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Gene amplifications of PIK3CA or KRAS induce a downstream activation of the AKT-mTOR or RAF-ERK-pathways. Interactions of the active AKT pathway have been implicated in the inflammatory tumor microenvironment. Nothing is known about these interactions or prognostic power in esophageal adenocarcinoma (EAC). We retrospectively analyzed a large cohort of 685 EAC considering KRAS and PIK3CA gene amplification using fluorescence in situ hybridization (FISH) and immunohistochemistry. These results were correlated with clinical and molecular data as well as the inflammatory tumor microenvironment. Amplifications of KRAS were seen in 94 patients (17.1%), PIK3CA amplifications in 23 patients (5.0%). KRAS amplifications significantly correlated with nodal positive patients and poorer overall survival (OS) in the subgroup without neoadjuvant treatment (p = 0.004), coamplifications of Her2 (p = 0.027), and TP53 mutations (p = 0.016). PIK3CA amplifications significantly correlated with a high amount of tumor infiltrating T cells (p = 0.003) and showed a tendency to better OS (p = 0.068). A correlation with checkpoint makers (PD-L1, LAG3, VISTA, TIM3, IDO) could not be revealed. Our findings are the first to link the KRAS amplified genotype with lymphonodal positivity and poor prognosis and the PIK3CA-amplified genotype with a T cell–rich microenvironment in EAC. Future studies must show whether these two genotype subgroups can be therapeutically influenced. A dual inhibition of MEK and SHP2T could be effective in the subgroup of KRAS amplified EACs and an immune checkpoint blockade may prove to be particularly promising in the subgroup of PIK3CA-amplified EACs.

The aim of the present study was to evaluate the mutation and amplification status of the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA) gene, as well as the association with clinicopathological characteristics and prognosis, in Japanese patients with cervical cancer. Fluorescence in situ hybridization and polymerase chain reaction were performed to assess PIK3CA gene amplification and mutation. The inhibitors temsirolimus and NVP-BEZ235 were used to inactivate the phosphatidylinositide 3-kinase (PI3K)/AKT serine/threonine kinase (AKT)/mechanistic target of rapamycin kinase (mTOR) pathway to clarify the roles of PI3K/AKT activation in cervical carcinoma cells harboring associated mutations. Four somatic point mutations (4/71, 5.6%) were found in exon 20 in cervical squamous cell carcinoma samples, whereas three (3/53, 5.7%) were found in exon 9 in cervical adeno/adenosquamous cell carcinoma samples. Amplification of PIK3CA was also observed in this study and amplification was more commonly found in adeno/adenosquamous carcinomas than in cervical squamous cell carcinomas (20.7 vs. 1.4%, respectively, P=0.0003). No significant correlation was obesrved between PIK3CA amplification and progression free survival (P=0.7576) or overall survival (P=0.8859). Moreover, no association between PIK3CA mutation and sensitivity to PI3K/AKT/mTOR inhibitors was observed in cervical carcinoma cells. These results suggest that in Japanese patients with cervical cancer, PIK3CA mutation and amplification cannot act as biomarkers for individualized molecular targeted therapy.

Phosphatidyl-inositol 3-kinase/Akt/mammalian target of rapamycin pathway (PI3K/Akt/mTOR) is a critical signal transduction pathway in mammalian cellular biology, and is important to energy homeostasis, growth and survival. Activation of the pathway is an early event in head and neck squamous cell carcinoma (HNSCC) carcinogenesis. Moreover, PI3K/Akt/mTOR is the most commonly mutated pathway in HNSCC, with striking prevalence in human papillomavirus (HPV) associated disease. Genomic gain of function can also be conferred by PIK3CA gene amplification or loss of phosphatase and tensin homolog, the negative regulator of PI3K. Given the importance of PI3K/Akt/mTOR signaling across the neoplastic spectrum, pathway inhibitors are of unique interest in HNSCC. This review will summarize current knowledge, highlight differences in HPV(+) and HPV(-) disease and discuss therapeutic agents in various phases of clinical development.

