Quantum dots-based double imaging combined with organic dye imaging to establish an automatic computerized method for cancer Ki67 measurement

Colorectal cancer histopathology image analysis: A comparative study of prognostic values of automatically extracted morphometric nuclear features in multispectral and red-blue-green imagery

OBJECTIVES

Multispectral imaging (MSI) has been utilized to predict the prognosis of colorectal cancer (CRC) patients, however, our understanding of the prognostic value of nuclear morphological parameters of bright-field MSI in CRC is still limited. This study was designed to compare the efficiency of MSI and standard red-green-blue (RGB) images in predicting the prognosis of CRC.

METHODS

We compared the efficiency of MS and conventional RGB images on the quantitative assessment of hematoxylin-eosin (HE) stained histopathology images. A pipeline was developed using a pixel-wise support vector machine (SVM) classifier for gland-stroma segmentation, and a marker-controlled watershed algorithm was used for nuclei segmentation. The correlation between extracted morphological parameters and the five-year disease-free survival (5-DFS) was analyzed.

RESULTS

Forty-seven nuclear morphological parameters were extracted in total. Based on Kaplan-Meier analysis, eight features derived from MS images and seven featured derived from RGB images were significantly associated with 5-DFS, respectively. Compared with RGB images, MSI showed higher accuracy, precision, and Dice index in nuclei segmentation. Multivariate analysis indicated that both integrated parameters 1 (factors negatively correlated with CRC prognosis including nuclear number, circularity, eccentricity, major axis length) and 2 (factors positively correlated with CRC prognosis including nuclear average area, area perimeter, total area/total perimeter ratio, average area/perimeter ratio) in MS images were independent prognostic factors of 5-DFS, in contrast with only integrated parameter 1 (P<0.001) in RGB images. More importantly, the quantification of HE-stained MS images displayed higher accuracy in predicting 5-DFS compared with RGB images (76.9% vs 70.9%).

CONCLUSIONS

Quantitative evaluation of HE-stained MS images could yield more information and better predictive performance for CRC prognosis than conventional RGB images, thereby contributing to precision oncology.

Convenient Synthesis of N-Alkyl-2-(3-phenyl-quinoxalin-2-ylsulfanyl)acetamides and Methyl-2-[2-(3-phenyl-quinoxalin-2-ylsulfanyl)acetylamino]alkanoates

A series of 27 new quinoxaline derivatives (N-alkyl-[2-(3-phenyl-quinoxalin-2-ylsulfanyl)]acetamides, methyl-2-[2-(3-phenylquinoxalin-2-ylsulfanyl)-acetylamino]alkanoates, and their corresponding dipeptides) were prepared from 3-phenylquinoxaline-2(1H)-thione based on the chemoselective reaction with soft electrophiles. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to study the efficacy of 27 compounds on cancer cell viability and proliferation. A total of 13 compounds (4a-c, 5, 6, 8c, 9c, 9f, 10a, 10b, 11c, 12b, and 12c) showed inhibitory action on HCT-116 cancer cells and 15 compounds (4a-c, 5, 6, 8c, 9a, 9c, 9f, 9h, 10b, 11c, 12a, 12b, and 12c) showed activity on MCF-7 cancer cells, with compound 10b exhibiting the highest inhibitory action (IC₅₀ 1.52 and 2 μg/mL, respectively) on both cell lines. The molecular modeling studies on the human thymidylate synthase (hTS) homodimer interface showed that these compounds are good binders and could selectively inhibit the enzyme by stabilizing its inactive conformation. The study also identified key residues for homodimer binding, which could be used for further optimization and development.

