**6.1.2 HSP as cancer diagnostic markers in COPD patients**

HSP were found to be expressed on the surface of tumor cell and extracellular HSP were reported in plasma of both cancer and non-cancer patients. As HSP are highly immunogenic their cell surface and extracellular expression was employed in the production of vaccines as well as an approach for cancer detection.

Zhong et al, 2003 first decribed the diagnostic significance of extracellular HSP70 and 90 in NSCLC patients. The assay was performed in a group of 49 NCSLC patients and 40 healthy volunteers. The diagnostic utility of the HSP70 expression showed a modest sensitivity 0.74 and specificity 0.73; area under the curve AUC=0.73; while HSP90 antibodies were of poor performance AUC-0.602.

Wang et al, 2010 also tried to characterize the levels of expression of HSP70 and HSP27 in plasma and lymphocytes. They compared the expression of these chaperones in 99 coal miners without NSCLC, 51 coal miners with NSCLC and 42 patients that were not coalminers. They found higher levels of plasma HSP27 and HSP70 in coal miners, which corresponded to a higher risk for lung cancer. Lymphocytes of coal miners with NSCLC had the lowest levels of intracellular HSP70 compared to coal miners and non-coal miners.

The presence of αB antibodies in NSCLC patients was also reported. Cherneva et al, 2010 compared the levels of expression of αB-crystallin in 51 NSCLC patients, 38 high risk COPD patients and 52 age and sex matched healthy volunteers. They found that the expression of αB crystalline antibodies was significantly higher in NSCLC patients in comparison to age and sex matched healthy volunteers - (p<0.001). αB-crystallin antibodies showed sensitivity 62% and specificity 72% in discerning cancer patients among healthy volunteers.

The clinical significance of αB-crystallin antibodies however is limited while comparing the healthy volunteers to the high risk group of COPD patients. A potential explanation of this

tumour stage (p = 0.042). Patients whose tumours had nuclear staining had shorter overall survival time in comparison to those that lacked staining (log-rank test p = 0.002). This supports the hypothesis that the nuclear positivity of the tumours refers to a more aggressive tumour biology. The nuclear positivity of αB in NSCLC stratifies patients from II and III stage in risk subgroups. Keeping in mind that more than 75% of patients are diagnosed at stage III, the introduction and validation of prognostic markers at this stage

 To sum up the role of heat shock proteins in NSCLC we can say that the high molecular chaperones are important molecular mechanisms in lung cancerogenesis, probably contributing by their chaperoning abilities related to other oncogenic molecules - (HSP90,70) as well as by performing their role in apoptosis – (HSP60,70). They could be used in cancer treatment as their inhibition (HSP90) is associated with overwhelming of chemoresistance (Shimamura et al, 2005, 2008) – or their induction (HSP70) as a way of sensitizing tumors to chemo- and radiotherapy (Gehrmann, 2006) The small heat shock proteins are probably related to the regulation of apoptosis, cytoskeletal stability, chaperoning of antioxidant enzymes and prevention of oxidative stress. Their clinical significance is related to their applicaton as markers for chemoresistance - (HSP27), or risk stratification and survival (αB-

HSP were found to be expressed on the surface of tumor cell and extracellular HSP were reported in plasma of both cancer and non-cancer patients. As HSP are highly immunogenic their cell surface and extracellular expression was employed in the production of vaccines as

Zhong et al, 2003 first decribed the diagnostic significance of extracellular HSP70 and 90 in NSCLC patients. The assay was performed in a group of 49 NCSLC patients and 40 healthy volunteers. The diagnostic utility of the HSP70 expression showed a modest sensitivity 0.74 and specificity 0.73; area under the curve AUC=0.73; while HSP90 antibodies were of poor

Wang et al, 2010 also tried to characterize the levels of expression of HSP70 and HSP27 in plasma and lymphocytes. They compared the expression of these chaperones in 99 coal miners without NSCLC, 51 coal miners with NSCLC and 42 patients that were not coalminers. They found higher levels of plasma HSP27 and HSP70 in coal miners, which corresponded to a higher risk for lung cancer. Lymphocytes of coal miners with NSCLC had the lowest levels of intracellular HSP70 compared to coal miners and non-coal miners.

The presence of αB antibodies in NSCLC patients was also reported. Cherneva et al, 2010 compared the levels of expression of αB-crystallin in 51 NSCLC patients, 38 high risk COPD patients and 52 age and sex matched healthy volunteers. They found that the expression of αB crystalline antibodies was significantly higher in NSCLC patients in comparison to age and sex matched healthy volunteers - (p<0.001). αB-crystallin antibodies showed sensitivity

The clinical significance of αB-crystallin antibodies however is limited while comparing the healthy volunteers to the high risk group of COPD patients. A potential explanation of this

62% and specificity 72% in discerning cancer patients among healthy volunteers.

would undoubtedly help in predicting recurrence and improving clinical prognosis.

**6.1.2 HSP as cancer diagnostic markers in COPD patients** 

well as an approach for cancer detection.

performance AUC-0.602.

crystallin).

could be that the major characteristic of this pathology is the increased oxidative stress and chronic systemic inflammation, predominantly localized in the lungs.This may provoke reactive αB-crystallin protein overexpression in COPD patients, as one of its function is antioxidation (Aggeli et al, 2008).

Analysing the levels of antibodies of αB-crystallin in the plasma of patients with NSCLC and their clinicopathological chracteristic, Cherneva et al, found no significance between pathological parameters and this biological marker. This however was not the issue when concerning the lymphogenic spread of the disease. The levels of antibodies in patients with lymph node metastases was higher compared to those without them. The reason for this remains elusive and requires further investigation. The ROC curve analysis showed decent characteristics in discerning patients with and without metastatic spread –AUC 0.667 (95%CI – 0.515-0.820) sensitivity- 60% and specificity –70% at a cut-off 0.381. It should be however carefully taken in consideration that the clinical staging does not envisage the molecular one and the presence of already spread micrometastatic disease in N0 patients is obscure. Whether the higher rate of antibodies in patients with lymph metastases corresponds to a better immune reactivation and host defence remains a matter of question, since patients should be followed up.

Summarizing, the expression of heat shock proteins in NSCLC patients is of limited significance as a diagnostic approach, either alone or in a combination panel. The presence of αB-crystallin antibodies in plasma of NSCLC patients seems to be due the reactivation of the immune system and is unspecific as far as it is provoked under various stress conditions. The higher levels of the antibodies detected in patients with lymphogenic metastatic spread could be of clinical application as far as they could be used as markers for risk of recurrence and patients' prognosis.