Background: Phosphatidylinositol3-kinase, catalytic, α-polypeptide (PIK3CA) gene is frequently amplified in ovarian carcinoma (OC). To the best of our knowledge, there is a dearth of published reports about the amplification of the PIK3CA gene among Sudanese women with OC. This study aimed to detect the amplification of the PIK3CA gene and its relationship with clinicopathological variables among Sudanese women with OC. Methods: This cross-sectional study included 90 ovarian cases: 83 cases of women diagnosed with OC at Omdurman Maternity Hospital in the period 2013-2018; 7 cases of women with normal ovarian tissues were used as a control to normalize the results. Formalin-fixed paraffin-embedded tissue sections (FFPE) were used to extract RNA at the Institute of Endemic Diseases, Sudan. PIK3CA gene amplification was assessed using quantitative real-time PCR. Results: Amplification of PIK3CA was observed in 33.7% (n = 28/83) of women, with a high frequency in women with clear cell (66.7%; n = 4/6), undifferentiated (50.0%; n = 1/2), serous (35.5%; n = 11/31), mucinous (33.3%; n = 4/12),other (30.8%; n = 4/13), and endometrioid (21.1%; n = 4/19) carcinomas. High frequency was seen in women with higher (39.5%; n = 17/43) rather than in lower grade carcinomas (27.5%; n = 11/40), and in older (43.4%; n = 11/32) rather than younger (30.0%; n = 12/40) women. No significant association between PIK3CA amplification and tumor histologic type, grade, and age of women was observed (Fisher’s Exact test: p = 0.660, 0.698 and 0.687, respectively). Conclusion: PIK3CA gene amplification occurs in about one third of Sudanese women with OC, more frequently in high tumor grades and older women, but not to a statistically significant level. These findings support previous studies suggesting that oncogenic PIK3CA has an essential role in OC progression and may offer a strategy for exact targeted therapy and prognostic evaluation

PI3Ks (phosphatidylinositol 3-kinases) are lipid kinases that regulate signalling pathways involved in cell proliferation, motility, and adhesion. Somatic mutations and amplification of the PIK3CA gene have been reported in various types of human cancers. However, little is known about the frequency and prognosis role of PIK3CA activation in nasopharyngeal carcinoma (NPC). This study was conducted with the aim to screen for PIK3CA mutations in the two hot spot regions (exons 9 and 20) and to investigate for the PIK3CA gene amplification combined with the expression analysis of the phosphorylated Akt (pAkt). We showed that among 88 specimens, none had mutation in the helical domain (exon 9) and only one (1.13%) had mutation in the kinase domain (exon 20). On the other hand, PIK3CA gene amplification was found in 21.6% of cases and was strongly associated with distant metastasis (P = 0.002), lymph node involvement (P = 0.032), and advanced tumor stage (P < 0.001). Moreover, patients with PIK3CA copy number gain have a significant reduced overall survival time (P log rank = 0.02). We concluded that PIK3CA gene amplification is frequent in NPC and occurs in the advanced stage of NPC. Moreover, our finding emphasizes the association of PIK3CA gene amplification with worse prognosis in nasopharyngeal carcinoma.

Using a DNA microarray approach to screen for gene copy number changes in 20 colorectal (CR) carcinoma samples and filtering for high-level DNA copy number changes, we detected an amplicon at 3q26 containing the PIK3CA gene. Fluorescence in situ hybridization was employed for evaluation of PIK3CA amplification on a progression CR tissue microarray containing 448 CR carcinomas, normal mucosa, and adenomas with follow-up information. PIK3CA amplification (ratio PIK3CA/centromere 3≥2.0) was found in 38% of cancers, while another 19% of tumours had PIK3CA gains (ratio >1.0 but