Anti-microbial and anti-cancer activities of Mn0.5Zn0.5DyxFe2-xO4 (x ≤ 0.1) nanoparticles

Combining two or more nanoparticles is a promising approach. Previously we have reported synthesis of nanoparticles Dysprosium (Dy) substituted with manganese (Mn) zinc (Zn) by using ultrasonication method. The five different nanoparticles (NPs) Mn0.5Zn0.5DyxFe2-xO4 (x ≤ 0.1) have been structurally and morphologically characterized but there is no report on the biological application of these NPs. In the present study, we have examined the anti-cancer, anti-bacterial, and anti-fungal activities of Mn0.5Zn0.5DyxFe2-xO4 (x ≤ 0.1) NPs. Human colorectal carcinoma cells (HCT-116) were tested with different concentrations of NPs by using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. In addition, the impact of NPs was also examined on normal cells such as human embryonic kidney cells, HEK-293. After 48 h of treatment, Mn0.5Zn0.5DyxFe2-xO4 NPs (x = 0.02, 0.04 and 0.06) showed no inhibitory action on cancer cell's growth and proliferation, whereas Mn0.5Zn0.5DyxFe2-xO4 NPs (x = 0.08 and 0.1) showed profound inhibitory action on cancer cell's growth and proliferation. However, the treatment of Mn0.5Zn0.5DyxFe2-xO4 NPs on the normal cells (HEK-293) did not show cytotoxic or inhibitory action on HEK-293 cells. The treatment of Mn0.5Zn0.5DyxFe2-xO4 NPs (x ≤ 0.1) also inhibited both the bacteria (Escherichia coli ATCC35218 and Staphylococcus aureus) with lowest MIC and MBC values of 4 and 8 mg/mL and fungus (Candida albicans) with MIC and MFC values of 4 and 8 mg/mL on treatment with x = 0.08 and 0. 1.

Al-Suhaimi E, Hussain M, Yousuf Bari M, Mehmood Ali S, Al-Jameel SS, Slimani Y, Khan FA, Baykal A. Ultrasonic Synthesis and Biomedical Application of Mn0.5Zn0.5ErxYxFe2-2xO4 Nanoparticles

In the present study, biocompatible manganese nanoparticles have been linked with zinc and iron molecules to prepare different derivatives of Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs (x = 0.02, 0.04, 0.06, 0.08, 0.10), using an ultrasonication approach. The structure, surface morphology, and chemical compositions of Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs were elucidated by X-ray diffractometer (XRD), High-resolution transmission electron microscopy (HR-TEM), scanning electron microscope (SEM), and Energy Dispersive X-Ray Analysis (EDX) techniques. The bioactivity of Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs on normal (HEK-293) and (HCT-116) colon cancer cell line was evaluated. The Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs treatment post 48 h resulted in a significant reduction in cells (via MTT assay, having an IC₅₀ value between 0.88 µg/mL and 2.40 µg/mL). The specificity of Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs were studied by treating them on normal cells line (HEK-293). The results showed that Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs did not incur any effect on HEK-293, which suggests that Mn_0.5Zn_0.5Er_xY_xFe_2-2xO₄ NPs selectively targeted the colon cancerous cells. Using Candida albicans, antifungal activity was also studied by evaluating minimum inhibitory/fungicidal concentration (MIC/MFC) and the effect of nanomaterial on the germ tube formation, which exhibited that NPs significantly inhibited the growth and germ tube formation. The obtained results hold the potential to design nanoparticles that lead to efficient bioactivity.

Ki-67 assessment-agreeability between immunohistochemistry and flow cytometry in canine lymphoma

