 1.7 microg/g creatinine as equivalent to the renal level of 50 microg/g w.w.

CONCLUSIONS

It seems possible to use monitoring data for cadmium in urine and in renal cortex in a coherent way.

Cadmium, zinc, copper, and metallothionein levels in the kidney and liver of inhabitants of upper Silesia (Poland)

The levels of Cd, Zn, Cu and metallothionein (MT) were determined in renal cortex and liver of 75 subjects decreased in the period 1986-1989 in the area of Upper Silesia (Katowice). The mean age of the population studied was 53.6 +/- 14.6 years. The determined levels (mean +/- SD) were: 43.1 +/- 23.5 micrograms Cd/g; 52.5 +/- 17.4 micrograms Zn/g; 2.2 +/- 0.7 microgram Cu/g; 0.80 +/- 0.36 mumol Hg/g in renal cortex and 3.5 +/- 2.5 micrograms Cd/g; 82.8 +/- 34.3 micrograms Zn/g; 4.5 +/- 2.6 micrograms Cu/g; 0.69 +/- 0.44 mumol Hg/g in the liver. The level of Cd in renal cortex was 40% higher in smokers compared to nonsmokers and was independent of the gender. Whole-body retention of Cd was 34.1 +/- 18.5 mg; smoking elevated the value from 27.1 to 38.2 mg. Compared with a similar study made in central Poland (Lódź), a significant difference was found only regarding the level of Zn and MT in the liver, pointing to the possibility that exposure to this element in the region of Upper Silesia may be higher.

[A simple testing installation for the production of aerosols with constant bacteria-contaminated concentrations]

A simple experimental set for the production and investigation of bacterially contaminated solid-state aerosols with constant concentration is described. The experimental set consists mainly of a fluidized bed-particle generator within a modified chamber for formaldehyde desinfection. The special conditions for the production of a defined concentration of particles and microorganisms are to be found out empirically. In a first application aerosol-sizing of an Andersen sampler is investigated. The findings of Andersen (1) are confirmed with respect to our experimental conditions.

Cadmium metabolism in cdm/cdm mice

The uptake and metabolism of cadmium by cadmium-susceptible (+/+) and cadmium-resistant (cdm/cdm) strains of mice have been compared. These strains did not differ with respect to the quantitative uptake of cadmium into liver, kidney, or testis. After intraperitoneal administration of a nontoxic dose, more than 80% of the cadmium in liver and testis of both strains is bound to low molecular weight proteins. The chromatographic behavior of these cadmium-binding proteins is not affected by cdm genotype.