To investigate the clinicopathologic characteristics and the prognostic impact of PIK3CA gene amplification in curatively resected esophageal squamous cell carcinoma (ESCC). Using 534 curatively resected ESCCs, the PIK3CA gene copy number was evaluated with fluorescent in situ hybridization. PIK3CA amplification was defined as PIK3CA/centromere 3 ratio is ≥ 2.0 or average number of PIK3CA signals/tumor cell nucleus ≥ 5.0. PIK3CA mutations in exon 9 and 20, encoding the highly conserved helical and kinase domains were assessed by direct sequencing in 388 cases. PIK3CA amplification was detected in 56 (10.5%) cases. PIK3CA amplification was significantly associated with higher T-stage (P=0.026) and pathologic stage (P=0.053). PIK3CA amplification showed a significantly shorter disease free survival (DFS) compared with that of non-amplified group (33.4 vs 63.1 months, P=0.019). After adjusting for gender, tumor location, pathologic stage, histologic grade and adjuvant treatment, PIK3CA amplification was significantly associated with a shorter DFS (adjusted hazard ratio [AHR] 1.53; 95% CI, 1.10-2.17; P=0.02). Though the statistical insignificance, PIK3CA amplification showed tendency of shorter OS (52.1 vs 96.5 moths, P=0.116). PIK3CA mutations were detected in 6 (1.5%) of 388 cases; 5 cases with exon 9 mutations in E545K while one exon 20 mutation in H1047L. PIK3CA amplification is a frequent oncogenic alteration and associated with shorter survival, suggesting its role as a prognostic biomarker in resected ESCC. PIK3CA amplification may represent a promising therapeutic target for ESCC.

Molecular alterations in PIK3CA oncogene that encodes the p110α catalytic subunit of phosphatidylinositol 3-kinase (PI3K p110α) are commonly found in human cancers. In this study, we examined the expression of PI3K p110α and PIK3CA gene amplification in 74 nasopharyngeal carcinoma (NPC) cases. Immunohistochemical staining demonstrated overexpression of PI3K p110α protein in 44.6 % (33/74) of NPCs and 4.8 % (2/42) of the adjacent normal nasopharyngeal mucosa. Copy number of PIK3CA gene was successfully analyzed in 51 of the total NPC cases and 19 non-malignant nasopharynx tissues by quantitative real-time PCR. Using mean + 2(standard deviation) of copy numbers in the non-malignant nasopharynx tissues as a cutoff value, PIK3CA copy number gain was found in 10 of 51 (19.6 %) NPC cases. High PI3K p110α expression level was correlated with increased PIK3CA copy number (Spearman’s rho =0.324, P = 0.02). PI3K p110α expression and PIK3CA copy number did not associate with Akt phosphorylation, and patient and tumor variables. This study suggests that PI3K p110α overexpression, which is attributed, at least in part, to PIK3CA gene amplification, may contribute to NPC pathogenesis. However, these molecular aberrations may not be responsible for activation of Akt signaling in NPC.

Phosphatidylinositol 3′-kinases are lipid kinases with important roles in neoplasia. Recently, a very high frequency of somatic mutations in PIK3CA has been reported among a large series of colorectal cancers. However, the relevance of PIK3CA mutation in other cancer types remains unclear because of the limited number of tumors investigated. We have screened a total of 284 primary human tumors for mutations in all coding exons of PIK3CA using a combination of single stranded conformational polymorphism and denaturing high-performance liquid chromatography analysis. Among 70 primary breast cancers, 40% (28 of 70) harbored mutations in PIK3CA, making it the most common mutation described to date in this cancer type. Mutations were not associated with histologic subtype, estrogen receptor status, grade or presence of tumor in lymph nodes. Among the primary epithelial ovarian cancers only 11 of 167 (6.6%) contain somatic mutations, but there was a clear histologic subtype bias in their distribution. Only 2 of 88 (2.3%) of serous carcinomas had PIK3CA mutations compared with 8 of 40 (20.0%) endometrioid and clear cell cancers, which was highly significant (P = 0.001). In contrast, PIK3CA gene amplification (>7-fold) was common among all histologic subtypes (24.5%) and was inversely associated with the presence of mutations. Overall, PIK3CA mutation or gene amplification was detected in 30.5% of all ovarian cancers and 45% of the endometrioid and clear cell subtypes. Our study is the first direct evidence that PIK3CA is an oncogene in ovarian cancer and greatly extends recent findings in breast cancer.