Recent literature suggests a combination of flow cytometric determination of Ki-67 and immunophenotype as a reliable tool to classify canine lymphomas. Immunohistochemistry (IHC) on histological samples is the gold standard technique assessing Ki-67 index. Agreement between IHC and FCM derived Ki-67 indices has never been investigated. The aim of this study was to investigate the agreement between IHC and FCM in the assessment of Ki-67 expression/index, in order to evaluate whether FCM may serve as a non-invasive alternative method for the estimation of proliferative activity in canine lymphoma. Dogs with previously untreated canine lymphoma undergoing diagnostic lymphadenectomy were prospectively enrolled. Ki-67 expression/index was assessed by FCM and IHC and expressed as percentage of positive cells. 39 dogs classified by histopathology matched the inclusion criteria. With both methods, Ki-67 expression/index was higher in intermediate/high-grade lymphomas. Spearman's coefficient of correlation was ρ = 0.57; (95% CI0.33-0.75) suggesting a moderate correlation. A Bland-Altman plot revealed a negative constant bias of -3.55 (95% CI: -10.52 to 3.42) with limits of agreement from -45.71 to 38.61. The study confirmed agreement albeit with wide confidence intervals between the values of Ki-67 expression/index assessed with FCM and IHC. Discrepancies were observed in a subset of cases. Possible explanation could be that Ki-67 index in IHC is determined in the most proliferative areas of the slide, which could introduce kind of sampling bias, whereas FCM evaluates many more cells in cell suspension. Further studies are warranted to investigate this phenomenon.

The synthesis and antiproliferative activity of new N-allyl quinoxalinecarboxamides and their O-regioisomers

We have designed a series of quinoxalinepeptidomimetic derivatives based on our previously reported scaffold in an attempt to find a promising lead compound.

Evaluation of bioactivities of zinc oxide, cadmium sulfide and cadmium sulfide loaded zinc oxide nanostructured materials prepared by nanosecond pulsed laser

The present study reports the preparation of cadmium sulfide (CdS) loaded zinc oxide (ZnO) nanostructured semiconductor material and its anti-bioactivity studies against cancerous and fungus cells. For composite preparation, two different mass ratios of CdS (10 and 20%) were loaded on ZnO (10%CdS/ZnO, 20%CdS/ZnO) using a 532 nm pulsed laser ablation in water media. The structural and morphological analyses confirmed the successful loading of nanoscaled CdS on the surface of ZnO particles, ZnO particles were largely spherical with average size ~50 nm, while CdS about 12 nm in size. The elemental and electron diffraction analyses reveal that the prepared composite, CdS/ZnO contained both CdS and ZnO, thus reaffirming the production of CdS loaded ZnO. The microscopic examination and MTT assay showed the significant impact of ZnO, CdS, and CdS loaded ZnO on human colorectal carcinoma cells (HCT-116 cells). Our results show that the prepared ZnO had better anticancer activities than individual CdS, and CdS loaded ZnO against cancerous cells. For antifungal efficacy, as-prepared nanomaterials were investigated against Candida albicans by examining minimum inhibitory/fungicidal concentration (MIC/MFC) and morphogenesis. The lowest MIC (0.5 mg/mL), and MFC values (1 mg/mL) were found for 10 and 20%CdS/ZnO. Furthermore, the morphological analyses reveal the severe damage of the cell membrane upon exposure of Candida strains to nanomaterials. The present study suggests that ZnO, CdS, and CdS loaded ZnO nanostructured materials possess potential anti-cancer and anti-fungal activities.

Synthesis of Ni0.5Co0.5-xCdxFe1.78Nd0.02O4 (x ≤ 0.25) nanofibers by using electrospinning technique induce anti-cancer and anti-bacterial activities

Here we report the electrospinning synthesis of Cd-substituted Ni-Co ferrite Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) nanofiber (NFs) with a very low concentration of Nd as a dopant. The structure and surface morphology of the Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) NFs were analyzed by X-ray powder pattern (XRD), transmission and scanning electron microscopes (TEM) along with Energy-dispersive X-ray (EDX). We have examined the biological applications of the Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) NFs on both cancerous cells and bacterial cells. We have found that Ni_0.5Co_0.5-xCd_xFe_1.78Nd_0.02O₄ (x ≤ 0.25) NFs produced inhibitory action on the human colorectal carcinoma cells (HEK-293) and also showed inhibitory action on the bacterial strains (S. aureus and E. coli) respectively. Finally, this is the first report on the synthesis of Cd- substituted Co-Ni ferrite nanofibers using electrospinning technique exhibiting anti-cancer and anti-bacterial activities.Communicated by Ramaswamy H. Sarma.

