The aim of the study is the assessment of the intensity of the infiltration of tumor-associated macrophages (TAMs) CD68⁺/iNOS⁻ and Tregs CD8⁺/FoxP3⁺ in colorectal cancer (CRC) patients as prognostic factors with respect to disease-free survival (DFS) and overall survival (OS). In this retrospective study, tissue samples were obtained from 89 patients undergoing resection for CRC (stage IIA, pT3N0M0 and stages IIIB and IIIC, pT3N1-2M0). Recurrence was observed in 45 patients at the time of the follow-up (10 local recurrences, 35 distant metastases). In patients with recurrence the following were present: a tendency to an older average age at the time of diagnosis (p = 0.07), higher nodal involvement (p = 0.002) and more advanced clinical disease (p = 0.01). The analysis of the clinical data and immunohistochemical studies were performed with the methodology of identification of TAM and Treg subsets in histological sections, with the aim to use it in routine clinical management. Both DSF and OS were the clinical parameters assessed in the study. The presence of intense infiltration of TAMs in the tumor stroma was related to shorter DFS (p = 0.005) and OS (p = 0.006). The opposite tendency was observed in the tumor front (p = 0.061). The relative risks of recurrence and cancer-related death were more than twice higher in the group of patients with intense infiltration of TAMs in the tumor stroma (RR 2.05, 95% CI 1.33–3.14; p = 0.001 and RR 2.08, 95% CI 1.28–3.39; p = 0.003, respectively). Intense infiltration of Tregs in the tumor stroma was related to shorter DFS and OS (p < 0.0001). The relative risks of recurrence and death in a group of patients with intense infiltration of Tregs in the tumor stroma were more than 12 times higher than in patients with less intense infiltration (RR 12.3, 95% CI 5.44–27.9; p < 0.0001 and RR 12.5, 95% CI 4.9–32.4; p < 0.0001, respectively). Infiltration of TAMs CD68⁺/iNOS⁻ and Tregs CD8⁺/FoxP3⁺ in the tumor stroma are negative prognostic factors with a positive correlation between them. Tregs may constitute an independent prognostic factor in patients with CRC.

Tumor suppressor PTEN is known to control a variety of processes related to cell survival, proliferation, and growth. PTEN expression is considered as a prognostic factor in some human neoplasms like breast, prostate, and thyroid cancer. In this study we analyzed the influence of PTEN expression on the outcome of a randomized clinical trial of conventional versus 7-days-a-week postoperative radiotherapy for squamous cell cancer of the head and neck. The patients with cancer of the oral cavity, oropharynx, and larynx were randomized to receive 63 Gy in fractions of 1.8 Gy given 5 days a week (CF) or 7 days a week (p-CAIR). Out of 279 patients enrolled in the study, 147 paraffin blocks were available for an immunohistochemical assessment of PTEN. To evaluate the prognostic value of PTEN expression and the effect of fractionation relative to PTEN, the data on the outcome of a randomized clinical trial were analyzed. Tumors with a high intensity of PTEN staining had significant gain in the loco-regional control (LRC) from p-CAIR (5-year LRC 92.7% vs. 70.8%, for p-CAIR vs. CF, p = 0.016, RR = 0.26). By contrast, tumors with low intensity of PTEN did not gain from p-CAIR (5-year LRC 56.2% vs. 47.2%, p = 0.49, RR = 0.94). The intensity of PTEN highly affected the LRC in a whole group of 147 patients (5-year LRC 80.9% vs. 52.3% for high vs. low PTEN, p = 0.0007, RR = 0.32). In multivariate Cox analysis, including neck node involvement, EGFR, nm23, Ki-67, p53, cyclin D1, tumor site and margins, PTEN remained an independent predictor of LRC (RR = 2.8 p = 0.004). These results suggest that PTEN may serve as a potent prognostic and predictive marker in postoperative radiotherapy for high-risk squamous cell cancer of the head and neck.

The aim of the study was to determine expression of the PTEN suppressor gene in colorectal adenocarcinoma and its precancerous lesions (adenomatous polyps) in correlation with common clinical and histopathological features. Forty-four patients with adenomatous polyps and 32 with primary adenocarcinoma of the colon or rectum were enrolled in the study. They underwent endoscopic removal of polyps or major surgery and postoperative adjuvant chemo- and radiotherapy depending on staging of the disease. No patient had received chemotherapy and/or radiotherapy before the surgery. PTEN expression was evaluated using immunohistochemical staining on paraffin-embedded specimens and compared to clinicopathological features of tumors. In colorectal cancers, PTEN expression was found to be significantly lower than in normal intestinal mucosa and adenomatous polyps. That was associated with complete loss of PTEN expression observed more frequently in colorectal cancer, contrary to reduction of PTEN expression occurring mostly in polyps. A correlation between polyp diameter and loss of PTEN was demonstrated as well as between tumor size and TNM advanced stage and PTEN expression. The obtained results suggest that the PTEN/PI3K/Akt pathway may play an important role in early stages of sporadic colorectal carcinogenesis and reduced PTEN expression in late oncogenesis is associated with some adverse clinical and pathological features.

Compared to current treatments including surgery, radiation therapy, and chemotherapy, PDT offers the advantage of an effective and selective method of destroying diseased tissues without damaging surrounding healthy tissues. One of the aspects of antitumour effectiveness of PDT is related to the distribution of photosensitizing drugs. The localization of photosensitizers in cytoplasmic organelles during PDT plays a major role in the cell destruction; therefore, intracellular localization of Ph in malignant and normal cells was investigated. The cell lines used throughout the study were: human malignant A549, MCF-7, Me45 and normal endothelial cell line HUV-EC-C. After incubation with Ph cells were examined using fluorescence and confocal microscopy to visualize the photosensitizer accumulation. For cytoplasm and mitochondria identification, cells were stained with CellTracker Green and MitoTracker Green, respectively. Distribution of Ph was different in malignant and normal cells and dependent on the incubation time. The maximal concentration of Ph in two malignant cell lines (A549 and MCF-7) was observed after 4 hours of incubation, and the most intensive signal was observed around the nuclear envelope. Intracellular distribution of Ph in the Me45 cell line showed that the fluorescence emitted by Ph overlaid that from MitoTracker. This indicates preferential accumulation of the sensitizer in mitochondria. Our results based on the mitochondrial localization support the idea that PDT can contribute to elimination of malignant cells by inducing apoptosis, which is of physiological significance.