A family of PI3Ks is the lipid kinases, which enhance intracellular pools of phosphatidyl inositol 3,4,5-tri-phosphate (PIP3) through phosphorylating its precursor. Amplifications and deletions of genes, as well as somatic missense of the PIK3CA gene have been described in many human cancer varieties, including of the brain, colon, liver, lung and stomach. Immunohistochemistry and Real-time quantitative PCR tests were used to determine the PIK3CA gene amplification (gene copy number) and to detect protein expression, respectively. The results obtained were analysed and the ratio of PIK3CA to β-actin gene copy number was calculated. Positive gene amplification of PIK3CA was appointed as a copy number of ≥4. Also, PI3K p110α protein expression was scored from 0 to 3+ and the scores of 2+ and 3+ were considered as positive for PI3K p110α protein expression. We studied 50 breast carcinoma samples for PI3K p110α protein expression and PIK3CA gene copy numbers. In general, 36 out of 50 (72%) breast carcinoma samples showed a significant increase in PIK3CA gene amplification. 12 out of 50 (24%) showed positive staining, and 38 out of 50 (76%) showed negative staining for PI3K p110α expression. We have identified no significant relationship between PIK3CA amplification, race (p= 0.630) and histological type (p=0. 731) in breast carcinoma, but correlation of PIK3CA amplification and age showed a significant relationship (p=0. 003) between them. No significant relationship has been identified in correlation of PI3K p110α protein expression compared to age (p=0. 284), race (p=0. 546) and histological type (p=0. 285). Amplification of PIK3CA was frequent in breast carcinoma and occurs in stages of breast carcinoma. Our result shows that there is a relationship between gene amplification and age in breast carcinoma. We suggest that PIK3CA is significant in breast tumorigenesis serve as a prevalent mechanism contributes to the oncogenic activation pathway of PIK3CA in breast cancer.

The phosphatidylinositol 3-kinases (PI3K) are a family of enzymes that relay important cellular growth control signals. Recently, a large-scale mutational analysis of eight PI3K and eight PI3K-like genes revealed somatic mutations in PIK3CA, which encodes the p110α catalytic subunit of class IA PI3K, in several types of cancer, including glioblastoma multiforme. In that report, 4 of 15 (27%) glioblastomas contained potentially oncogenic PIK3CA mutations. Subsequent studies, however, showed a significantly lower mutation rate ranging from 0% to 7%. Given this disparity and to address the relation of patient age to mutation frequency, we examined 10 exons of PIK3CA in 73 glioblastoma samples by PCR amplification followed by direct DNA sequencing. Overall, PIK3CA mutations were found in 11 (15%) samples, including several novel mutations. PIK3CA mutations were distributed in all sample types, with 18%, 9%, and 13% of primary tumors, xenografts, and cell lines containing mutations, respectively. Of the primary tumors, PIK3CA mutations were identified in 21% and 17% of pediatric and adult samples, respectively. No evidence of PIK3CA gene amplification was detected by quantitative real-time PCR in any of the samples. This study confirms that PIK3CA mutations occur in a significant number of human glioblastomas, further indicating that therapeutic targeting of this pathway in glioblastomas is of value. Moreover, this is the first study showing PIK3CA mutations in pediatric glioblastomas, thus providing a molecular target in this important pediatric malignancy. (Mol Cancer Res 2006;4(10):709–14)

We have investigated 92 non-small cell lung cancer tissues and found 11 PIK3CA amplification. PIK3CA amplification incidence was significantly higher in male, smoker and squamous cell carcinoma patients. Among 11 patients with PIK3CA amplification, two patients harbored a PIK3CA mutation. There was significant difference in survival between the patients with PIK3CA normal copy number and the patients with PIK3CA amplification.