Synthesis of niobium substituted cobalt-nickel nano-ferrite (Co0.5Ni0.5NbxFe2-xO4 (x ≤ 0.1) by hydrothermal approach show strong anti-colon cancer activities

The combination of two or more nanoparticles found to be effective strategy to synthesize nanocomposites for better drug delivery and treatment. In the present study, we have combined cobalt (Co), nickel (Ni), niobium (Nb), and iron oxide (Fe₂O₄) and prepared niobium substituted cobalt-nickel nano-ferrite nanocomposites (Co_0.5Ni_0.5Nb_xFe_2-xO₄ (x ≤ 0.1) by using hydrothermal approach. We have characterized the structure and morphology of nanocomposites by using XRD, EDX, TEM and SEM methodologies. We have examined the impact of nanocomposites (Co_0.5Ni_0.5Nb_xFe_2-xO₄ (x ≤ 0.1) on cancerous cells (human colorectal carcinoma cells, HCT-116) by using MTT assay. We have also checked the impact of nanocomposites on normal and non-cancerous cells (human embryonic kidney cells, HEK-293) to confirm the specificity of their actions. Post- 48 h treatment of Co_0.5Ni_0.5Nb_xFe_2-xO₄ (x ≤ 0.1) led to dose-dependent inhibition of cancer cells growth and proliferation. However, no cytotoxic effect was observed on the normal cells (HEK-293). In addition, DAPI stained nuclear DNA staining analysis demonstrates that the Co_0.5Ni_0.5Nb_xFe_2-xO₄ (x ≤ 0.1) treatment also caused nuclear DNA disintegration which is the marker for programmed cell death. These results demonstrate that synthesized nanocomposites Co_0.5Ni_0.5Nb_xFe_2-xO₄ (x ≤ 0.1) selectively target the colon cancer cells and induce cancer cell death.Communicated by Ramaswamy H. Sarma.

Newly synthesized 3-(4-chloro-phenyl)-3-hydroxy-2,2-dimethyl-propionic acid methyl ester derivatives selectively inhibit the proliferation of colon cancer cells

A series of 24 compounds were synthesized based on structure modification of the model methyl-3-(4-chlorophenyl)-3-hydroxy-2,2-dimethylpropanoate as potent HDACIs. Saponification and hydrazinolysis of the model ester afforded the corresponding acid and hydrazide, respectively. The model ester was transformed into the corresponding trichloroacetimidate or acetate by the reaction with trichloroacetonitrile and acetic anhydride, respectively. N-Alkyl-3-(4-chlorophenyl)-3-hydroxy-2,2-dimethylpropan-amides and methyl-2-[(3-(4-chlorophenyl)-3-hydroxy-2,2-dimethylpropanoyl)amino] alkanoates were obtained by the reaction of corresponding acid or hydrazide with amines and amino acid esters via DCC and azide coupling methods. Methyl-3-aryl-3-(4-chlorophenyl)-2,2-dimethylpropanoates were obtained in good yields and short reaction time from the corresponding trichloroacetimidate or acetate by the reaction with C-active nucleophiles in the presence of TMSOTf (0.1 eq.%) via C–C bond formation. The antiproliferative and apoptotic activity were further studied with molecular docking. The 48 post-treatments showed that out of 24 compounds, 12 compounds showed inhibitory actions on HCT-116 cells, we have calculated the inhibitory action (IC₅₀) of these compounds on HCT-116 and we have found that the IC₅₀ values were in between 0.12 mg mL⁻¹ to 0.81 mg mL⁻¹. The compounds (7a & 7g) showed highest inhibitory activity (0.12 mg mL⁻¹), whereas compound 7d showed the lowest inhibitory activity (0.81 mg mL⁻¹). We have also examined inhibitory action on normal and non-cancerous cells (HEK-293 cells) and confirmed that action of these compounds was specific to cancerous cells. The cancerous cells were also examined for nuclear disintegration through staining with DAPI, (4′,6-diamidino-2-phenylindole) is a blue-fluorescent DNA stain, and we have found that there was loss of DAPI staining in the compound treated cancerous cells. The compounds were found to potentially act through the HSP90 and TRAP1 mediated signaling pathway. Compounds 7a and 7g showed the highest selectivity to TRAP1 which explained its superior activity.

