Melanoma secretion of transforming growth factor-β2 leads to loss of epidermal AMBRA1 threatening epidermal integrity and facilitating tumour ulceration

BACKGROUND

For patients with early American Joint Committee on Cancer (AJCC)-stage melanoma the combined loss of the autophagy regulatory protein AMBRA1 and the terminal differentiation marker loricrin in the peritumoral epidermis is associated with a significantly increased risk of metastasis.

OBJECTIVES

The aim of the present study was to evaluate the potential contribution of melanoma paracrine transforming growth factor (TGF)-β signalling to the loss of AMBRA1 in the epidermis overlying the primary tumour and disruption of epidermal integrity.

METHODS

Immunohistochemistry was used to analyse AMBRA1 and TGF-β2 in a cohort of 109 AJCC all-stage melanomas, and TGF-β2 and claudin-1 in a cohort of 30 or 42 AJCC stage I melanomas, respectively, with known AMBRA1 and loricrin (AMLo) expression. Evidence of pre-ulceration was analysed in a cohort of 42 melanomas, with TGF-β2 signalling evaluated in primary keratinocytes.

RESULTS

Increased tumoral TGF-β2 was significantly associated with loss of peritumoral AMBRA1 (P < 0·05), ulceration (P < 0·001), AMLo high-risk status (P < 0·05) and metastasis (P < 0·01). TGF-β2 treatment of keratinocytes resulted in downregulation of AMBRA1, loricrin and claudin-1, while knockdown of AMBRA1 was associated with decreased expression of claudin-1 and increased proliferation of keratinocytes (P < 0·05). Importantly, we show loss of AMBRA1 in the peritumoral epidermis was associated with decreased claudin-1 expression (P < 0·05), parakeratosis (P < 0·01) and cleft formation in the dermoepidermal junction (P < 0·05).

CONCLUSIONS

Collectively, these data suggest a paracrine mechanism whereby TGF-β2 causes loss of AMBRA1 overlying high-risk AJCC early-stage melanomas and reduced epidermal integrity, thereby facilitating erosion of the epidermis and tumour ulceration.

Epidermal autophagy and beclin 1 regulator 1 and loricrin: a paradigm shift in the prognostication and stratification of the American Joint Committee on Cancer stage I melanomas

BACKGROUND

The updated American Joint Committee on Cancer (AJCC) staging criteria for melanoma remain unable to identify high-risk stage I tumour subsets.

OBJECTIVES

To determine the utility of epidermal autophagy and beclin 1 regulator 1 (AMBRA1)/loricrin (AMLo) expression as a prognostic biomarker for AJCC stage I cutaneous melanoma.

METHODS

Peritumoral AMBRA1 expression was evaluated in a retrospective discovery cohort of 76 AJCC stage I melanomas. AMLo expression was correlated with clinical outcomes up to 12 years in two independent powered, retrospective validation and qualification cohorts comprising 379 AJCC stage I melanomas.

RESULTS

Decreased AMBRA1 expression in the epidermis overlying primary melanomas in a discovery cohort of 76 AJCC stage I tumours was associated with a 7-year disease-free survival (DFS) rate of 81·5% vs. 100% survival with maintained AMBRA1 (P < 0·081). Following an immunohistochemistry protocol for semi-quantitative analysis of AMLo, analysis was undertaken in validation (n = 218) and qualification cohorts (n = 161) of AJCC stage I melanomas. Combined cohort analysis revealed a DFS rate of 98·3% in the AMLo low-risk group (n = 239) vs. 85·4% in the AMLo high-risk cohort (n = 140; P < 0·001). Subcohort multivariate analysis revealed that an AMLo hazard ratio (HR) of 4·04 [95% confidence interval (CI) 1·69-9·66; P = 0·002] is a stronger predictor of DFS than Breslow depth (HR 2·97, 95% CI 0·93-9·56; P = 0·068) in stage IB patients.

CONCLUSIONS

Loss of AMLo expression in the epidermis overlying primary AJCC stage I melanomas identifies high-risk tumour subsets independently of Breslow depth. What's already known about this topic? There is an unmet clinical need for biomarkers of early-stage melanoma. Autophagy and beclin 1 regulator 1 (AMBRA1) is a proautophagy regulatory protein with known roles in cell proliferation and differentiation, and is a known tumour suppressor. Loricrin is a marker of epidermal terminal differentiation. What does this study add? AMBRA1 has a functional role in keratinocyte/epidermal proliferation and differentiation. The combined decrease/loss of peritumoral AMBRA1 and loricrin is associated with a significantly increased risk of metastatic spread in American Joint Committee on Cancer (AJCC) stage I tumours vs. melanomas, in which peritumoral AMBRA1 and loricrin are maintained, independently of Breslow depth. What is the translational message? The integration of peritumoral epidermal AMBRA1/loricrin biomarker expression into melanoma care guidelines will facilitate more accurate, personalized risk stratification for patients with AJCC stage I melanomas, thereby facilitating stratification for appropriate follow-up and informing postdiagnostic investigations, including sentinel lymph node biopsy, ultimately resulting in improved disease outcomes and rationalization of healthcare costs.

[The relationship between pre-operative emotional states and stress-linked parameters in surgical patients (author's transl)]

The relationship between the pre-operative emotional state and stress-linked endocrine, respiratory, metabolic and cardiovascular parameters was investigated. It could be demonstrated that the patients' affective state, especially anxiety, depression, feeling of debility, affected endocrine and metabolic function (concentration of serum cortisone and of serum free fatty acids respectively) as well as cardiovascular function, viz.: heart rate, systolic blood pressure and tension-time index. Subjects in a poor pre-operative state of mind showed statistically significant increases in serum cortisone levels and heart rate and also a higher tension-time index. Patients in a depressed state also had markedly higher heart rates immediately before the operation than had those who were in a cheerful confident mood. On the other hand the serum levels of free fatty acids, determined immediately before the operation, were higher in the latter than they were in patients who felt weak and debilitated. The observations are interpreted as the result of increased tone of the sympathetic nervous system in the presence of sthenic affects. The fact that these observations were made in patients undergoing the usual preparatory procedure prior to anaesthesia and surgery indicates that the routine preoperative preparations do not take sufficient account of the psychic and psychophysiological condition of the patient. Both the somatic and the emotional and psychophysiological responses should be considered in the preparation of the patient for surgery. Verification of the therapeutic success should include psychometric methods and measurement of stress-linked parameters.

[Electrostimulation anaesthesia and neurolept anaesthesia for cholecystectomy. A comparative study (author's transl)]

In 26 patients, undergoing cholecystectomy under electrostimulation anaesthesia (ESA) (n = 14) and neurolept anesthesia (NLA) (n = 12) the effects on consumption of anaesthetic agents, mean arterial pressure, heart rate, blood gases, lung function, serum cortisol and awareness are compared. Consumption of anaesthetic agents was 21.6 per cent in ESA compared to 100 per cent in NLA. Mean arterial pressure, heart rate and serum cortisol were elevated in ESA compared to NLA, probably due to elevated stress. Awareness 4 hours after anaesthesia was higher in ESA, probably due to less persistence of anaesthetics. Blood gases 1 hour after operation were slightly better after ESA, as also were forced vital capacity and peak flow one day after operation. The results are discussed.