PIK3CA gene amplification and mutations have been identified in many types of tumors, suggesting the deregulation of PI3K/AKT/mTOR axis plays pivotal roles in tumorigenesis and development. K-Ras/Raf mutation is recognized as one of the key drug resistant factors for tumors against TKIs. HM-032 was reported here as a potent, selective and reversible ATP-competitive PI3K/mTOR dual inhibitor with special apoptotic activity in tumor cells harboring K-Ras mutations. HM-032 showed potent kinase inhibition with IC50 of 0.0008, 0.002, 0.001, 0.002 and 0.001 µM on PI3Kα, β, δ, ≤ and mTOR, respectively. In human prostate PC3 cells, it inhibited p-AKTS473, p-S6 and p-4EPB1 with IC50s of 0.002, 0.015 and 0.056 μM. Of the 89 tumor cell lines from lung, colon, breast, ovarian, and other tumor types, it was found that tumor cells with HER2 gene amplification, or PIK3CA mutation were relatively more sensitive to HM-032. Attractively, HM-032 showed apoptotic induction activity in the tumor cells harboring Ras/Raf mutations through inhibiting p-Erk and increasing gene expression of pro-apoptotic protein Bim. This result suggested that HM-032 might bring benefits to patients carrying K-Ras/Raf mutations in the clinic. Consistent with in vitro studies, HM-032 exhibited significant tumor growth inhibition in a dose dependent manner on multiple human xenograft models, including breast tumor MDA-MB-361(PIK3CAE545K, Her2 amplification), lung tumors H460 (PIK3CAE545K, K-RasQ61H) and A549 (LKB1 del, K-RasG12S), and glioblastoma U87MG (PTEN del) after 3 weeks oral dosing. Correspondingly, decrease of p-AKT and p-S6 was observed in the tumor xenograft tissues upon treatment with HM-032. In addition, HM-032 exhibited unique in vivo PK properties characterized by low clearance and long t1/2, which supported the intermittent dosing schedule in xenograft models. Based on the pre-clinical study results, HM-032 is anticipated to be a promising agent against solid tumors including carrying Ras/Raf mutations. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1808. doi:1538-7445.AM2012-1808

Introduction Gene amplification is an important genetic change in cancer cells. We investigated the prevalence, clinicopathological characteristics, and prognostic value of NKX2-1 (also known as TTF-1 ) , SETDB1, MET, HER2, SOX2, FGFR1, and PIK3CA amplification in Japanese patients with non–small-cell lung cancer (NSCLC). Methods The copy numbers of the seven above-mentioned genes were assessed using fluorescence in situ hybridization in a tissue microarray containing 282 surgically resected NSCLC specimens (164 adenocarcinoma [AC], 99 squamous cell carcinoma [SCC], and 19 others). Clinicopathological information were obtained from the medical records. Results NKX2-1, SETDB1, MET, HER2, SOX2, FGFR1, and PIK3CA gene amplification were observed in 30 of 277 (10.8%), 16 of 280 (5.7%), 38 of 278 (13.7%), 8 of 270 (3.0%), 34 of 278 (12.2%), 18 of 282 (6.4%), and 53 of 278 (19.1%) cases, respectively. Coamplification was detected in 16 of 156 (10.3%) AC patients and 35 of 93 (37.6%) SCC patients ( p NKX2-1 amplification was significantly related to an AC histology ( p = 0.004), whereas SOX2, FGFR1, and PIK3CA amplifications were related to a SCC histology (p NKX2-1 and SETDB1 amplifications were markers of a shorter survival period. A multivariate Cox proportional hazards model revealed that NKX2-1 amplification was an independent predictor of poor survival (hazard ratio, 2.938; 95% confidence interval, 1.434–6.022; p = 0.003). Coamplification had impact on patient outcome in AC but not in entire NSCLC and SCC. Conclusions The amplification status differed among the histological types of NSCLC. NKX2-1 amplification was an independent and the most practically important predictor of a poor prognosis among Japanese patients with AC.