A series of 24 compounds were synthesized based on structure modification of the model methyl-3-(4-chlorophenyl)-3-hydroxy-2,2-dimethylpropanoate as potent HDACIs.

Synthesis and biological characterization of Mn0.5Zn0.5EuxDyxFe1.8-2xO4 nanoparticles by sonochemical approach

Metallic nanoparticles (NPs) possess unique properties which makes them attractive candidates for various applications especially in field of experimental medicine and drug delivery. Many approaches were developed to synthesize divers and customized metallic NPs that can be useful in many areas such as, experimental medicine, drug design, drug delivery, electrical and electronic engineering, electrochemical sensors, and biochemical sensors. Among different metallic nanoparticles, manganese (Mn) NPs are the most prominent materials, in the present study, we have synthetized unique Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs by using ultrasonication method (x ≤ 0.1). The structure, and surface morphology of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs was characterized by XRD, SEM, TEM and EDX methods. We have examined the biological effects of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs on both normal (HEK-293) and cancerous (HCT-116) cells. We have found that the treatment of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs post 48 h, showed significant decline in cancer cells population as revealed by MTT assay. The IC₅₀ value of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs was ranged between (2.35 μg/mL to 2.33 μg/mL). To check the specificity of the actions, we found that the treatment of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs did not produce any effects on the normal cells, which suggest that Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs selectively targeted the cancerous cells. The anti-bacterial properties of Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs were also evaluated by MIC and MBC assays. We suggest that Mn_0.5Zn_0.5Dy_xEu_xFe_1.8-2xO₄ NPs produced by sonochemical method possess potential anti-cancer and anti-bacterial capabilities.

Synthesis of Mn0.5Zn0.5SmxEuxFe1.8-2xO4 Nanoparticles via the Hydrothermal Approach Induced Anti-Cancer and Anti-Bacterial Activities

Manganese metallic nanoparticles are attractive materials for various biological and medical applications. In the present study, we synthesized unique Mn_0.5Zn_0.5Sm_xEu_xFe_1.8−2xO₄ (0.01 ≤ x ≤ 0.05) nanoparticles (NPs) by using the hydrothermal approach. The structure and surface morphology of the products were determined by X-ray powder diffraction (XRD), transmission electron and scanning electron microcopies (TEM and SEM), along with energy dispersive X-ray spectroscopy (EDX). We evaluated the impact of Mn_0.5Zn_0.5Sm_xEu_xFe_1.8−2xO₄ NPs on both human embryonic stem cells (HEK-293) (normal cells) and human colon carcinoma cells (HCT-116) (cancerous cells). We found that post-48 h of treatment of all products showed a significant decline in the cancer cell population as revealed by microscopically and the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium (MTT) assay. The inhibitory concentration (IC₅₀) values of the products ranged between 0.75 and 2.25 µg/mL. When tested on normal and healthy cells (HEK-293), we found that the treatment of products did not produce any effects on the normal cells, which suggests that all products selectively targeted the cancerous cells. The anti-bacterial properties of the samples were also evaluated by Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) assays, which showed that products also inhibited the bacterial growth.

Convenient Synthesis and Anticancer Activity of Methyl 2-[3-(3-Phenyl-quinoxalin-2-ylsulfanyl)propanamido]alkanoates and N-Alkyl 3-((3-Phenyl-quinoxalin-2-yl)sulfanyl)propanamides

A series of methyl 2-[3-(3-phenyl-quinoxalin-2-ylsulfanyl)propanamido]alkanoates and their corresponding hydrazides and N-alkyl 3-((3-phenylquinoxalin-2-yl)sulfanyl)propanamides were prepared on the basis of the chemoselective Michael reaction of acrylic acid with the parent substrate 3-phenylquinoxaline-2(1H)-thione. The parent thione was produced by a convenient novel thiation method from the corresponding 3-phenylquinoxalin-2(1H)-one. The chemical structures of the newly synthesized compounds were confirmed by elemental analyses, ¹H and ¹³C NMR. The antiproliferative activity of the synthesized compounds was tested against human HCT-116 and MCF-7 cell lines. Out of 25 screened derivatives, 10 active compounds exhibited IC₅₀'s in the range 1.9-7.52 μg/mL on the HCT-116, and 17 active compounds exhibited IC₅₀'s in the range 2.3-6.62 μg/mL on the MCF-7 cell lines compared to the reference drug doxorubicin (IC₅₀ 3.23 μg/mL). The structure-activity relationship of the tested compounds was studied through their binding affinity to the human thymidylate synthase allosteric site in silico using molecular docking and proved the quinoxaline ring as a suitable scaffold carrying a peptidomimetic side chain in position 3.

FMSP-Nanoparticles Induced Cell Death on Human Breast Adenocarcinoma Cell Line (MCF-7 Cells): Morphometric Analysis

Currently, breast cancer treatment mostly revolves around radiation therapy and surgical interventions, but often these treatments do not provide satisfactory relief to the patients and cause unmanageable side-effects. Nanomaterials show promising results in treating cancer cells and have many advantages such as high biocompatibility, bioavailability and effective therapeutic capabilities. Interestingly, fluorescent magnetic nanoparticles have been used in many biological and diagnostic applications, but there is no report of use of fluorescent magnetic submicronic polymer nanoparticles (FMSP-nanoparticles) in the treatment of human breast cancer cells. In the present study, we tested the effect of FMSP-nanoparticles on human breast cancer cells (MCF-7). We tested different concentrations (1.25, 12.5 and 50 µg/mL) of FMSP-nanoparticles in MCF-7 cells and evaluated the nanoparticles response morphometrically. Our results revealed that FMSP-nanoparticles produced a concentration dependent effect on the cancer cells, a dose of 1.25 µg/mL produced no significant effect on the cancer cell morphology and cell death, whereas dosages of 12.5 and 50 µg/mL resulted in significant nuclear augmentation, disintegration, chromatic condensation followed by dose dependent cell death. Our results demonstrate that FMSP-nanoparticles induce cell death in MCF-7 cells and may be a potential anti-cancer agent for breast cancer treatment.

Identifying tumor in pancreatic neuroendocrine neoplasms from Ki67 images using transfer learning

The World Health Organization (WHO) has clear guidelines regarding the use of Ki67 index in defining the proliferative rate and assigning grade for pancreatic neuroendocrine tumor (NET). WHO mandates the quantification of Ki67 index by counting at least 500 positive tumor cells in a hotspot. Unfortunately, Ki67 antibody may stain both tumor and non-tumor cells as positive depending on the phase of the cell cycle. Likewise, the counter stain labels both tumor and non-tumor as negative. This non-specific nature of Ki67 stain and counter stain therefore hinders the exact quantification of Ki67 index. To address this problem, we present a deep learning method to automatically differentiate between NET and non-tumor regions based on images of Ki67 stained biopsies. Transfer learning was employed to recognize and apply relevant knowledge from previous learning experiences to differentiate between tumor and non-tumor regions. Transfer learning exploits a rich set of features previously used to successfully categorize non-pathology data into 1,000 classes. The method was trained and validated on a set of whole-slide images including 33 NETs subject to Ki67 immunohistochemical staining using a leave-one-out cross-validation. When applied to 30 high power fields (HPF) and assessed against a gold standard (evaluation by two expert pathologists), the method resulted in a high sensitivity of 97.8% and specificity of 88.8%. The deep learning method developed has the potential to reduce pathologists’ workload by directly identifying tumor boundaries on images of Ki67 stained slides. Moreover, it has the potential to replace sophisticated and expensive imaging methods which are recently developed for identification of tumor boundaries in images of Ki67-stained NETs.

A Comparative Performance Analysis of Multispectral and RGB Imaging on HER2 Status Evaluation for the Prediction of Breast Cancer Prognosis

Despite the extensive application of multispectral imaging (MSI) in biomedical multidisciplinary researches, there is a paucity of data available regarding the implication of MSI in tumor prognosis prediction. We compared the behaviors of multispectral (MS) and conventional red-green-blue (RGB) images on assessment of human epidermal growth factor receptor 2 (HER2) immunohistochemistry to explore their impact on outcome in patients with invasive breast cancer (BC). Tissue microarrays containing 240 BC patients were introduced to compare the performance of MS and RGB imaging methods on the quantitative assessment of HER2 status and the prognostic value of 5-year disease-free survival (5-DFS). Both the total and average signal optical density values of HER2 MS and RGB images were analyzed, and all patients were divided into two groups based on the different 5-DFS. The quantification of HER2 MS images was negatively correlated with 5-DFS in lymph node–negative and –positive patients (P < .05), but RGB images were not in lymph node–positive patients (P = .101). Multivariate analysis indicated that the hazard ratio (HR) of HER2 MS was higher than that of HER2 RGB (HR = 2.454; 95% confidence interval [CI], 1.636-3.681 vs HR = 2.060; 95% CI, 1.361-3.119). Additionally, area under curve (AUC) by receiver operating characteristic analysis for HER2 MS was greater than that for HER2 RGB (AUC = 0.649; 95% CI, 0.577-0.722 vs AUC = 0.596; 95% CI, 0.522-0.670) in predicting the risk for recurrence. More importantly, the quantification of HER2 MS images has higher prediction accuracy than that of HER2 RGB images (69.6% vs 65.0%) on 5-DFS. Our study suggested that better information on BC prognosis could be obtained from the quantification of HER2 MS images and MS images might perform better in predicting BC prognosis than conventional RGB images.

Quantum dot-based molecular imaging of cancer cell growth using a clone formation assay

This aim of the present study was to investigate clonal growth behavior and analyze the proliferation characteristics of cancer cells. The MCF‑7 human breast cancer cell line, SW480 human colon cancer cell line and SGC7901 human gastric cancer cell line were selected to investigate the morphology of cell clones. Quantum dot‑based molecular targeted imaging techniques (which stained pan‑cytokeratin in the cytoplasm green and Ki67 in the cell nucleus yellow or red) were used to investigate the clone formation rate, cell morphology, discrete tendency, and Ki67 expression and distribution in clones. From the cell clone formation assay, the MCF‑7, SW480 and SGC7901 cells were observed to form clones on days 6, 8 and 12 of cell culture, respectively. These three types of cells had heterogeneous morphology, large nuclear:cytoplasmic ratios, and conspicuous pathological mitotic features. The cells at the clone periphery formed multiple pseudopodium. In certain clones, cancer cells at the borderline were separated from the central cell clusters or presented a discrete tendency. With quantum dot‑based molecular targeted imaging techniques, cells with strong Ki67 expression were predominantly shown to be distributed at the clone periphery, or concentrated on one side of the clones. In conclusion, cancer cell clones showed asymmetric growth behavior, and Ki67 was widely expressed in clones of these three cell lines, with strong expression around the clones, or aggregated at one side. Cell clone formation assay based on quantum dots molecular imaging offered a novel method to study the proliferative features of cancer cells, thus providing a further insight into tumor biology.